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ΓòÉΓòÉΓòÉ 1. -Preface- ΓòÉΓòÉΓòÉ

Copyright (C) 1992, 1993 Signum Support AB Copyright (C) 1993, 1994 Free
Software Foundation, Inc.

Permission is granted to make and distribute verbatim copies of this manual
provided the copyright notice and this permission notice are preserved on all
copies.

Permission is granted to copy and distribute modified versions of this manual
under the conditions for verbatim copying, provided also that the entire
resulting derived work is distributed under the terms of a permission notice
identical to this one.

Permission is granted to copy and distribute translations of this manual into
another language, under the above conditions for modified versions, except that
this permission notice may be stated in a translation approved by the Free
Software Foundation.


ΓòÉΓòÉΓòÉ 2. Overview ΓòÉΓòÉΓòÉ

 This chapter is for people who have never used CVS, and perhaps have never
 used version control software before.

 If you are already familiar with CVS and are just trying to learn a particular
 feature or remember a certain command, you can probably skip everything here.

 What is CVS?                  What you can do with CVS
 What is CVS not?              Problems CVS doesn't try to solve
 A sample session              A tour of basic CVS usage


ΓòÉΓòÉΓòÉ 2.1. What is CVS? ΓòÉΓòÉΓòÉ

 CVS is a version control system.  Using it, you can record the history of your
 source files.

 For example, bugs sometimes creep in when software is modified, and you might
 not detect the bug until a long time after you make the modification. With
 CVS, you can easily retrieve old versions to see exactly which change caused
 the bug.  This can sometimes be a big help.

 You could of course save every version of every file you have ever created.
 This would however waste an enormous amount of disk space.  CVS stores all the
 versions of a file in a single file in a clever way that only stores the
 differences between versions.

 CVS also helps you if you are part of a group of people working on the same
 project.  It is all too easy to overwrite each others' changes unless you are
 extremely careful. Some editors, like GNU Emacs, try to make sure that the
 same file is never modified by two people at the same time.  Unfortunately, if
 someone is using another editor, that safeguard will not work.  CVS solves
 this problem by insulating the different developers from each other.  Every
 developer works in his own directory, and CVS merges the work when each
 developer is done.

 CVS started out as a bunch of shell scripts written by Dick Grune, posted to
 the newsgroup comp.sources.unix in the volume 6 release of December, 1986.
 While no actual code from these shell scripts is present in the current
 version of CVS much of the CVS conflict resolution algorithms come from them.

 In April, 1989, Brian Berliner designed and coded CVS. Jeff Polk later helped
 Brian with the design of the CVS module and vendor branch support.

 You can get CVS in a variety of ways, including free download from the
 internet.  For more information on downloading CVS and other CVS topics, see:

                      http://www.cyclic.com/
                      http://www.loria.fr/~molli/cvs-index.html

 There is a mailing list, known as info-cvs, devoted to CVS.  To subscribe or
 unsubscribe write to [e-mail]. If you prefer a usenet group,
 the right group is comp.software.config-mgmt which is for CVS discussions
 (along with other configuration management systems).  In the future, it might
 be possible to create a comp.software.config-mgmt.cvs, but probably only if
 there is sufficient CVS traffic on comp.software.config-mgmt. You can also
 subscribe to the bug-cvs mailing list, described in more detail in BUGS.  To
 subscribe send mail to [e-mail].


ΓòÉΓòÉΓòÉ 2.2. What is CVS not? ΓòÉΓòÉΓòÉ

 CVS can do a lot of things for you, but it does not try to be everything for
 everyone.

 CVS is not a build system.
           Though the structure of your repository and modules file interact
           with your build system (e.g. 'Makefile's), they are essentially
           independent.

           CVS does not dictate how you build anything.  It merely stores files
           for retrieval in a tree structure you devise.

           CVS does not dictate how to use disk space in the checked out
           working directories.  If you write your 'Makefile's or scripts in
           every directory so they have to know the relative positions of
           everything else, you wind up requiring the entire repository to be
           checked out.

           If you modularize your work, and construct a build system that will
           share files (via links, mounts, VPATH in 'Makefile's, etc.), you can
           arrange your disk usage however you like.

           But you have to remember that any such system is a lot of work to
           construct and maintain.  CVS does not address the issues involved.

           Of course, you should place the tools created to support such a
           build system (scripts, 'Makefile's, etc) under CVS.

           Figuring out what files need to be rebuilt when something changes
           is, again, something to be handled outside the scope of CVS.  One
           traditional approach is to use make for building, and use some
           automated tool for generating the dependencies which make uses.

           See Builds, for more information on doing builds in conjunction with
           CVS.

 CVS is not a substitute for management.
           Your managers and project leaders are expected to talk to you
           frequently enough to make certain you are aware of schedules, merge
           points, branch names and release dates.  If they don't, CVS can't
           help.

           CVS is an instrument for making sources dance to your tune.  But you
           are the piper and the composer.  No instrument plays itself or
           writes its own music.

 CVS is not a substitute for developer communication.
           When faced with conflicts within a single file, most developers
           manage to resolve them without too much effort.  But a more general
           definition of ``conflict'' includes problems too difficult to solve
           without communication between developers.

           CVS cannot determine when simultaneous changes within a single file,
           or across a whole collection of files, will logically conflict with
           one another.  Its concept of a conflict is purely textual, arising
           when two changes to the same base file are near enough to spook the
           merge (i.e. diff3) command.

           CVS does not claim to help at all in figuring out non-textual or
           distributed conflicts in program logic.

           For example: Say you change the arguments to function X defined in
           file 'A'.  At the same time, someone edits file 'B', adding new
           calls to function X using the old arguments.  You are outside the
           realm of CVS's competence.

           Acquire the habit of reading specs and talking to your peers.

 CVS does not have change control
           Change control refers to a number of things.  First of all it can
           mean bug-tracking, that is being able to keep a database of reported
           bugs and the status of each one (is it fixed?  in what release?  has
           the bug submitter agreed that it is fixed?).  For interfacing CVS to
           an external bug-tracking system, see the 'rcsinfo' and 'verifymsg'
           files (see Administrative files).

           Another aspect of change control is keeping track of the fact that
           changes to several files were in fact changed together as one
           logical change.  If you check in several files in a single cvs
           commit operation, CVS then forgets that those files were checked in
           together, and the fact that they have the same log message is the
           only thing tying them together.  Keeping a GNU style 'ChangeLog' can
           help somewhat. Another aspect of change control, in some systems, is
           the ability to keep track of the status of each change.  Some
           changes have been written by a developer, others have been reviewed
           by a second developer, and so on.  Generally, the way to do this
           with CVS is to generate a diff (using cvs diff or diff) and email it
           to someone who can then apply it using the patch utility.  This is
           very flexible, but depends on mechanisms outside CVS to make sure
           nothing falls through the cracks.

 CVS is not an automated testing program
           It should be possible to enforce mandatory use of a testsuite using
           the commitinfo file.  I haven't heard a lot about projects trying to
           do that or whether there are subtle gotchas, however.

 CVS does not have a builtin process model
           Some systems provide ways to ensure that changes or releases go
           through various steps, with various approvals as needed.  Generally,
           one can accomplish this with CVS but it might be a little more work.
           In some cases you'll want to use the 'commitinfo', 'loginfo',
           'rcsinfo', or 'verifymsg' files, to require that certain steps be
           performed before cvs will allow a checkin.  Also consider whether
           features such as branches and tags can be used to perform tasks such
           as doing work in a development tree and then merging certain changes
           over to a stable tree only once they have been proven.


ΓòÉΓòÉΓòÉ 2.3. A sample session ΓòÉΓòÉΓòÉ

 As a way of introducing CVS, we'll go through a typical work-session using
 CVS.  The first thing to understand is that CVS stores all files in a
 centralized repository (see Repository); this section assumes that a
 repository is set up. Suppose you are working on a simple compiler.  The
 source consists of a handful of C files and a 'Makefile'. The compiler is
 called 'tc' (Trivial Compiler), and the repository is set up so that there is
 a module called 'tc'.

 Getting the source            Creating a workspace
 Committing your changes       Making your work available to others
 Cleaning up                   Cleaning up
 Viewing differences           Viewing differences


ΓòÉΓòÉΓòÉ 2.3.1. Getting the source ΓòÉΓòÉΓòÉ

 The first thing you must do is to get your own working copy of the source for
 'tc'.  For this, you use the checkout command:

                      $ cvs checkout tc

 This will create a new directory called 'tc' and populate it with the source
 files.

                      $ cd tc
                      $ ls
                      CVS     Makefile   backend.c  driver.c   frontend.c  parser.c

 The 'CVS' directory is used internally by CVS.  Normally, you should not
 modify or remove any of the files in it.

 You start your favorite editor, hack away at 'backend.c', and a couple of
 hours later you have added an optimization pass to the compiler. A note to RCS
 and SCCS users: There is no need to lock the files that you want to edit.  See
 Multiple developers, for an explanation.


ΓòÉΓòÉΓòÉ 2.3.2. Committing your changes ΓòÉΓòÉΓòÉ

 When you have checked that the compiler is still compilable you decide to make
 a new version of 'backend.c'.  This will store your new 'backend.c' in the
 repository and make it available to anyone else who is using that same
 repository.

                      $ cvs commit backend.c

 CVS starts an editor, to allow you to enter a log message.  You type in
 ``Added an optimization pass.'', save the temporary file, and exit the editor.

 The environment variable $CVSEDITOR determines which editor is started.  If
 $CVSEDITOR is not set, then if the environment variable $EDITOR is set, it
 will be used. If both $CVSEDITOR and $EDITOR are not set then there is a
 default which will vary with your operating system, for example vi for unix or
 notepad for Windows NT/95.

 When CVS starts the editor, it includes a list of files which are modified.
 For the CVS client, this list is based on comparing the modification time of
 the file against the modification time that the file had when it was last
 gotten or updated.  Therefore, if a file's modification time has changed but
 its contents have not, it will show up as modified.  The simplest way to
 handle this is simply not to worry about it---if you proceed with the commit
 CVS will detect that the contents are not modified and treat it as an
 unmodified file.  The next update will clue CVS in to the fact that the file
 is unmodified, and it will reset its stored timestamp so that the file will
 not show up in future editor sessions. If you want to avoid starting an editor
 you can specify the log message on the command line using the '-m' flag
 instead, like this:

                      $ cvs commit -m "Added an optimization pass" backend.c


ΓòÉΓòÉΓòÉ 2.3.3. Cleaning up ΓòÉΓòÉΓòÉ

 Before you turn to other tasks you decide to remove your working copy of tc.
 One acceptable way to do that is of course

                      $ cd ┬╖┬╖
                      $ rm -r tc

 but a better way is to use the release command (see release):

                      $ cd ┬╖┬╖
                      $ cvs release -d tc
                      M driver.c
                      ? tc
                      You have [1] altered files in this repository.
                      Are you sure you want to release (and delete) module `tc': n
                      ** `release' aborted by user choice.

 The release command checks that all your modifications have been committed.
 If history logging is enabled it also makes a note in the history file.  See
 history file.

 When you use the '-d' flag with release, it also removes your working copy.

 In the example above, the release command wrote a couple of lines of output.
 '? tc' means that the file 'tc' is unknown to CVS. That is nothing to worry
 about: 'tc' is the executable compiler, and it should not be stored in the
 repository.  See cvsignore, for information about how to make that warning go
 away. See release output, for a complete explanation of all possible output
 from release.

 'M driver.c' is more serious.  It means that the file 'driver.c' has been
 modified since it was checked out.

 The release command always finishes by telling you how many modified files you
 have in your working copy of the sources, and then asks you for confirmation
 before deleting any files or making any note in the history file.

 You decide to play it safe and answer n RET when release asks for
 confirmation.


ΓòÉΓòÉΓòÉ 2.3.4. Viewing differences ΓòÉΓòÉΓòÉ

 You do not remember modifying 'driver.c', so you want to see what has happened
 to that file.

                      $ cd tc
                      $ cvs diff driver.c

 This command runs diff to compare the version of 'driver.c' that you checked
 out with your working copy.  When you see the output you remember that you
 added a command line option that enabled the optimization pass.  You check it
 in, and release the module.

                      $ cvs commit -m "Added an optimization pass" driver.c
                      Checking in driver.c;
                      /usr/local/cvsroot/tc/driver.c,v  <--  driver.c
                      new revision: 1.2; previous revision: 1.1
                      done
                      $ cd ┬╖┬╖
                      $ cvs release -d tc
                      ? tc
                      You have [0] altered files in this repository.
                      Are you sure you want to release (and delete) module `tc': y


ΓòÉΓòÉΓòÉ 3. The Repository ΓòÉΓòÉΓòÉ

 The CVS repository stores a complete copy of all the files and directories
 which are under version control.

 Normally, you never access any of the files in the repository directly.
 Instead, you use CVS commands to get your own copy of the files into a working
 directory, and then work on that copy.  When you've finished a set of changes,
 you check (or commit) them back into the repository.  The repository then
 contains the changes which you have made, as well as recording exactly what
 you changed, when you changed it, and other such information.  Note that the
 repository is not a subdirectory of the working directory, or vice versa; they
 should be in separate locations. CVS can access a repository by a variety of
 means.  It might be on the local computer, or it might be on a computer across
 the room or across the world. To distinguish various ways to access a
 repository, the repository name can start with an access method. For example,
 the access method :local: means to access a repository directory, so the
 repository :local:/usr/local/cvsroot means that the repository is in
 '/usr/local/cvsroot' on the computer running CVS.  For information on other
 access methods, see Remote repositories.

 If the access method is omitted, then if the repository does not contain ':',
 then :local: is assumed.  If it does contain ':' then either :ext: or :server:
 is assumed.  For example, if you have a local repository in
 '/usr/local/cvsroot', you can use /usr/local/cvsroot instead of
 :local:/usr/local/cvsroot.  But if (under Windows NT, for example) your local
 repository is 'c:\src\cvsroot', then you must specify the access method, as in
 :local:c:\src\cvsroot.

 The repository is split in two parts.  '$CVSROOT/CVSROOT' contains
 administrative files for CVS.  The other directories contain the actual
 user-defined modules.

 Specifying a repository       Telling CVS where your repository is
 Repository storage            The structure of the repository
 Working directory storage     The structure of working directories
 Intro administrative files    Defining modules
 Multiple repositories         Multiple repositories
 Creating a repository         Creating a repository
 Backing up                    Backing up a repository
 Moving a repository           Moving a repository
 Remote repositories           Accessing repositories on remote machines
 Read-only access              Granting read-only access to the repository
 Server temporary directory    The server creates temporary directories


ΓòÉΓòÉΓòÉ 3.1. Telling CVS where your repository is ΓòÉΓòÉΓòÉ

 There are several ways to tell CVS where to find the repository.  You can name
 the repository on the command line explicitly, with the -d (for "directory")
 option:

                      cvs -d /usr/local/cvsroot checkout yoyodyne/tc

     Or you can set the $CVSROOT environment variable to an absolute path to
 the root of the repository, '/usr/local/cvsroot' in this example. To set
 $CVSROOT, csh and tcsh users should have this line in their '.cshrc' or
 '.tcshrc' files:

                      setenv CVSROOT /usr/local/cvsroot

 sh and bash users should instead have these lines in their '.profile' or
 '.bashrc':

                      CVSROOT=/usr/local/cvsroot
                      export CVSROOT

     A repository specified with -d will override the $CVSROOT environment
 variable. Once you've checked a working copy out from the repository, it will
 remember where its repository is (the information is recorded in the
 'CVS/Root' file in the working copy).

 The -d option and the 'CVS/Root' file both override the $CVSROOT environment
 variable.  If -d option differs from 'CVS/Root', the former is used (and
 specifying -d will cause 'CVS/Root' to be updated).  Of course, for proper
 operation they should be two ways of referring to the same repository.


ΓòÉΓòÉΓòÉ 3.2. How data is stored in the repository ΓòÉΓòÉΓòÉ

 For most purposes it isn't important how CVS stores information in the
 repository.  In fact, the format has changed in the past, and is likely to
 change in the future.  Since in almost all cases one accesses the repository
 via CVS commands, such changes need not be disruptive.

 However, in some cases it may be necessary to understand how CVS stores data
 in the repository, for example you might need to track down CVS locks (see
 Concurrency) or you might need to deal with the file permissions appropriate
 for the repository.

 Repository files              What files are stored in the repository
 File permissions              File permissions
 Windows permissions           Issues specific to Windows
 Attic                         Some files are stored in the Attic
 CVS in repository             Additional information in CVS directory
 Locks                         CVS locks control concurrent accesses
 CVSROOT storage               A few things about CVSROOT are different


ΓòÉΓòÉΓòÉ 3.2.1. Where files are stored within the repository ΓòÉΓòÉΓòÉ

 The overall structure of the repository is a directory tree corresponding to
 the directories in the working directory.  For example, supposing the
 repository is in

                      /usr/local/cvsroot

 here is a possible directory tree (showing only the directories):

                      /usr
                       |
                       +--local
                       |  |
                       |  +--cvsroot
                       |  |   |
                       |  |   +--CVSROOT
                           |    (administrative files)
                           |
                           +--gnu
                           |  |
                           |  +--diff
                           |  |  (source code to GNU diff)
                           |  |
                           |  +--rcs
                           |  |  (source code to RCS)
                           |  |
                           |  +--cvs
                           |    (source code to CVS)
                           |
                           +--yoyodyne
                             |
                             +--tc
                             |   |
                             |   +--man
                             |   |
                             |   +--testing
                             |
                             +--(other Yoyodyne software)

 With the directories are history files for each file under version control.
 The name of the history file is the name of the corresponding file with ',v'
 appended to the end.  Here is what the repository for the 'yoyodyne/tc'
 directory might look like:

                       $CVSROOT
                        |
                        +--yoyodyne
                        |  |
                        |  +--tc
                        |  |  |
                            +--Makefile,v
                            +--backend.c,v
                            +--driver.c,v
                            +--frontend.c,v
                            +--parser.c,v
                            +--man
                            |   |
                            |   +--tc.1,v
                            |
                            +--testing
                               |
                               +--testpgm.t,v
                               +--test2.t,v

 The history files contain, among other things, enough information to recreate
 any revision of the file, a log of all commit messages and the user-name of
 the person who committed the revision.  The history files are known as RCS
 files, because the first program to store files in that format was a version
 control system known as RCS.  For a full description of the file format, see
 the man page rcsfile(5), distributed with RCS, or the file 'doc/RCSFILES' in
 the CVS source distribution.  This file format has become very common---many
 systems other than CVS or RCS can at least import history files in this
 format. The RCS files used in CVS differ in a few ways from the standard
 format.  The biggest difference is magic branches; for more information see
 Magic branch numbers.  Also in CVS the valid tag names are a subset of what
 RCS accepts; for CVS's rules see Tags.


ΓòÉΓòÉΓòÉ 3.2.2. File permissions ΓòÉΓòÉΓòÉ

 All ',v' files are created read-only, and you should not change the permission
 of those files.  The directories inside the repository should be writable by
 the persons that have permission to modify the files in each directory.  This
 normally means that you must create a UNIX group (see group(5)) consisting of
 the persons that are to edit the files in a project, and set up the repository
 so that it is that group that owns the directory. This means that you can only
 control access to files on a per-directory basis.

 Note that users must also have write access to check out files, because CVS
 needs to create lock files (see Concurrency).

 Also note that users must have write access to the 'CVSROOT/val-tags' file.
 CVS uses it to keep track of what tags are valid tag names (it is sometimes
 updated when tags are used, as well as when they are created).

 Each RCS file will be owned by the user who last checked it in.  This has
 little significance; what really matters is who owns the directories.

 CVS tries to set up reasonable file permissions for new directories that are
 added inside the tree, but you must fix the permissions manually when a new
 directory should have different permissions than its parent directory.  If you
 set the CVSUMASK environment variable that will control the file permissions
 which CVS uses in creating directories and/or files in the repository.
 CVSUMASK does not affect the file permissions in the working directory; such
 files have the permissions which are typical for newly created files, except
 that sometimes CVS creates them read-only (see the sections on watches,
 Setting a watch; -r, Global options; or CVSREAD, Environment variables). Note
 that using the client/server CVS (see Remote repositories), there is no good
 way to set CVSUMASK; the setting on the client machine has no effect.  If you
 are connecting with rsh, you can set CVSUMASK in '.bashrc' or '.cshrc', as
 described in the documentation for your operating system.  This behavior might
 change in future versions of CVS; do not rely on the setting of CVSUMASK on
 the client having no effect. Using pserver, you will generally need stricter
 permissions on the CVSROOT directory and directories above it in the tree; see
 Password authentication security.

 Some operating systems have features which allow a particular program to run
 with the ability to perform operations which the caller of the program could
 not. For example, the set user ID (setuid) or set group ID (setgid) features
 of unix or the installed image feature of VMS.  CVS was not written to use
 such features and therefore attempting to install CVS in this fashion will
 provide protection against only accidental lapses; anyone who is trying to
 circumvent the measure will be able to do so, and depending on how you have
 set it up may gain access to more than just CVS.  You may wish to instead
 consider pserver.  It shares some of the same attributes, in terms of possibly
 providing a false sense of security or opening security holes wider than the
 ones you are trying to fix, so read the documentation on pserver security
 carefully if you are considering this option (Password authentication
 security).


ΓòÉΓòÉΓòÉ 3.2.3. File Permission issues specific to Windows ΓòÉΓòÉΓòÉ

 Some file permission issues are specific to Windows operating systems (Windows
 95, Windows NT, and presumably future operating systems in this family. Some
 of the following might apply to OS/2 but I'm not sure).

 If you are using local CVS and the repository is on a networked file system
 which is served by the Samba SMB server, some people have reported problems
 with permissions.  Enabling WRITE=YES in the samba configuration is said to
 fix/workaround it. Disclaimer: I haven't investigated enough to know the
 implications of enabling that option, nor do I know whether there is something
 which CVS could be doing differently in order to avoid the problem.  If you
 find something out, please let us know as described in BUGS.


ΓòÉΓòÉΓòÉ 3.2.4. The attic ΓòÉΓòÉΓòÉ

 You will notice that sometimes CVS stores an RCS file in the Attic.  For
 example, if the CVSROOT is '/usr/local/cvsroot' and we are talking about the
 file 'backend.c' in the directory 'yoyodyne/tc', then the file normally would
 be in

                      /usr/local/cvsroot/yoyodyne/tc/backend.c,v

 but if it goes in the attic, it would be in

                      /usr/local/cvsroot/yoyodyne/tc/Attic/backend.c,v

 instead.  It should not matter from a user point of view whether a file is in
 the attic; CVS keeps track of this and looks in the attic when it needs to.
 But in case you want to know, the rule is that the RCS file is stored in the
 attic if and only if the head revision on the trunk has state dead.  A dead
 state means that file has been removed, or never added, for that revision.
 For example, if you add a file on a branch, it will have a trunk revision in
 dead state, and a branch revision in a non-dead state.


ΓòÉΓòÉΓòÉ 3.2.5. The CVS directory in the repository ΓòÉΓòÉΓòÉ

 The 'CVS' directory in each repository directory contains information such as
 file attributes (in a file called 'CVS/fileattr'; see fileattr.h in the CVS
 source distribution for more documentation).  In the future additional files
 may be added to this directory, so implementations should silently ignore
 additional files.

 This behavior is implemented only by CVS 1.7 and later; for details see
 Watches Compatibility.


ΓòÉΓòÉΓòÉ 3.2.6. CVS locks in the repository ΓòÉΓòÉΓòÉ

 For an introduction to CVS locks focusing on user-visible behavior, see
 Concurrency.  The following section is aimed at people who are writing tools
 which want to access a CVS repository without interfering with other tools
 acessing the same repository.  If you find yourself confused by concepts
 described here, like read lock, write lock, and deadlock, you might consult
 the literature on operating systems or databases.

 Any file in the repository with a name starting with '#cvs.rfl' is a read
 lock.  Any file in the repository with a name starting with '#cvs.wfl' is a
 write lock.  Old versions of CVS (before CVS 1.5) also created files with
 names starting with '#cvs.tfl', but they are not discussed here. The directory
 '#cvs.lock' serves as a master lock.  That is, one must obtain this lock first
 before creating any of the other locks.

 To obtain a readlock, first create the '#cvs.lock' directory.  This operation
 must be atomic (which should be true for creating a directory under most
 operating systems).  If it fails because the directory already existed, wait
 for a while and try again.  After obtaining the '#cvs.lock' lock, create a
 file whose name is '#cvs.rfl' followed by information of your choice (for
 example, hostname and process identification number).  Then remove the
 '#cvs.lock' directory to release the master lock. Then proceed with reading
 the repository.  When you are done, remove the '#cvs.rfl' file to release the
 read lock.

 To obtain a writelock, first create the '#cvs.lock' directory, as with a
 readlock.  Then check that there are no files whose names start with
 '#cvs.rfl'.  If there are, remove '#cvs.lock', wait for a while, and try
 again.  If there are no readers, then create a file whose name is '#cvs.wfl'
 followed by information of your choice (for example, hostname and process
 identification number).  Hang on to the '#cvs.lock' lock.  Proceed with
 writing the repository.  When you are done, first remove the '#cvs.wfl' file
 and then the '#cvs.lock' directory. Note that unlike the '#cvs.rfl' file, the
 '#cvs.wfl' file is just informational; it has no effect on the locking
 operation beyond what is provided by holding on to the '#cvs.lock' lock
 itself.

 Note that each lock (writelock or readlock) only locks a single directory in
 the repository, including 'Attic' and 'CVS' but not including subdirectories
 which represent other directories under version control.  To lock an entire
 tree, you need to lock each directory (note that if you fail to obtain any
 lock you need, you must release the whole tree before waiting and trying
 again, to avoid deadlocks).

 Note also that CVS expects writelocks to control access to individual 'foo,v'
 files.  RCS has a scheme where the ',foo,' file serves as a lock, but CVS does
 not implement it and so taking out a CVS writelock is recommended.  See the
 comments at rcs_internal_lockfile in the CVS source code for further
 discussion/rationale.


ΓòÉΓòÉΓòÉ 3.2.7. How files are stored in the CVSROOT directory ΓòÉΓòÉΓòÉ

 The '$CVSROOT/CVSROOT' directory contains the various administrative files.
 In some ways this directory is just like any other directory in the
 repository; it contains RCS files whose names end in ',v', and many of the CVS
 commands operate on it the same way.  However, there are a few differences.

 For each administrative file, in addition to the RCS file, there is also a
 checked out copy of the file.  For example, there is an RCS file 'loginfo,v'
 and a file 'loginfo' which contains the latest revision contained in
 'loginfo,v'.  When you check in an administrative file, CVS should print

                      cvs commit: Rebuilding administrative file database

 and update the checked out copy in '$CVSROOT/CVSROOT'.  If it does not, there
 is something wrong (see BUGS).  To add your own files to the files to be
 updated in this fashion, you can add them to the 'checkoutlist' administrative
 file. By default, the 'modules' file behaves as described above.  If the
 modules file is very large, storing it as a flat text file may make looking up
 modules slow (I'm not sure whether this is as much of a concern now as when
 CVS first evolved this feature; I haven't seen benchmarks).  Therefore, by
 making appropriate edits to the CVS source code one can store the modules file
 in a database which implements the ndbm interface, such as Berkeley db or
 GDBM.  If this option is in use, then the modules database will be stored in
 the files 'modules.db', 'modules.pag', and/or 'modules.dir'. For information
 on the meaning of the various administrative files, see Administrative files.


ΓòÉΓòÉΓòÉ 3.3. How data is stored in the working directory ΓòÉΓòÉΓòÉ

 While we are discussing CVS internals which may become visible from time to
 time, we might as well talk about what CVS puts in the 'CVS' directories in
 the working directories.  As with the repository, CVS handles this information
 and one can usually access it via CVS commands.  But in some cases it may be
 useful to look at it, and other programs, such as the jCVS graphical user
 interface or the VC package for emacs, may need to look at it. Such programs
 should follow the recommendations in this section if they hope to be able to
 work with other programs which use those files, including future versions of
 the programs just mentioned and the command-line CVS client.

 The 'CVS' directory contains several files. Programs which are reading this
 directory should silently ignore files which are in the directory but which
 are not documented here, to allow for future expansion.

 Root
           This file contains the current CVS root, as described in Specifying
           a repository.

 Repository
           This file contains the directory within the repository which the
           current directory corresponds with.  It can be either an absolute
           pathname or a relative pathname; CVS has had the ability to read
           either format since at least version 1.3 or so.  The relative
           pathname is relative to the root, and is the more sensible approach,
           but the absolute pathname is quite common and implementations should
           accept either.  For example, after the command

                      cvs -d :local:/usr/local/cvsroot checkout yoyodyne/tc

 'Root' will contain

                      :local:/usr/local/cvsroot

 and 'Repository' will contain either

                      /usr/local/cvsroot/yoyodyne/tc

 or

                      yoyodyne/tc

 Entries
           This file lists the files and directories in the working directory.
           It is a text file according to the conventions appropriate for the
           operating system in question. The first character of each line
           indicates what sort of line it is.  If the character is
           unrecognized, programs reading the file should silently skip that
           line, to allow for future expansion.

           If the first character is '/', then the format is:

                      /name/revision/timestamp[+conflict]/options/tagdate

 where '[' and ']' are not part of the entry, but instead indicate that the '+'
 and conflict marker are optional.  name is the name of the file within the
 directory.  revision is the revision that the file in the working derives
 from, or '0' for an added file, or '-' followed by a revision for a removed
 file.  timestamp is the timestamp of the file at the time that CVS created it;
 if the timestamp differs with the actual modification time of the file it
 means the file has been modified.  It is in Universal Time (UT), stored in the
 format used by the ISO C asctime() function (for example, 'Sun Apr  7 01:29:26
 1996').  One may write a string which is not in that format, for example,
 'Result of merge', to indicate that the file should always be considered to be
 modified.  This is not a special case; to see whether a file is modified a
 program should take the timestamp of the file and simply do a string compare
 with timestamp. conflict indicates that there was a conflict; if it is the
 same as the actual modification time of the file it means that the user has
 obviously not resolved the conflict.  options contains sticky options (for
 example '-kb' for a binary file).  tagdate contains 'T' followed by a tag
 name, or 'D' for a date, followed by a sticky tag or date.  Note that if
 timestamp contains a pair of timestamps separated by a space, rather than a
 single timestamp, you are dealing with a version of CVS earlier than CVS 1.5
 (not documented here).

 If the first character of a line in 'Entries' is 'D', then it indicates a
 subdirectory.  'D' on a line all by itself indicates that the program which
 wrote the 'Entries' file does record subdirectories (therefore, if there is
 such a line and no other lines beginning with 'D', one knows there are no
 subdirectories).  Otherwise, the line looks like:

                      D/name/filler1/filler2/filler3/filler4

 where name is the name of the subdirectory, and all the filler fields should
 be silently ignored, for future expansion.  Programs which modify Entries
 files should preserve these fields.

 Entries.Log
           This file does not record any information beyond that in 'Entries',
           but it does provide a way to update the information without having
           to rewrite the entire 'Entries' file, including the ability to
           preserve the information even if the program writing 'Entries' and
           'Entries.Log' abruptly aborts. Programs which are reading the
           'Entries' file should also check for 'Entries.Log'.  If the latter
           exists, they should read 'Entries' and then apply the changes
           mentioned in 'Entries.Log'.  After applying the changes, the
           recommended practice is to rewrite 'Entries' and then delete
           'Entries.Log'. The format of a line in 'Entries.Log' is a single
           character command followed by a space followed by a line in the
           format specified for a line in 'Entries'.  The single character
           command is 'A' to indicate that the entry is being added, 'R' to
           indicate that the entry is being removed, or any other character to
           indicate that the entire line in 'Entries.Log' should be silently
           ignored (for future expansion).  If the second character of the line
           in 'Entries.Log' is not a space, then it was written by an older
           version of CVS (not documented here).

 Entries.Backup
           This is a temporary file.  Recommended usage is to write a new
           entries file to 'Entries.Backup', and then to rename it (atomically,
           where possible) to 'Entries'.

 Entries.Static
           The only relevant thing about this file is whether it exists or not.
           If it exists, then it means that only part of a directory was gotten
           and CVS will not create additional files in that directory.  To
           clear it, use the update command with the '-d' option, which will
           get the additional files and remove 'Entries.Static'.

 Tag
           This file contains per-directory sticky tags or dates. The first
           character is 'T' for a branch tag, 'N' for a non-branch tag, or 'D'
           for a date, or another character to mean the file should be silently
           ignored, for future expansion.  This character is followed by the
           tag or date.  Note that per-directory sticky tags or dates are used
           for things like applying to files which are newly added; they might
           not be the same as the sticky tags or dates on individual files.
           For general information on sticky tags and dates, see Sticky tags.

 Checkin.prog

 Update.prog
           These files store the programs specified by the '-i' and '-u'
           options in the modules file, respectively.

 Notify
           This file stores notifications (for example, for edit or unedit)
           which have not yet been sent to the server.  Its format is not yet
           documented here.

 Notify.tmp
           This file is to 'Notify' as 'Entries.Backup' is to 'Entries'.  That
           is, to write 'Notify', first write the new contents to 'Notify.tmp'
           and then (atomically where possible), rename it to 'Notify'.

 Base
           If watches are in use, then an edit command stores the original copy
           of the file in the 'Base' directory.  This allows the unedit command
           to operate even if it is unable to communicate with the server.

 Baserev
           The file lists the revision for each of the files in the 'Base'
           directory.  The format is:

                      Bname/rev/expansion

 where expansion should be ignored, to allow for future expansion.

 Baserev.tmp
           This file is to 'Baserev' as 'Entries.Backup' is to 'Entries'.  That
           is, to write 'Baserev', first write the new contents to
           'Baserev.tmp' and then (atomically where possible), rename it to
           'Baserev'.

 Template
           This file contains the template specified by the 'rcsinfo' file (see
           rcsinfo).  It is only used by the client; the non-client/server CVS
           consults 'rcsinfo' directly.


ΓòÉΓòÉΓòÉ 3.4. The administrative files ΓòÉΓòÉΓòÉ

 The directory '$CVSROOT/CVSROOT' contains some administrative files.  See
 Administrative files, for a complete description. You can use CVS without any
 of these files, but some commands work better when at least the 'modules' file
 is properly set up.

 The most important of these files is the 'modules' file.  It defines all
 modules in the repository.  This is a sample 'modules' file.

                      CVSROOT     CVSROOT
                      modules     CVSROOT modules
                      cvs       gnu/cvs
                      rcs       gnu/rcs
                      diff       gnu/diff
                      tc        yoyodyne/tc

 The 'modules' file is line oriented.  In its simplest form each line contains
 the name of the module, whitespace, and the directory where the module
 resides.  The directory is a path relative to $CVSROOT.  The last four lines
 in the example above are examples of such lines.

 The line that defines the module called 'modules' uses features that are not
 explained here. See modules, for a full explanation of all the available
 features.


ΓòÉΓòÉΓòÉ 3.4.1. Editing administrative files ΓòÉΓòÉΓòÉ

 You edit the administrative files in the same way that you would edit any
 other module.  Use 'cvs checkout CVSROOT' to get a working copy, edit it, and
 commit your changes in the normal way.

 It is possible to commit an erroneous administrative file.  You can often fix
 the error and check in a new revision, but sometimes a particularly bad error
 in the administrative file makes it impossible to commit new revisions.


ΓòÉΓòÉΓòÉ 3.5. Multiple repositories ΓòÉΓòÉΓòÉ

 In some situations it is a good idea to have more than one repository, for
 instance if you have two development groups that work on separate projects
 without sharing any code.  All you have to do to have several repositories is
 to specify the appropriate repository, using the CVSROOT environment variable,
 the '-d' option to CVS, or (once you have checked out a working directory) by
 simply allowing CVS to use the repository that was used to check out the
 working directory (see Specifying a repository).

 The big advantage of having multiple repositories is that they can reside on
 different servers.  The big disadvantage is that you cannot have a single CVS
 command recurse into directories which comes from different repositories.
 Generally speaking, if you are thinking of setting up several repositories on
 the same machine, you might want to consider using several directories within
 the same repository. None of the examples in this manual show multiple
 repositories.


ΓòÉΓòÉΓòÉ 3.6. Creating a repository ΓòÉΓòÉΓòÉ

 To set up a CVS repository, first choose the machine and disk on which you
 want to store the revision history of the source files.  CPU and memory
 requirements are modest, so most machines should be adequate.  For details see
 Server requirements. To estimate disk space requirements, if you are importing
 RCS files from another system, the size of those files is the approximate
 initial size of your repository, or if you are starting without any version
 history, a rule of thumb is to allow for the server approximately three times
 the size of the code to be under CVS for the repository (you will eventually
 outgrow this, but not for a while).  On the machines on which the developers
 will be working, you'll want disk space for approximately one working
 directory for each developer (either the entire tree or a portion of it,
 depending on what each developer uses).

 The repository should be accessable (directly or via a networked file system)
 from all machines which want to use CVS in server or local mode; the client
 machines need not have any access to it other than via the CVS protocol.  It
 is not possible to use CVS to read from a repository which one only has read
 access to; CVS needs to be able to create lock files (see Concurrency).

 To create a repository, run the cvs init command.  It will set up an empty
 repository in the CVS root specified in the usual way (see Repository).  For
 example,

                      cvs -d /usr/local/cvsroot init

 cvs init is careful to never overwrite any existing files in the repository,
 so no harm is done if you run cvs init on an already set-up repository.

 cvs init will enable history logging; if you don't want that, remove the
 history file after running cvs init.  See history file.


ΓòÉΓòÉΓòÉ 3.7. Backing up a repository ΓòÉΓòÉΓòÉ

 There is nothing particularly magical about the files in the repository; for
 the most part it is possible to back them up just like any other files.
 However, there are a few issues to consider.

 The first is that to be paranoid, one should either not use CVS during the
 backup, or have the backup program lock CVS while doing the backup.  To not
 use CVS, you might forbid logins to machines which can access the repository,
 turn off your CVS server, or similar mechanisms.  The details would depend on
 your operating system and how you have CVS set up.  To lock CVS, you would
 create '#cvs.rfl' locks in each repository directory. See Concurrency, for
 more on CVS locks. Having said all this, if you just back up without any of
 these precautions, the results are unlikely to be particularly dire.
 Restoring from backup, the repository might be in an inconsistent state, but
 this would not be particularly hard to fix manually.

 When you restore a repository from backup, assuming that changes in the
 repository were made after the time of the backup, working directories which
 were not affected by the failure may refer to revisions which no longer exist
 in the repository.  Trying to run CVS in such directories will typically
 produce an error message.  One way to get those changes back into the
 repository is as follows:

     Get a new working directory.

     Copy the files from the working directory from before the failure over to
      the new working directory (do not copy the contents of the 'CVS'
      directories, of course).

     Working in the new working directory, use commands such as cvs update and
      cvs diff to figure out what has changed, and then when you are ready,
      commit the changes into the repository.


ΓòÉΓòÉΓòÉ 3.8. Moving a repository ΓòÉΓòÉΓòÉ

 Just as backing up the files in the repository is pretty much like backing up
 any other files, if you need to move a repository from one place to another it
 is also pretty much like just moving any other collection of files.

 The main thing to consider is that working directories point to the
 repository.  The simplest way to deal with a moved repository is to just get a
 fresh working directory after the move.  Of course, you'll want to make sure
 that the old working directory had been checked in before the move, or you
 figured out some other way to make sure that you don't lose any changes.  If
 you really do want to reuse the existing working directory, it should be
 possible with manual surgery on the 'CVS/Repository' files.  You can see
 Working directory storage, for information on the 'CVS/Repository' and
 'CVS/Root' files, but unless you are sure you want to bother, it probably
 isn't worth it.


ΓòÉΓòÉΓòÉ 3.9. Remote repositories ΓòÉΓòÉΓòÉ

     Your working copy of the sources can be on a different machine than the
 repository.  Using CVS in this manner is known as client/server operation.
 You run CVS on a machine which can mount your working directory, known as the
 client, and tell it to communicate to a machine which can mount the
 repository, known as the server.  Generally, using a remote repository is just
 like using a local one, except that the format of the repository name is:

                      :method:user@hostname:/path/to/repository

 The details of exactly what needs to be set up depend on how you are
 connecting to the server.

 If method is not specified, and the repository name contains ':', then the
 default is ext or server, depending on your platform; both are described in
 Connecting via rsh.

 Server requirements           Memory and other resources for servers
 Connecting via rsh            Using the rsh program to connect
 Password authenticated        Direct connections using passwords
 GSSAPI authenticated          Direct connections using GSSAPI
 Kerberos authenticated        Direct connections with kerberos


ΓòÉΓòÉΓòÉ 3.9.1. Server requirements ΓòÉΓòÉΓòÉ

 The quick answer to what sort of machine is suitable as a server is that
 requirements are modest---a server with 32M of memory or even less can handle
 a fairly large source tree with a fair amount of activity. The real answer, of
 course, is more complicated. Estimating the known areas of large memory
 consumption should be sufficient to estimate memory requirements. There are
 two such areas documented here; other memory consumption should be small by
 comparison (if you find that is not the case, let us know, as described in
 BUGS, so we can update this documentation).

 The first area of big memory consumption is large checkouts, when using the
 CVS server.  The server consists of two processes for each client that it is
 serving.  Memory consumption on the child process should remain fairly small.
 Memory consumption on the parent process, particularly if the network
 connection to the client is slow, can be expected to grow to slightly more
 than the size of the sources in a single directory, or two megabytes,
 whichever is larger. Multiplying the size of each CVS server by the number of
 servers which you expect to have active at one time should give an idea of
 memory requirements for the server.  For the most part, the memory consumed by
 the parent process probably can be swap space rather than physical memory. The
 second area of large memory consumption is diff, when checking in large files.
 This is required even for binary files.  The rule of thumb is to allow about
 ten times the size of the largest file you will want to check in, although
 five times may be adequate.  For example, if you want to check in a file which
 is 10 megabytes, you should have 100 megabytes of memory on the machine doing
 the checkin (the server machine for client/server, or the machine running CVS
 for non-client/server).  This can be swap space rather than physical memory.
 Because the memory is only required briefly, there is no particular need to
 allow memory for more than one such checkin at a time. Resource consumption
 for the client is even more modest---any machine with enough capacity to run
 the operating system in question should have little trouble. For information
 on disk space requirements, see Creating a repository.


ΓòÉΓòÉΓòÉ 3.9.2. Connecting with rsh ΓòÉΓòÉΓòÉ

 CVS uses the 'rsh' protocol to perform these operations, so the remote user
 host needs to have a '.rhosts' file which grants access to the local user.

 For example, suppose you are the user 'mozart' on the local machine
 'toe.grunge.com', and the server machine is 'chainsaw.yard.com'.  On chainsaw,
 put the following line into the file '.rhosts' in 'bach''s home directory:

                      toe.grunge.com  mozart

 Then test that rsh is working with

                      rsh -l bach chainsaw.yard.com 'echo $PATH'

 Next you have to make sure that rsh will be able to find the server.  Make
 sure that the path which rsh printed in the above example includes the
 directory containing a program named cvs which is the server.  You need to set
 the path in '.bashrc', '.cshrc', etc., not '.login' or '.profile'.
 Alternately, you can set the environment variable CVS_SERVER on the client
 machine to the filename of the server you want to use, for example
 '/usr/local/bin/cvs-1.6'. There is no need to edit inetd.conf or start a CVS
 server daemon.

 There are two access methods that you use in CVSROOT for rsh.  :server:
 specifies an internal rsh client, which is supported only by some CVS ports.
 :ext: specifies an external rsh program.  By default this is rsh but you may
 set the CVS_RSH environment variable to invoke another program which can
 access the remote server (for example, remsh on HP-UX 9 because rsh is
 something different).  It must be a program which can transmit data to and
 from the server without modifying it; for example the Windows NT rsh is not
 suitable since it by default translates between CRLF and LF.  The OS/2 CVS
 port has a hack to pass '-b' to rsh to get around this, but since this could
 potentially cause problems for programs other than the standard rsh, it may
 change in the future.  If you set CVS_RSH to SSH or some other rsh
 replacement, the instructions in the rest of this section concerning '.rhosts'
 and so on are likely to be inapplicable; consult the documentation for your
 rsh replacement. Continuing our example, supposing you want to access the
 module 'foo' in the repository '/usr/local/cvsroot/', on machine
 'chainsaw.yard.com', you are ready to go:

                      cvs -d :ext:[e-mail]:/usr/local/cvsroot checkout foo

 (The 'bach@' can be omitted if the username is the same on both the local and
 remote hosts.)


ΓòÉΓòÉΓòÉ 3.9.3. Direct connection with password authentication ΓòÉΓòÉΓòÉ

 The CVS client can also connect to the server using a password protocol.  This
 is particularly useful if using rsh is not feasible (for example, the server
 is behind a firewall), and Kerberos also is not available.

     To use this method, it is necessary to make some adjustments on both the
 server and client sides.

 Password authentication serverSetting up the server
 Password authentication clientUsing the client
 Password authentication securityWhat this method does and does not do


ΓòÉΓòÉΓòÉ 3.9.3.1. Setting up the server for password authentication ΓòÉΓòÉΓòÉ

 First of all, you probably want to tighten the permissions on the '$CVSROOT'
 and '$CVSROOT/CVSROOT' directories.  See Password authentication security, for
 more details.

 On the server side, the file '/etc/inetd.conf' needs to be edited so inetd
 knows to run the command cvs pserver when it receives a connection on the
 right port.  By default, the port number is 2401; it would be different if
 your client were compiled with CVS_AUTH_PORT defined to something else,
 though.

     If your inetd allows raw port numbers in '/etc/inetd.conf', then the
 following (all on a single line in 'inetd.conf') should be sufficient:

                      2401  stream  tcp  nowait  root  /usr/local/bin/cvs
                      cvs --allow-root=/usr/cvsroot pserver

 You could also use the '-T' option to specify a temporary directory.

 The '--allow-root' option specifies the allowable CVSROOT directory.  Clients
 which attempt to use a different CVSROOT directory will not be allowed to
 connect.  If there is more than one CVSROOT directory which you want to allow,
 repeat the option.

     If your inetd wants a symbolic service name instead of a raw port number,
 then put this in '/etc/services':

                      cvspserver    2401/tcp

     and put cvspserver instead of 2401 in 'inetd.conf'.

     Once the above is taken care of, restart your inetd, or do whatever is
 necessary to force it to reread its initialization files.

 Because the client stores and transmits passwords in cleartext (almost---see
 Password authentication security, for details), a separate CVS password file
 may be used, so people don't compromise their regular passwords when they
 access the repository. This file is '$CVSROOT/CVSROOT/passwd' (see Intro
 administrative files).  Its format is similar to '/etc/passwd', except that it
 only has two or three fields, username, password, and optional username for
 the server to use.  For example:

                      bach:ULtgRLXo7NRxs
                      cwang:1sOp854gDF3DY

 The password is encrypted according to the standard Unix crypt() function, so
 it is possible to paste in passwords directly from regular Unix 'passwd'
 files.

 When authenticating a password, the server first checks for the user in the
 CVS 'passwd' file.  If it finds the user, it compares against that password.
 If it does not find the user, or if the CVS 'passwd' file does not exist, then
 the server tries to match the password using the system's user-lookup routine
 (using the system's user-lookup routine can be disabled by setting
 SystemAuth=no in the config file, see config).  When using the CVS 'passwd'
 file, the server runs as the username specified in the third argument in the
 entry, or as the first argument if there is no third argument (in this way CVS
 allows imaginary usernames provided the CVS 'passwd' file indicates
 corresponding valid system usernames).  In any case, CVS will have no
 privileges which the (valid) user would not have.

     It is possible to ``map'' cvs-specific usernames onto system usernames
 (i.e., onto system login names) in the '$CVSROOT/CVSROOT/passwd' file by
 appending a colon and the system username after the password.  For example:

                      cvs:ULtgRLXo7NRxs:kfogel
                      generic:1sOp854gDF3DY:spwang
                      anyone:1sOp854gDF3DY:spwang

     Thus, someone remotely accessing the repository on 'chainsaw.yard.com'
 with the following command:

                      cvs -d :pserver:[e-mail]:/usr/local/cvsroot checkout foo

     would end up running the server under the system identity kfogel, assuming
 successful authentication.  However, the remote user would not necessarily
 need to know kfogel's system password, as the '$CVSROOT/CVSROOT/passwd' file
 might contain a different password, used only for CVS.  And as the example
 above indicates, it is permissible to map multiple cvs usernames onto a single
 system username.

     This feature is designed to allow people repository access without full
 system access (in particular, see Read-only access); however, also see
 Password authentication security.  Any sort of repository access very likely
 implies a degree of general system access as well.

 Right now, the only way to put a password in the CVS 'passwd' file is to paste
 it there from somewhere else.  Someday, there may be a cvs passwd command.


ΓòÉΓòÉΓòÉ 3.9.3.2. Using the client with password authentication ΓòÉΓòÉΓòÉ

 Before connecting to the server, the client must log in with the command cvs
 login.  Logging in verifies a password with the server, and also records the
 password for later transactions with the server. The cvs login command needs
 to know the username, server hostname, and full repository path, and it gets
 this information from the repository argument or the CVSROOT environment
 variable.

 cvs login is interactive --- it prompts for a password:

                      cvs -d :pserver:[e-mail]:/usr/local/cvsroot login
                      CVS password:

 The password is checked with the server; if it is correct, the login succeeds,
 else it fails, complaining that the password was incorrect.

 Once you have logged in, you can force CVS to connect directly to the server
 and authenticate with the stored password:

                      cvs -d :pserver:[e-mail]:/usr/local/cvsroot checkout foo

 The ':pserver:' is necessary because without it, CVS will assume it should use
 rsh to connect with the server (see Connecting via rsh). (Once you have a
 working copy checked out and are running CVS commands from within it, there is
 no longer any need to specify the repository explicitly, because CVS records
 it in the working copy's 'CVS' subdirectory.)

 Passwords are stored by default in the file '$HOME/.cvspass'.  Its format is
 human-readable, but don't edit it unless you know what you are doing. The
 passwords are not stored in cleartext, but are trivially encoded to protect
 them from "innocent" compromise (i.e., inadvertently being seen by a system
 administrator who happens to look at that file).

 The password for the currently choosen remote repository can be removed from
 the CVS_PASSFILE by using the cvs logout command.

 The CVS_PASSFILE environment variable overrides this default.  If you use this
 variable, make sure you set it before cvs login is run.  If you were to set it
 after running cvs login, then later CVS commands would be unable to look up
 the password for transmission to the server.


ΓòÉΓòÉΓòÉ 3.9.3.3. Security considerations with password authentication ΓòÉΓòÉΓòÉ

 The passwords are stored on the client side in a trivial encoding of the
 cleartext, and transmitted in the same encoding.  The encoding is done only to
 prevent inadvertent password compromises (i.e., a system administrator
 accidentally looking at the file), and will not prevent even a naive attacker
 from gaining the password.

 The separate CVS password file (see Password authentication server) allows
 people to use a different password for repository access than for login
 access.  On the other hand, once a user has non-read-only access to the
 repository, she can execute programs on the server system through a variety of
 means.  Thus, repository access implies fairly broad system access as well.
 It might be possible to modify CVS to prevent that, but no one has done so as
 of this writing. Furthermore, there may be other ways in which having access
 to CVS allows people to gain more general access to the system; no one has
 done a careful audit.

 Note that because the '$CVSROOT/CVSROOT' directory contains 'passwd' and other
 files which are used to check security, you must control the permissions on
 this directory as tightly as the permissions on '/etc'.  The same applies to
 the '$CVSROOT' directory itself and any directory above it in the tree.
 Anyone who has write access to such a directory will have the ability to
 become any user on the system.  Note that these permissions are typically
 tighter than you would use if you are not using pserver. In summary, anyone
 who gets the password gets repository access, and some measure of general
 system access as well.  The password is available to anyone who can sniff
 network packets or read a protected (i.e., user read-only) file.  If you want
 real security, get Kerberos.


ΓòÉΓòÉΓòÉ 3.9.4. Direct connection with GSSAPI ΓòÉΓòÉΓòÉ

 GSSAPI is a generic interface to network security systems such as Kerberos 5.
 If you have a working GSSAPI library, you can have CVS connect via a direct
 TCP connection, authenticating with GSSAPI.

 To do this, CVS needs to be compiled with GSSAPI support; when configuring CVS
 it tries to detect whether GSSAPI libraries using kerberos version 5 are
 present.  You can also use the '--with-gssapi' flag to configure.

 The connection is authenticated using GSSAPI, but the message stream is not
 authenticated by default. You must use the -a global option to request stream
 authentication.

 The data transmitted is not encrypted by default.  Encryption support must be
 compiled into both the client and the server; use the '--enable-encrypt'
 configure option to turn it on. You must then use the -x global option to
 request encryption.

 GSSAPI connections are handled on the server side by the same server which
 handles the password authentication server; see Password authentication
 server.  If you are using a GSSAPI mechanism such as Kerberos which provides
 for strong authentication, you will probably want to disable the ability to
 authenticate via cleartext passwords.  To do so, create an empty
 'CVSROOT/passwd' password file, and set SystemAuth=no in the config file (see
 config).

 The GSSAPI server uses a principal name of cvs/hostname, where hostname is the
 canonical name of the server host.  You will have to set this up as required
 by your GSSAPI mechanism.

 To connect using GSSAPI, use ':gserver:'.  For example,

                      cvs -d :gserver:chainsaw.yard.com:/usr/local/cvsroot checkout foo


ΓòÉΓòÉΓòÉ 3.9.5. Direct connection with kerberos ΓòÉΓòÉΓòÉ

 The easiest way to use kerberos is to use the kerberos rsh, as described in
 Connecting via rsh. The main disadvantage of using rsh is that all the data
 needs to pass through additional programs, so it may be slower.  So if you
 have kerberos installed you can connect via a direct TCP connection,
 authenticating with kerberos.

 This section concerns the kerberos network security system, version 4.
 Kerberos version 5 is supported via the GSSAPI generic network security
 interface, as described in the previous section.

 To do this, CVS needs to be compiled with kerberos support; when configuring
 CVS it tries to detect whether kerberos is present or you can use the
 '--with-krb4' flag to configure.

 The data transmitted is not encrypted by default.  Encryption support must be
 compiled into both the client and server; use the '--enable-encryption'
 configure option to turn it on.  You must then use the -x global option to
 request encryption.

 You need to edit inetd.conf on the server machine to run cvs kserver.  The
 client uses port 1999 by default; if you want to use another port specify it
 in the CVS_CLIENT_PORT environment variable on the client.

 When you want to use CVS, get a ticket in the usual way (generally kinit); it
 must be a ticket which allows you to log into the server machine.  Then you
 are ready to go:

                      cvs -d :kserver:chainsaw.yard.com:/usr/local/cvsroot checkout foo

 Previous versions of CVS would fall back to a connection via rsh; this version
 will not do so.


ΓòÉΓòÉΓòÉ 3.10. Read-only repository access ΓòÉΓòÉΓòÉ

     It is possible to grant read-only repository access to people using the
 password-authenticated server (see Password authenticated).  (The other access
 methods do not have explicit support for read-only users because those methods
 all assume login access to the repository machine anyway, and therefore the
 user can do whatever local file permissions allow her to do.)

     A user who has read-only access can do only those CVS operations which do
 not modify the repository, except for certain ``administrative'' files (such
 as lock files and the history file).  It may be desirable to use this feature
 in conjunction with user-aliasing (see Password authentication server).

 Unlike with previous versions of CVS, read-only users should be able merely to
 read the repository, and not to execute programs on the server or otherwise
 gain unexpected levels of access.  Or to be more accurate, the known holes
 have been plugged.  Because this feature is new and has not received a
 comprehensive security audit, you should use whatever level of caution seems
 warranted given your attitude concerning security.

     There are two ways to specify read-only access for a user: by inclusion,
 and by exclusion.

     "Inclusion" means listing that user specifically in the
 '$CVSROOT/CVSROOT/readers' file, which is simply a newline-separated list of
 users.  Here is a sample 'readers' file:

                      melissa
                      splotnik
                      jrandom

     (Don't forget the newline after the last user.)

     "Exclusion" means explicitly listing everyone who has write access---if
 the file

                      $CVSROOT/CVSROOT/writers

 exists, then only those users listed in it have write access, and everyone
 else has read-only access (of course, even the read-only users still need to
 be listed in the CVS 'passwd' file).  The 'writers' file has the same format
 as the 'readers' file.

     Note: if your CVS 'passwd' file maps cvs users onto system users (see
 Password authentication server), make sure you deny or grant read-only access
 using the cvs usernames, not the system usernames.  That is, the 'readers' and
 'writers' files contain cvs usernames, which may or may not be the same as
 system usernames.

     Here is a complete description of the server's behavior in deciding
 whether to grant read-only or read-write access:

     If 'readers' exists, and this user is listed in it, then she gets
 read-only access.  Or if 'writers' exists, and this user is NOT listed in it,
 then she also gets read-only access (this is true even if 'readers' exists but
 she is not listed there).  Otherwise, she gets full read-write access.

     Of course there is a conflict if the user is listed in both files.  This
 is resolved in the more conservative way, it being better to protect the
 repository too much than too little: such a user gets read-only access.


ΓòÉΓòÉΓòÉ 3.11. Temporary directories for the server ΓòÉΓòÉΓòÉ

 While running, the CVS server creates temporary directories.  They are named

                      cvs-servpid

 where pid is the process identification number of the server.  They are
 located in the directory specified by the 'TMPDIR' environment variable (see
 Environment variables), the '-T' global option (see Global options), or
 failing that '/tmp'.

 In most cases the server will remove the temporary directory when it is done,
 whether it finishes normally or abnormally.  However, there are a few cases in
 which the server does not or cannot remove the temporary directory, for
 example:

     If the server aborts due to an internal server error, it may preserve the
      directory to aid in debugging

     If the server is killed in a way that it has no way of cleaning up (most
      notably, 'kill -KILL' on unix).

     If the system shuts down without an orderly shutdown, which tells the
      server to clean up.

 In cases such as this, you will need to manually remove the 'cvs-servpid'
 directories.  As long as there is no server running with process
 identification number pid, it is safe to do so.


ΓòÉΓòÉΓòÉ 4. Starting a project with CVS ΓòÉΓòÉΓòÉ

 Because renaming files and moving them between directories is somewhat
 inconvenient, the first thing you do when you start a new project should be to
 think through your file organization.  It is not impossible to rename or move
 files, but it does increase the potential for confusion and CVS does have some
 quirks particularly in the area of renaming directories.  See Moving files.

 What to do next depends on the situation at hand.

 Setting up the files          Getting the files into the repository
 Defining the module           How to make a module of the files


ΓòÉΓòÉΓòÉ 4.1. Setting up the files ΓòÉΓòÉΓòÉ

 The first step is to create the files inside the repository.  This can be done
 in a couple of different ways.

 From files                    This method is useful with old projects where
                               files already exists.
 From other version control systemsOld projects where you want to preserve
                               history from another system.
 From scratch                  Creating a directory tree from scratch.


ΓòÉΓòÉΓòÉ 4.1.1. Creating a directory tree from a number of files ΓòÉΓòÉΓòÉ

 When you begin using CVS, you will probably already have several projects that
 can be put under CVS control.  In these cases the easiest way is to use the
 import command.  An example is probably the easiest way to explain how to use
 it.  If the files you want to install in CVS reside in 'wdir', and you want
 them to appear in the repository as '$CVSROOT/yoyodyne/rdir', you can do this:

                      $ cd wdir
                      $ cvs import -m "Imported sources" yoyodyne/rdir yoyo start

 Unless you supply a log message with the '-m' flag, CVS starts an editor and
 prompts for a message.  The string 'yoyo' is a vendor tag, and 'start' is a
 release tag.  They may fill no purpose in this context, but since CVS requires
 them they must be present.  See Tracking sources, for more information about
 them.

 You can now verify that it worked, and remove your original source directory.

                      $ cd ┬╖┬╖
                      $ mv dir dir.orig
                      $ cvs checkout yoyodyne/dir    # Explanation below
                      $ diff -r dir.orig yoyodyne/dir
                      $ rm -r dir.orig

 Erasing the original sources is a good idea, to make sure that you do not
 accidentally edit them in dir, bypassing CVS. Of course, it would be wise to
 make sure that you have a backup of the sources before you remove them.

 The checkout command can either take a module name as argument (as it has done
 in all previous examples) or a path name relative to $CVSROOT, as it did in
 the example above.

 It is a good idea to check that the permissions CVS sets on the directories
 inside '$CVSROOT' are reasonable, and that they belong to the proper groups.
 See File permissions.

 If some of the files you want to import are binary, you may want to use the
 wrappers features to specify which files are binary and which are not.  See
 Wrappers.


ΓòÉΓòÉΓòÉ 4.1.2. Creating Files From Other Version Control Systems ΓòÉΓòÉΓòÉ

 If you have a project which you are maintaining with another version control
 system, such as RCS, you may wish to put the files from that project into CVS,
 and preserve the revision history of the files.

 From RCS
           If you have been using RCS, find the RCS files---usually a file
           named 'foo.c' will have its RCS file in 'RCS/foo.c,v' (but it could
           be other places; consult the RCS documentation for details).  Then
           create the appropriate directories in CVS if they do not already
           exist.  Then copy the files into the appropriate directories in the
           CVS repository (the name in the repository must be the name of the
           source file with ',v' added; the files go directly in the appopriate
           directory of the repository, not in an 'RCS' subdirectory).  This is
           one of the few times when it is a good idea to access the CVS
           repository directly, rather than using CVS commands.  Then you are
           ready to check out a new working directory. The RCS file should not
           be locked when you move it into CVS; if it is, CVS will have trouble
           letting you operate on it.

 From another version control system
           Many version control systems have the ability to export RCS files in
           the standard format.  If yours does, export the RCS files and then
           follow the above instructions.

           Failing that, probably your best bet is to write a script that will
           check out the files one revision at a time using the command line
           interface to the other system, and then check the revisions into
           CVS. The 'sccs2rcs' script mentioned below may be a useful example
           to follow.

 From SCCS
           There is a script in the 'contrib' directory of the CVS source
           distribution called 'sccs2rcs' which converts SCCS files to RCS
           files. Note: you must run it on a machine which has both SCCS and
           RCS installed, and like everything else in contrib it is unsupported
           (your mileage may vary).

 From PVCS
           There is a script in the 'contrib' directory of the CVS source
           distribution called 'pvcs_to_rcs' which converts PVCS archives to
           RCS files. You must run it on a machine which has both PVCS and RCS
           installed, and like everything else in contrib it is unsupported
           (your mileage may vary).  See the comments in the script for
           details.


ΓòÉΓòÉΓòÉ 4.1.3. Creating a directory tree from scratch ΓòÉΓòÉΓòÉ

 For a new project, the easiest thing to do is probably to create an empty
 directory structure, like this:

                      $ mkdir tc
                      $ mkdir tc/man
                      $ mkdir tc/testing

 After that, you use the import command to create the corresponding (empty)
 directory structure inside the repository:

                      $ cd tc
                      $ cvs import -m "Created directory structure" yoyodyne/dir yoyo start

 Then, use add to add files (and new directories) as they appear.

 Check that the permissions CVS sets on the directories inside '$CVSROOT' are
 reasonable.


ΓòÉΓòÉΓòÉ 4.2. Defining the module ΓòÉΓòÉΓòÉ

 The next step is to define the module in the 'modules' file.  This is not
 strictly necessary, but modules can be convenient in grouping together related
 files and directories.

 In simple cases these steps are sufficient to define a module.

   1. Get a working copy of the modules file.

                      $ cvs checkout CVSROOT/modules
                      $ cd CVSROOT

   2. Edit the file and insert a line that defines the module.  See Intro
      administrative files, for an introduction.  See modules, for a full
      description of the modules file.  You can use the following line to
      define the module 'tc':

                      tc  yoyodyne/tc

   3. Commit your changes to the modules file.

                      $ cvs commit -m "Added the tc module." modules

   4. Release the modules module.

                      $ cd ┬╖┬╖
                      $ cvs release -d CVSROOT


ΓòÉΓòÉΓòÉ 5. Revisions ΓòÉΓòÉΓòÉ

 For many uses of CVS, one doesn't need to worry too much about revision
 numbers; CVS assigns numbers such as 1.1, 1.2, and so on, and that is all one
 needs to know.  However, some people prefer to have more knowledge and control
 concerning how CVS assigns revision numbers.

 If one wants to keep track of a set of revisions involving more than one file,
 such as which revisions went into a particular release, one uses a tag, which
 is a symbolic revision which can be assigned to a numeric revision in each
 file.

 Revision numbers              The meaning of a revision number
 Versions revisions releases   Terminology used in this manual
 Assigning revisions           Assigning revisions
 Tags                          Tags--Symbolic revisions
 Sticky tags                   Certain tags are persistent


ΓòÉΓòÉΓòÉ 5.1. Revision numbers ΓòÉΓòÉΓòÉ

 Each version of a file has a unique revision number.  Revision numbers look
 like '1.1', '1.2', '1.3.2.2' or even '1.3.2.2.4.5'. A revision number always
 has an even number of period-separated decimal integers.  By default revision
 1.1 is the first revision of a file.  Each successive revision is given a new
 number by increasing the rightmost number by one.  The following figure
 displays a few revisions, with newer revisions to the right.

                          +-----+   +-----+   +-----+   +-----+   +-----+
                          ! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 !
                          +-----+   +-----+   +-----+   +-----+   +-----+

 It is also possible to end up with numbers containing more than one period,
 for example '1.3.2.2'.  Such revisions represent revisions on branches (see
 Branching and merging); such revision numbers are explained in detail in
 Branches and revisions.


ΓòÉΓòÉΓòÉ 5.2. Versions, revisions and releases ΓòÉΓòÉΓòÉ

 A file can have several versions, as described above. Likewise, a software
 product can have several versions. A software product is often given a version
 number such as '4.1.1'.

 Versions in the first sense are called revisions in this document, and
 versions in the second sense are called releases.  To avoid confusion, the
 word version is almost never used in this document.


ΓòÉΓòÉΓòÉ 5.3. Assigning revisions ΓòÉΓòÉΓòÉ

 By default, CVS will assign numeric revisions by leaving the first number the
 same and incrementing the second number.  For example, 1.1, 1.2, 1.3, etc.

 When adding a new file, the second number will always be one and the first
 number will equal the highest first number of any file in that directory.  For
 example, the current directory contains files whose highest numbered revisions
 are 1.7, 3.1, and 4.12, then an added file will be given the numeric revision
 4.1.

 Normally there is no reason to care about the revision numbers---it is easier
 to treat them as internal numbers that CVS maintains, and tags provide a
 better way to distinguish between things like release 1 versus release 2 of
 your product (see Tags).  However, if you want to set the numeric revisions,
 the '-r' option to cvs commit can do that.  The '-r' option implies the '-f'
 option, in the sense that it causes the files to be committed even if they are
 not modified.

 For example, to bring all your files up to revision 3.0 (including those that
 haven't changed), you might invoke:

                      $ cvs commit -r 3.0

 Note that the number you specify with '-r' must be larger than any existing
 revision number.  That is, if revision 3.0 exists, you cannot 'cvs commit -r
 1.3'.  If you want to maintain several releases in parallel, you need to use a
 branch (see Branching and merging).


ΓòÉΓòÉΓòÉ 5.4. Tags--Symbolic revisions ΓòÉΓòÉΓòÉ

 The revision numbers live a life of their own.  They need not have anything at
 all to do with the release numbers of your software product.  Depending on how
 you use CVS the revision numbers might change several times between two
 releases.  As an example, some of the source files that make up RCS 5.6 have
 the following revision numbers:

                      ci.c       5.21
                      co.c       5.9
                      ident.c     5.3
                      rcs.c      5.12
                      rcsbase.h    5.11
                      rcsdiff.c    5.10
                      rcsedit.c    5.11
                      rcsfcmp.c    5.9
                      rcsgen.c     5.10
                      rcslex.c     5.11
                      rcsmap.c     5.2
                      rcsutil.c    5.10

 You can use the tag command to give a symbolic name to a certain revision of a
 file.  You can use the '-v' flag to the status command to see all tags that a
 file has, and which revision numbers they represent.  Tag names must start
 with an uppercase or lowercase letter and can contain uppercase and lowercase
 letters, digits, '-', and '_'.  The two tag names BASE and HEAD are reserved
 for use by CVS.  It is expected that future names which are special to CVS
 will be specially named, for example by starting with '.', rather than being
 named analogously to BASE and HEAD, to avoid conflicts with actual tag names.
 You'll want to choose some convention for naming tags, based on information
 such as the name of the program and the version number of the release.  For
 example, one might take the name of the program, immediately followed by the
 version number with '.' changed to '-', so that CVS 1.9 would be tagged with
 the name cvs1-9.  If you choose a consistent convention, then you won't
 constantly be guessing whether a tag is cvs-1-9 or cvs1_9 or what.  You might
 even want to consider enforcing your convention in the taginfo file (see
 user-defined logging). The following example shows how you can add a tag to a
 file.  The commands must be issued inside your working copy of the module.
 That is, you should issue the command in the directory where 'backend.c'
 resides.

                      $ cvs tag rel-0-4 backend.c
                      T backend.c
                      $ cvs status -v backend.c
                      ===================================================================
                      File: backend.c     Status: Up-to-date
                        Version:       1.4   Tue Dec  1 14:39:01 1992
                        RCS Version:     1.4   /u/cvsroot/yoyodyne/tc/backend.c,v
                        Sticky Tag:     (none)
                        Sticky Date:     (none)
                        Sticky Options:   (none)
                        Existing Tags:
                          rel-0-4           (revision: 1.4)

 There is seldom reason to tag a file in isolation.  A more common use is to
 tag all the files that constitute a module with the same tag at strategic
 points in the development life-cycle, such as when a release is made.

                      $ cvs tag rel-1-0 .
                      cvs tag: Tagging .
                      T Makefile
                      T backend.c
                      T driver.c
                      T frontend.c
                      T parser.c

 (When you give CVS a directory as argument, it generally applies the operation
 to all the files in that directory, and (recursively), to any subdirectories
 that it may contain.  See Recursive behavior.)

 The checkout command has a flag, '-r', that lets you check out a certain
 revision of a module.  This flag makes it easy to retrieve the sources that
 make up release 1.0 of the module 'tc' at any time in the future:

                      $ cvs checkout -r rel-1-0 tc

 This is useful, for instance, if someone claims that there is a bug in that
 release, but you cannot find the bug in the current working copy.

 You can also check out a module as it was at any given date. See checkout
 options.

 When you tag more than one file with the same tag you can think about the tag
 as "a curve drawn through a matrix of filename vs. revision number."  Say we
 have 5 files with the following revisions:

                          file1  file2  file3  file4  file5
                          1.1   1.1   1.1   1.1  /--1.1*    <-*-  TAG
                          1.2*-  1.2   1.2   -1.2*-
                          1.3  \- 1.3*-  1.3  / 1.3
                          1.4      \  1.4  /  1.4
                                 \-1.5*-  1.5
                                  1.6

 At some time in the past, the * versions were tagged. You can think of the tag
 as a handle attached to the curve drawn through the tagged revisions.  When
 you pull on the handle, you get all the tagged revisions.  Another way to look
 at it is that you "sight" through a set of revisions that is "flat" along the
 tagged revisions, like this:

                          file1  file2  file3  file4  file5
                                  1.1
                                  1.2
                              1.1   1.3            _
                          1.1   1.2   1.4   1.1        /
                          1.2*----1.3*----1.5*----1.2*----1.1   (--- <--- Look here
                          1.3       1.6   1.3        \_
                          1.4           1.4
                                      1.5


ΓòÉΓòÉΓòÉ 5.5. Sticky tags ΓòÉΓòÉΓòÉ

 Sometimes a working copy's revision has extra data associated with it, for
 example it might be on a branch (see Branching and merging), or restricted to
 versions prior to a certain date by 'checkout -D' or 'update -D'.  Because
 this data persists -- that is, it applies to subsequent commands in the
 working copy -- we refer to it as sticky.

 Most of the time, stickiness is an obscure aspect of CVS that you don't need
 to think about.  However, even if you don't want to use the feature, you may
 need to know something about sticky tags (for example, how to avoid them!).

 You can use the status command to see if any sticky tags or dates are set:

                      $ cvs status driver.c
                      ===================================================================
                      File: driver.c      Status: Up-to-date
                        Version:       1.7.2.1 Sat Dec  5 19:35:03 1992
                        RCS Version:     1.7.2.1 /u/cvsroot/yoyodyne/tc/driver.c,v
                        Sticky Tag:     rel-1-0-patches (branch: 1.7.2)
                        Sticky Date:     (none)
                        Sticky Options:   (none)

 The sticky tags will remain on your working files until you delete them with
 'cvs update -A'.  The '-A' option retrieves the version of the file from the
 head of the trunk, and forgets any sticky tags, dates, or options.

 The most common use of sticky tags is to identify which branch one is working
 on, as described in Accessing branches.  However, non-branch sticky tags have
 uses as well.  For example, suppose that you want to avoid updating your
 working directory, to isolate yourself from possibly destabilizing changes
 other people are making.  You can, of course, just refrain from running cvs
 update.  But if you want to avoid updating only a portion of a larger tree,
 then sticky tags can help. If you check out a certain revision (such as 1.4)
 it will become sticky.  Subsequent cvs update commands will not retrieve the
 latest revision until you reset the tag with cvs update -A.  Likewise, use of
 the '-D' option to update or checkout sets a sticky date, which, similarly,
 causes that date to be used for future retrievals.

 Many times you will want to retrieve an old version of a file without setting
 a sticky tag.  The way to do that is with the '-p' option to checkout or
 update, which sends the contents of the file to standard output.  For example,
 suppose you have a file named 'file1' which existed as revision 1.1, and you
 then removed it (thus adding a dead revision 1.2). Now suppose you want to add
 it again, with the same contents it had previously.  Here is how to do it:

                      $ cvs update -p -r 1.1 file1 >file1
                      ===================================================================
                      Checking out file1
                      RCS:  /tmp/cvs-sanity/cvsroot/first-dir/Attic/file1,v
                      VERS: 1.1
                      ***************
                      $ cvs add file1
                      cvs add: re-adding file file1 (in place of dead revision 1.2)
                      cvs add: use 'cvs commit' to add this file permanently
                      $ cvs commit -m test
                      Checking in file1;
                      /tmp/cvs-sanity/cvsroot/first-dir/file1,v  <--  file1
                      new revision: 1.3; previous revision: 1.2
                      done
                      $


ΓòÉΓòÉΓòÉ 6. Branching and merging ΓòÉΓòÉΓòÉ

 CVS allows you to isolate changes onto a separate line of development, known
 as a branch.  When you change files on a branch, those changes do not appear
 on the main trunk or other branches.

 Later you can move changes from one branch to another branch (or the main
 trunk) by merging.  Merging involves first running cvs update -j, to merge the
 changes into the working directory. You can then commit that revision, and
 thus effectively copy the changes onto another branch.

 Branches motivation           What branches are good for
 Creating a branch             Creating a branch
 Accessing branches            Checking out and updating branches
 Branches and revisions        Branches are reflected in revision numbers
 Magic branch numbers          Magic branch numbers
 Merging a branch              Merging an entire branch
 Merging more than once        Merging from a branch several times
 Merging two revisions         Merging differences between two revisions
 Merging adds and removals     What if files are added or removed?


ΓòÉΓòÉΓòÉ 6.1. What branches are good for ΓòÉΓòÉΓòÉ

 Suppose that release 1.0 of tc has been made.  You are continuing to develop
 tc, planning to create release 1.1 in a couple of months.  After a while your
 customers start to complain about a fatal bug.  You check out release 1.0 (see
 Tags) and find the bug (which turns out to have a trivial fix).  However, the
 current revision of the sources are in a state of flux and are not expected to
 be stable for at least another month.  There is no way to make a bugfix
 release based on the newest sources.

 The thing to do in a situation like this is to create a branch on the revision
 trees for all the files that make up release 1.0 of tc.  You can then make
 modifications to the branch without disturbing the main trunk.  When the
 modifications are finished you can elect to either incorporate them on the
 main trunk, or leave them on the branch.


ΓòÉΓòÉΓòÉ 6.2. Creating a branch ΓòÉΓòÉΓòÉ

 You can create a branch with tag -b; for example, assuming you're in a working
 copy:

                      $ cvs tag -b rel-1-0-patches

 This splits off a branch based on the current revisions in the working copy,
 assigning that branch the name 'rel-1-0-patches'.

 It is important to understand that branches get created in the repository, not
 in the working copy.  Creating a branch based on current revisions, as the
 above example does, will not automatically switch the working copy to be on
 the new branch.  For information on how to do that, see Accessing branches.

 You can also create a branch without reference to any working copy, by using
 rtag:

                      $ cvs rtag -b -r rel-1-0 rel-1-0-patches tc

 '-r rel-1-0' says that this branch should be rooted at the revision that
 corresponds to the tag 'rel-1-0'.  It need not be the most recent revision --
 it's often useful to split a branch off an old revision (for example, when
 fixing a bug in a past release otherwise known to be stable).

 As with 'tag', the '-b' flag tells rtag to create a branch (rather than just a
 symbolic revision name).  Note that the numeric revision number that matches
 'rel-1-0' will probably be different from file to file.

 So, the full effect of the command is to create a new branch -- named
 'rel-1-0-patches' -- in module 'tc', rooted in the revision tree at the point
 tagged by 'rel-1-0'.


ΓòÉΓòÉΓòÉ 6.3. Accessing branches ΓòÉΓòÉΓòÉ

 You can retrieve a branch in one of two ways: by checking it out fresh from
 the repository, or by switching an existing working copy over to the branch.

 To check out a branch from the repository, invoke 'checkout' with the '-r'
 flag, followed by the tag name of the branch (see Creating a branch):

                      $ cvs checkout -r rel-1-0-patches tc

 Or, if you already have a working copy, you can switch it to a given branch
 with 'update -r':

                      $ cvs update -r rel-1-0-patches tc

 or equivalently:

                      $ cd tc
                      $ cvs update -r rel-1-0-patches

 It does not matter if the working copy was originally on the main trunk or on
 some other branch -- the above command will switch it to the named branch.
 And similarly to a regular 'update' command, 'update -r' merges any changes
 you have made, notifying you of conflicts where they occur.

 Once you have a working copy tied to a particular branch, it remains there
 until you tell it otherwise. This means that changes checked in from the
 working copy will add new revisions on that branch, while leaving the main
 trunk and other branches unaffected.

 To find out what branch a working copy is on, you can use the 'status'
 command.  In its output, look for the field named 'Sticky tag' (see Sticky
 tags) -- that's CVS's way of telling you the branch, if any, of the current
 working files:

                      $ cvs status -v driver.c backend.c
                      ===================================================================
                      File: driver.c      Status: Up-to-date
                        Version:       1.7   Sat Dec  5 18:25:54 1992
                        RCS Version:     1.7   /u/cvsroot/yoyodyne/tc/driver.c,v
                        Sticky Tag:     rel-1-0-patches (branch: 1.7.2)
                        Sticky Date:     (none)
                        Sticky Options:   (none)
                        Existing Tags:
                          rel-1-0-patches       (branch: 1.7.2)
                          rel-1-0           (revision: 1.7)
                      ===================================================================
                      File: backend.c     Status: Up-to-date
                        Version:       1.4   Tue Dec  1 14:39:01 1992
                        RCS Version:     1.4   /u/cvsroot/yoyodyne/tc/backend.c,v
                        Sticky Tag:     rel-1-0-patches (branch: 1.4.2)
                        Sticky Date:     (none)
                        Sticky Options:   (none)
                        Existing Tags:
                          rel-1-0-patches       (branch: 1.4.2)
                          rel-1-0           (revision: 1.4)
                          rel-0-4           (revision: 1.4)

 Don't be confused by the fact that the branch numbers for each file are
 different ('1.7.2' and '1.4.2' respectively).  The branch tag is the same,
 'rel-1-0-patches', and the files are indeed on the same branch.  The numbers
 simply reflect the point in each file's revision history at which the branch
 was made.  In the above example, one can deduce that 'driver.c' had been
 through more changes than 'backend.c' before this branch was created.

 See Branches and revisions for details about how branch numbers are
 constructed.


ΓòÉΓòÉΓòÉ 6.4. Branches and revisions ΓòÉΓòÉΓòÉ

 Ordinarily, a file's revision history is a linear series of increments (see
 Revision numbers):

                          +-----+   +-----+   +-----+   +-----+   +-----+
                          ! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 !
                          +-----+   +-----+   +-----+   +-----+   +-----+

 However, CVS is not limited to linear development.  The revision tree can be
 split into branches, where each branch is a self-maintained line of
 development.  Changes made on one branch can easily be moved back to the main
 trunk.

 Each branch has a branch number, consisting of an odd number of
 period-separated decimal integers.  The branch number is created by appending
 an integer to the revision number where the corresponding branch forked off.
 Having branch numbers allows more than one branch to be forked off from a
 certain revision.

 All revisions on a branch have revision numbers formed by appending an ordinal
 number to the branch number. The following figure illustrates branching with
 an example.

                                         +-------------+
                            Branch 1.2.2.3.2 ->     ! 1.2.2.3.2.1 !
                                        / +-------------+
                                        /
                                       /
                               +---------+   +---------+   +---------+
                      Branch 1.2.2 -> _! 1.2.2.1 !----! 1.2.2.2 !----! 1.2.2.3 !
                              / +---------+   +---------+   +---------+
                             /
                             /
                      +-----+   +-----+   +-----+   +-----+   +-----+
                      ! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 !  <- The main trunk
                      +-----+   +-----+   +-----+   +-----+   +-----+
                              !
                              !
                              !  +---------+   +---------+   +---------+
                      Branch 1.2.4 -> +---! 1.2.4.1 !----! 1.2.4.2 !----! 1.2.4.3 !
                                +---------+   +---------+   +---------+

 The exact details of how the branch number is constructed is not something you
 normally need to be concerned about, but here is how it works: When CVS
 creates a branch number it picks the first unused even integer, starting with
 2.  So when you want to create a branch from revision 6.4 it will be numbered
 6.4.2.  All branch numbers ending in a zero (such as 6.4.0) are used
 internally by CVS (see Magic branch numbers).  The branch 1.1.1 has a special
 meaning.  See Tracking sources.


ΓòÉΓòÉΓòÉ 6.5. Magic branch numbers ΓòÉΓòÉΓòÉ

 This section describes a CVS feature called magic branches.  For most
 purposes, you need not worry about magic branches; CVS handles them for you.
 However, they are visible to you in certain circumstances, so it may be useful
 to have some idea of how it works.

 Externally, branch numbers consist of an odd number of dot-separated decimal
 integers.  See Revision numbers.  That is not the whole truth, however.  For
 efficiency reasons CVS sometimes inserts an extra 0 in the second rightmost
 position (1.2.4 becomes 1.2.0.4, 8.9.10.11.12 becomes 8.9.10.11.0.12 and so
 on).

 CVS does a pretty good job at hiding these so called magic branches, but in a
 few places the hiding is incomplete:

     The magic branch number appears in the output from cvs log.

     You cannot specify a symbolic branch name to cvs admin.

 You can use the admin command to reassign a symbolic name to a branch the way
 RCS expects it to be.  If R4patches is assigned to the branch 1.4.2 (magic
 branch number 1.4.0.2) in file 'numbers.c' you can do this:

                      $ cvs admin -NR4patches:1.4.2 numbers.c

 It only works if at least one revision is already committed on the branch.  Be
 very careful so that you do not assign the tag to the wrong number.  (There is
 no way to see how the tag was assigned yesterday).


ΓòÉΓòÉΓòÉ 6.6. Merging an entire branch ΓòÉΓòÉΓòÉ

 You can merge changes made on a branch into your working copy by giving the
 '-j branch' flag to the update command.  With one '-j branch' option it merges
 the changes made between the point where the branch forked and newest revision
 on that branch (into your working copy).

 The '-j' stands for ``join''.

 Consider this revision tree:

                      +-----+   +-----+   +-----+   +-----+
                      ! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !    <- The main trunk
                      +-----+   +-----+   +-----+   +-----+
                              !
                              !
                              !  +---------+   +---------+
                      Branch R1fix -> +---! 1.2.2.1 !----! 1.2.2.2 !
                                +---------+   +---------+

 The branch 1.2.2 has been given the tag (symbolic name) 'R1fix'.  The
 following example assumes that the module 'mod' contains only one file, 'm.c'.

                      $ cvs checkout mod        # Retrieve the latest revision, 1.4
                      $ cvs update -j R1fix m.c     # Merge all changes made on the branch,
                                       # i.e. the changes between revision 1.2
                                       # and 1.2.2.2, into your working copy
                                       # of the file.
                      $ cvs commit -m "Included R1fix" # Create revision 1.5.

 A conflict can result from a merge operation.  If that happens, you should
 resolve it before committing the new revision.  See Conflicts example.

 The checkout command also supports the '-j branch' flag.  The same effect as
 above could be achieved with this:

                      $ cvs checkout -j R1fix mod
                      $ cvs commit -m "Included R1fix"


ΓòÉΓòÉΓòÉ 6.7. Merging from a branch several times ΓòÉΓòÉΓòÉ

 Continuing our example, the revision tree now looks like this:

                      +-----+   +-----+   +-----+   +-----+   +-----+
                      ! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 !  <- The main trunk
                      +-----+   +-----+   +-----+   +-----+   +-----+
                              !              *
                              !              *
                              !  +---------+   +---------+
                      Branch R1fix -> +---! 1.2.2.1 !----! 1.2.2.2 !
                                +---------+   +---------+

 where the starred line represents the merge from the 'R1fix' branch to the
 main trunk, as just discussed.

 Now suppose that development continues on the 'R1fix' branch:

                      +-----+   +-----+   +-----+   +-----+   +-----+
                      ! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 !  <- The main trunk
                      +-----+   +-----+   +-----+   +-----+   +-----+
                              !              *
                              !              *
                              !  +---------+   +---------+   +---------+
                      Branch R1fix -> +---! 1.2.2.1 !----! 1.2.2.2 !----! 1.2.2.3 !
                                +---------+   +---------+   +---------+

 and then you want to merge those new changes onto the main trunk.  If you just
 use the cvs update -j R1fix m.c command again, CVS will attempt to merge again
 the changes which you have already merged, which can have undesirable side
 effects.

 So instead you need to specify that you only want to merge the changes on the
 branch which have not yet been merged into the trunk.  To do that you specify
 two '-j' options, and CVS merges the changes from the first revision to the
 second revision.  For example, in this case the simplest way would be

                      cvs update -j 1.2.2.2 -j R1fix m.c   # Merge changes from 1.2.2.2 to the
                                         # head of the R1fix branch

 The problem with this is that you need to specify the 1.2.2.2 revision
 manually.  A slightly better approach might be to use the date the last merge
 was done:

                      cvs update -j R1fix:yesterday -j R1fix m.c

 Better yet, tag the R1fix branch after every merge into the trunk, and then
 use that tag for subsequent merges:

                      cvs update -j merged_from_R1fix_to_trunk -j R1fix m.c


ΓòÉΓòÉΓòÉ 6.8. Merging differences between any two revisions ΓòÉΓòÉΓòÉ

 With two '-j revision' flags, the update (and checkout) command can merge the
 differences between any two revisions into your working file.

                      $ cvs update -j 1.5 -j 1.3 backend.c

 will remove all changes made between revision 1.3 and 1.5.  Note the order of
 the revisions!

 If you try to use this option when operating on multiple files, remember that
 the numeric revisions will probably be very different between the various
 files that make up a module.  You almost always use symbolic tags rather than
 revision numbers when operating on multiple files.


ΓòÉΓòÉΓòÉ 6.9. Merging can add or remove files ΓòÉΓòÉΓòÉ

 If the changes which you are merging involve removing or adding some files,
 update -j will reflect such additions or removals.

 For example:

                      cvs update -A
                      touch a b c
                      cvs add a b c ; cvs ci -m "added" a b c
                      cvs tag -b branchtag
                      cvs update -r branchtag
                      touch d ; cvs add d
                      rm a ; cvs rm a
                      cvs ci -m "added d, removed a"
                      cvs update -A
                      cvs update -jbranchtag

 After these commands are executed and a 'cvs commit' is done, file 'a' will be
 removed and file 'd' added in the main branch.


ΓòÉΓòÉΓòÉ 7. Recursive behavior ΓòÉΓòÉΓòÉ

 Almost all of the subcommands of CVS work recursively when you specify a
 directory as an argument.  For instance, consider this directory structure:

                         $HOME
                          |
                          +--tc
                          |  |
                            +--CVS
                            |    (internal CVS files)
                            +--Makefile
                            +--backend.c
                            +--driver.c
                            +--frontend.c
                            +--parser.c
                            +--man
                            |   |
                            |   +--CVS
                            |   |  (internal CVS files)
                            |   +--tc.1
                            |
                            +--testing
                               |
                               +--CVS
                               |  (internal CVS files)
                               +--testpgm.t
                               +--test2.t

 If 'tc' is the current working directory, the following is true:

     'cvs update testing' is equivalent to

                      cvs update testing/testpgm.t testing/test2.t

     'cvs update testing man' updates all files in the subdirectories

     'cvs update .' or just 'cvs update' updates all files in the tc module

 If no arguments are given to update it will update all files in the current
 working directory and all its subdirectories.  In other words, '.' is a
 default argument to update.  This is also true for most of the CVS
 subcommands, not only the update command.

 The recursive behavior of the CVS subcommands can be turned off with the '-l'
 option. Conversely, the '-R' option can be used to force recursion if '-l' is
 specified in '~/.cvsrc' (see ~/.cvsrc).

                      $ cvs update -l     # Don't update files in subdirectories


ΓòÉΓòÉΓòÉ 8. Adding, removing, and renaming files and directories ΓòÉΓòÉΓòÉ

 In the course of a project, one will often add new files.  Likewise with
 removing or renaming, or with directories.  The general concept to keep in
 mind in all these cases is that instead of making an irreversible change you
 want CVS to record the fact that a change has taken place, just as with
 modifying an existing file.  The exact mechanisms to do this in CVS vary
 depending on the situation.

 Adding files                  Adding files
 Removing files                Removing files
 Removing directories          Removing directories
 Moving files                  Moving and renaming files
 Moving directories            Moving and renaming directories


ΓòÉΓòÉΓòÉ 8.1. Adding files to a directory ΓòÉΓòÉΓòÉ

 To add a new file to a directory, follow these steps.

     You must have a working copy of the directory. See Getting the source.

     Create the new file inside your working copy of the directory.

     Use 'cvs add filename' to tell CVS that you want to version control the
      file.  If the file contains binary data, specify '-kb' (see Binary
      files).

     Use 'cvs commit filename' to actually check in the file into the
      repository.  Other developers cannot see the file until you perform this
      step.

 You can also use the add command to add a new directory. Unlike most other
 commands, the add command is not recursive.  You cannot even type 'cvs add
 foo/bar'!  Instead, you have to

                      $ cd foo
                      $ cvs add bar

 cvs add  [-k kflag] [-m message] files ┬╖┬╖┬╖   (Command)

           Schedule files to be added to the repository. The files or
           directories specified with add must already exist in the current
           directory.  To add a whole new directory hierarchy to the source
           repository (for example, files received from a third-party vendor),
           use the import command instead.  See import.

           The added files are not placed in the source repository until you
           use commit to make the change permanent.  Doing an add on a file
           that was removed with the remove command will undo the effect of the
           remove, unless a commit command intervened.  See Removing files, for
           an example.

           The '-k' option specifies the default way that this file will be
           checked out; for more information see Substitution modes.

           The '-m' option specifies a description for the file.  This
           description appears in the history log (if it is enabled, see
           history file).  It will also be saved in the version history inside
           the repository when the file is committed.  The log command displays
           this description.  The description can be changed using 'admin -t'.
           See admin.  If you omit the '-m description' flag, an empty string
           will be used.  You will not be prompted for a description.

 For example, the following commands add the file 'backend.c' to the
 repository:

                      $ cvs add backend.c
                      $ cvs commit -m "Early version. Not yet compilable." backend.c

 When you add a file it is added only on the branch which you are working on
 (see Branching and merging).  You can later merge the additions to another
 branch if you want (see Merging adds and removals).


ΓòÉΓòÉΓòÉ 8.2. Removing files ΓòÉΓòÉΓòÉ

 Modules change.  New files are added, and old files disappear.  Still, you
 want to be able to retrieve an exact copy of old releases.

 Here is what you can do to remove a file, but remain able to retrieve old
 revisions:

     Make sure that you have not made any uncommitted modifications to the
      file.  See Viewing differences, for one way to do that.  You can also use
      the status or update command.  If you remove the file without committing
      your changes, you will of course not be able to retrieve the file as it
      was immediately before you deleted it.

     Remove the file from your working copy of the directory. You can for
      instance use rm.

     Use 'cvs remove filename' to tell CVS that you really want to delete the
      file.

     Use 'cvs commit filename' to actually perform the removal of the file
      from the repository.

 When you commit the removal of the file, CVS records the fact that the file no
 longer exists.  It is possible for a file to exist on only some branches and
 not on others, or to re-add another file with the same name later.  CVS will
 correctly create or not create the file, based on the '-r' and '-D' options
 specified to checkout or update.

 cvs remove  [options] files ┬╖┬╖┬╖   (Command)

           Schedule file(s) to be removed from the repository (files which have
           not already been removed from the working directory are not
           processed).  This command does not actually remove the file from the
           repository until you commit the removal.  For a full list of
           options, see Invoking CVS.

 Here is an example of removing several files:

                      $ cd test
                      $ rm *.c
                      $ cvs remove
                      cvs remove: Removing .
                      cvs remove: scheduling a.c for removal
                      cvs remove: scheduling b.c for removal
                      cvs remove: use 'cvs commit' to remove these files permanently
                      $ cvs ci -m "Removed unneeded files"
                      cvs commit: Examining .
                      cvs commit: Committing .

 As a convenience you can remove the file and cvs remove it in one step, by
 specifying the '-f' option.  For example, the above example could also be done
 like this:

                      $ cd test
                      $ cvs remove -f *.c
                      cvs remove: scheduling a.c for removal
                      cvs remove: scheduling b.c for removal
                      cvs remove: use 'cvs commit' to remove these files permanently
                      $ cvs ci -m "Removed unneeded files"
                      cvs commit: Examining .
                      cvs commit: Committing .

 If you execute remove for a file, and then change your mind before you commit,
 you can undo the remove with an add command.

                      $ ls
                      CVS  ja.h  oj.c
                      $ rm oj.c
                      $ cvs remove oj.c
                      cvs remove: scheduling oj.c for removal
                      cvs remove: use 'cvs commit' to remove this file permanently
                      $ cvs add oj.c
                      U oj.c
                      cvs add: oj.c, version 1.1.1.1, resurrected

 If you realize your mistake before you run the remove command you can use
 update to resurrect the file:

                      $ rm oj.c
                      $ cvs update oj.c
                      cvs update: warning: oj.c was lost
                      U oj.c

 When you remove a file it is removed only on the branch which you are working
 on (see Branching and merging).  You can later merge the removals to another
 branch if you want (see Merging adds and removals).


ΓòÉΓòÉΓòÉ 8.3. Removing directories ΓòÉΓòÉΓòÉ

 In concept removing directories is somewhat similar to removing files---you
 want the directory to not exist in your current working directories, but you
 also want to be able to retrieve old releases in which the directory existed.

 The way that you remove a directory is to remove all the files in it.  You
 don't remove the directory itself; there is no way to do that. Instead you
 specify the '-P' option to cvs update, cvs checkout, or cvs export, which will
 cause CVS to remove empty directories from working directories.  Probably the
 best way to do this is to always specify '-P'; if you want an empty directory
 then put a dummy file (for example '.keepme') in it to prevent '-P' from
 removing it.

 Note that '-P' is implied by the '-r' or '-D' options of checkout and export.
 This way CVS will be able to correctly create the directory or not depending
 on whether the particular version you are checking out contains any files in
 that directory.


ΓòÉΓòÉΓòÉ 8.4. Moving and renaming files ΓòÉΓòÉΓòÉ

 Moving files to a different directory or renaming them is not difficult, but
 some of the ways in which this works may be non-obvious.  (Moving or renaming
 a directory is even harder.  See Moving directories.).

 The examples below assume that the file old is renamed to new.

 Outside                       The normal way to Rename
 Inside                        A tricky, alternative way
 Rename by copying             Another tricky, alternative way


ΓòÉΓòÉΓòÉ 8.4.1. The Normal way to Rename ΓòÉΓòÉΓòÉ

 The normal way to move a file is to copy old to new, and then issue the normal
 CVS commands to remove old from the repository, and add new to it.

                      $ mv old new
                      $ cvs remove old
                      $ cvs add new
                      $ cvs commit -m "Renamed old to new" old new

 This is the simplest way to move a file, it is not error-prone, and it
 preserves the history of what was done.  Note that to access the history of
 the file you must specify the old or the new name, depending on what portion
 of the history you are accessing.  For example, cvs log old will give the log
 up until the time of the rename.

 When new is committed its revision numbers will start again, usually at 1.1,
 so if that bothers you, use the '-r rev' option to commit.  For more
 information see Assigning revisions.


ΓòÉΓòÉΓòÉ 8.4.2. Moving the history file ΓòÉΓòÉΓòÉ

 This method is more dangerous, since it involves moving files inside the
 repository.  Read this entire section before trying it out!

                      $ cd $CVSROOT/module
                      $ mv old,v new,v

 Advantages:

     The log of changes is maintained intact.

     The revision numbers are not affected.

 Disadvantages:

     Old releases of the module cannot easily be fetched from the repository.
      (The file will show up as new even in revisions from the time before it
      was renamed).

     There is no log information of when the file was renamed.

     Nasty things might happen if someone accesses the history file while you
      are moving it.  Make sure no one else runs any of the CVS commands while
      you move it.


ΓòÉΓòÉΓòÉ 8.4.3. Copying the history file ΓòÉΓòÉΓòÉ

 This way also involves direct modifications to the repository.  It is safe,
 but not without drawbacks.

                      # Copy the RCS file inside the repository
                      $ cd $CVSROOT/module
                      $ cp old,v new,v
                      # Remove the old file
                      $ cd ~/module
                      $ rm old
                      $ cvs remove old
                      $ cvs commit old
                      # Remove all tags from new
                      $ cvs update new
                      $ cvs log new       # Remember the non-branch tag names
                      $ cvs tag -d tag1 new
                      $ cvs tag -d tag2 new
                      ┬╖┬╖┬╖

 By removing the tags you will be able to check out old revisions of the
 module.
 Advantages:

     Checking out old revisions works correctly, as long as you use '-rtag'
      and not '-Ddate' to retrieve the revisions.

     The log of changes is maintained intact.

     The revision numbers are not affected.

 Disadvantages:

     You cannot easily see the history of the file across the rename.


ΓòÉΓòÉΓòÉ 8.5. Moving and renaming directories ΓòÉΓòÉΓòÉ

 The normal way to rename or move a directory is to rename or move each file
 within it as described in Outside.  Then check out with the '-P' option, as
 described in Removing directories.

 If you really want to hack the repository to rename or delete a directory in
 the repository, you can do it like this:

   1. Inform everyone who has a copy of the module that the directory will be
      renamed.  They should commit all their changes, and remove their working
      copies of the module, before you take the steps below.

   2. Rename the directory inside the repository.

                      $ cd $CVSROOT/module
                      $ mv old-dir new-dir

   3. Fix the CVS administrative files, if necessary (for instance if you
      renamed an entire module).

   4. Tell everyone that they can check out the module and continue working.

 If someone had a working copy of the module the CVS commands will cease to
 work for him, until he removes the directory that disappeared inside the
 repository.

 It is almost always better to move the files in the directory instead of
 moving the directory.  If you move the directory you are unlikely to be able
 to retrieve old releases correctly, since they probably depend on the name of
 the directories.


ΓòÉΓòÉΓòÉ 9. History browsing ΓòÉΓòÉΓòÉ

 Once you have used CVS to store a version control history---what files have
 changed when, how, and by whom, there are a variety of mechanisms for looking
 through the history.

 log messages                  Log messages
 history database              The history database
 user-defined logging          User-defined logging
 annotate                      What revision modified each line of a file?


ΓòÉΓòÉΓòÉ 9.1. Log messages ΓòÉΓòÉΓòÉ

 Whenever you commit a file you specify a log message.

 To look through the log messages which have been specified for every revision
 which has been committed, use the cvs log command (see log).


ΓòÉΓòÉΓòÉ 9.2. The history database ΓòÉΓòÉΓòÉ

 You can use the history file (see history file) to log various CVS actions.
 To retrieve the information from the history file, use the cvs history command
 (see history).


ΓòÉΓòÉΓòÉ 9.3. User-defined logging ΓòÉΓòÉΓòÉ

 You can customize CVS to log various kinds of actions, in whatever manner you
 choose.  These mechanisms operate by executing a script at various times.  The
 script might append a message to a file listing the information and the
 programmer who created it, or send mail to a group of developers, or, perhaps,
 post a message to a particular newsgroup.  To log commits, use the 'loginfo'
 file (see loginfo). To log commits, checkouts, exports, and tags,
 respectively, you can also use the '-i', '-o', '-e', and '-t' options in the
 modules file.  For a more flexible way of giving notifications to various
 users, which requires less in the way of keeping centralized scripts up to
 date, use the cvs watch add command (see Getting Notified); this command is
 useful even if you are not using cvs watch on.

 The 'taginfo' file defines programs to execute when someone executes a tag or
 rtag command.  The 'taginfo' file has the standard form for administrative
 files (see Administrative files), where each line is a regular expression
 followed by a command to execute.  The arguments passed to the command are, in
 order, the tagname, operation (add for tag, mov for tag -F, and del for tag
 -d), repository, and any remaining are pairs of filename revision.  A non-zero
 exit of the filter program will cause the tag to be aborted.

 Here is an example of using taginfo to log tag and rtag commands.  In the
 taginfo file put:

                      ALL /usr/local/cvsroot/CVSROOT/loggit

 Where '/usr/local/cvsroot/CVSROOT/loggit' contains the following script:

                      #!/bin/sh
                      echo "$@" >>/home/kingdon/cvsroot/CVSROOT/taglog


ΓòÉΓòÉΓòÉ 9.4. Annotate command ΓòÉΓòÉΓòÉ

 cvs annotate  [-flR] [-r rev|-D date] files ┬╖┬╖┬╖   (Command)

           For each file in files, print the head revision of the trunk,
           together with information on the last modification for each line.
           For example:

                                          $ cvs annotate ssfile
                                          Annotations for ssfile
                                          ***************
                                          1.1      (mary   27-Mar-96): ssfile line 1
                                          1.2      (joe    28-Mar-96): ssfile line 2

           The file 'ssfile' currently contains two lines. The ssfile line 1
           line was checked in by mary on March 27.  Then, on March 28, joe
           added a line ssfile line 2, without modifying the ssfile line 1
           line.  This report doesn't tell you anything about lines which have
           been deleted or replaced; you need to use cvs diff for that (see
           diff).

 The options to cvs annotate are listed in Invoking CVS, and can be used to
 select the files and revisions to annotate.  The options are described in more
 detail in Common options.


ΓòÉΓòÉΓòÉ 10. Handling binary files ΓòÉΓòÉΓòÉ

 The most common use for CVS is to store text files.  With text files, CVS can
 merge revisions, display the differences between revisions in a human-visible
 fashion, and other such operations. However, if you are willing to give up a
 few of these abilities, CVS can store binary files.  For example, one might
 store a web site in CVS including both text files and binary images.

 Binary why                    More details on issues with binary files
 Binary howto                  How to store them


ΓòÉΓòÉΓòÉ 10.1. The issues with binary files ΓòÉΓòÉΓòÉ

 While the need to manage binary files may seem obvious if the files that you
 customarily work with are binary, putting them into version control does
 present some additional issues.

 One basic function of version control is to show the differences between two
 revisions.  For example, if someone else checked in a new version of a file,
 you may wish to look at what they changed and determine whether their changes
 are good.  For text files, CVS provides this functionality via the cvs diff
 command.  For binary files, it may be possible to extract the two revisions
 and then compare them with a tool external to CVS (for example, word
 processing software often has such a feature).  If there is no such tool, one
 must track changes via other mechanisms, such as urging people to write good
 log messages, and hoping that the changes they actually made were the changes
 that they intended to make.

 Another ability of a version control system is the ability to merge two
 revisions.  For CVS this happens in two contexts.  The first is when users
 make changes in separate working directories (see Multiple developers).  The
 second is when one merges explicitly with the 'update -j' command (see
 Branching and merging).

 In the case of text files, CVS can merge changes made independently, and
 signal a conflict if the changes conflict.  With binary files, the best that
 CVS can do is present the two different copies of the file, and leave it to
 the user to resolve the conflict.  The user may choose one copy or the other,
 or may run an external merge tool which knows about that particular file
 format, if one exists. Note that having the user merge relies primarily on the
 user to not accidentally omit some changes, and thus is potentially error
 prone.

 If this process is thought to be undesirable, the best choice may be to avoid
 merging.  To avoid the merges that result from separate working directories,
 see the discussion of reserved checkouts (file locking) in Multiple
 developers.  To avoid the merges resulting from branches, restrict use of
 branches.


ΓòÉΓòÉΓòÉ 10.2. How to store binary files ΓòÉΓòÉΓòÉ

 There are two issues with using CVS to store binary files.  The first is that
 CVS by default converts line endings between the canonical form in which they
 are stored in the repository (linefeed only), and the form appropriate to the
 operating system in use on the client (for example, carriage return followed
 by line feed for Windows NT).

 The second is that a binary file might happen to contain data which looks like
 a keyword (see Keyword substitution), so keyword expansion must be turned off.

 The '-kb' option available with some CVS commands insures that neither line
 ending conversion nor keyword expansion will be done.

 Here is an example of how you can create a new file using the '-kb' flag:

                      $ echo '${}Id$' > kotest
                      $ cvs add -kb -m"A test file" kotest
                      $ cvs ci -m"First checkin; contains a keyword" kotest

 If a file accidentally gets added without '-kb', one can use the cvs admin
 command to recover. For example:

                      $ echo '${}Id$' > kotest
                      $ cvs add -m"A test file" kotest
                      $ cvs ci -m"First checkin; contains a keyword" kotest
                      $ cvs admin -kb kotest
                      $ cvs update -A kotest
                      # For non-unix systems:
                      # Copy in a good copy of the file from outside CVS
                      $ cvs commit -m "make it binary" kotest

 When you check in the file 'kotest' the file is not preserved as a binary
 file, because you did not check it in as a binary file.  The cvs admin -kb
 command sets the default keyword substitution method for this file, but it
 does not alter the working copy of the file that you have.  If you need to
 cope with line endings (that is, you are using CVS on a non-unix system), then
 you need to check in a new copy of the file, as shown by the cvs commit
 command above. On unix, the cvs update -A command suffices. However, in using
 cvs admin -k to change the keyword expansion, be aware that the keyword
 expansion mode is not version controlled.  This means that, for example, that
 if you have a text file in old releases, and a binary file with the same name
 in new releases, CVS provides no way to check out the file in text or binary
 mode depending on what version you are checking out.  There is no good
 workaround for this problem.

 You can also set a default for whether cvs add and cvs import treat a file as
 binary based on its name; for example you could say that files who names end
 in '.exe' are binary.  See Wrappers. There is currently no way to have CVS
 detect whether a file is binary based on its contents.  The main difficulty
 with designing such a feature is that it is not clear how to distinguish
 between binary and non-binary files, and the rules to apply would vary
 considerably with the operating system.


ΓòÉΓòÉΓòÉ 11. Multiple developers ΓòÉΓòÉΓòÉ

 When more than one person works on a software project things often get
 complicated.  Often, two people try to edit the same file simultaneously.  One
 solution, known as file locking or reserved checkouts, is to allow only one
 person to edit each file at a time. This is the only solution with some
 version control systems, including RCS and SCCS.  Currently the usual way to
 get reserved checkouts with CVS is the cvs admin -l command (see admin
 options).  This is not as nicely integrated into CVS as the watch features,
 described below, but it seems that most people with a need for reserved
 checkouts find it adequate. It also may be possible to use the watches
 features described below, together with suitable procedures (not enforced by
 software), to avoid having two people edit at the same time.

 The default model with CVS is known as unreserved checkouts.  In this model,
 developers can edit their own working copy of a file simultaneously.  The
 first person that commits his changes has no automatic way of knowing that
 another has started to edit it.  Others will get an error message when they
 try to commit the file.  They must then use CVS commands to bring their
 working copy up to date with the repository revision.  This process is almost
 automatic.

 CVS also supports mechanisms which facilitate various kinds of communcation,
 without actually enforcing rules like reserved checkouts do.

 The rest of this chapter describes how these various models work, and some of
 the issues involved in choosing between them.

 File status                   A file can be in several states
 Updating a file               Bringing a file up-to-date
 Conflicts example             An informative example
 Informing others              To cooperate you must inform
 Concurrency                   Simultaneous repository access
 Watches                       Mechanisms to track who is editing files
 Choosing a model              Reserved or unreserved checkouts?


ΓòÉΓòÉΓòÉ 11.1. File status ΓòÉΓòÉΓòÉ

 Based on what operations you have performed on a checked out file, and what
 operations others have performed to that file in the repository, one can
 classify a file in a number of states.  The states, as reported by the status
 command, are:

 Up-to-date
           The file is identical with the latest revision in the repository for
           the branch in use.

 Locally Modified
           You have edited the file, and not yet committed your changes.

 Locally Added
           You have added the file with add, and not yet committed your
           changes.

 Locally Removed
           You have removed the file with remove, and not yet committed your
           changes.

 Needs Checkout
           Someone else has committed a newer revision to the repository.  The
           name is slightly misleading; you will ordinarily use update rather
           than checkout to get that newer revision.

 Needs Patch
           Like Needs Checkout, but the CVS server will send a patch rather
           than the entire file.  Sending a patch or sending an entire file
           accomplishes the same thing.

 Needs Merge
           Someone else has committed a newer revision to the repository, and
           you have also made modifications to the file.

 File had conflicts on merge
           This is like Locally Modified, except that a previous update command
           gave a conflict.  If you have not already done so, you need to
           resolve the conflict as described in Conflicts example.

 Unknown
           CVS doesn't know anything about this file.  For example, you have
           created a new file and have not run add.

 To help clarify the file status, status also reports the Working revision
 which is the revision that the file in the working directory derives from, and
 the Repository revision which is the latest revision in the repository for the
 branch in use. The options to status are listed in Invoking CVS.  For
 information on its Sticky tag and Sticky date output, see Sticky tags. For
 information on its Sticky options output, see the '-k' option in update
 options.

 You can think of the status and update commands as somewhat complementary.
 You use update to bring your files up to date, and you can use status to give
 you some idea of what an update would do (of course, the state of the
 repository might change before you actually run update).  In fact, if you want
 a command to display file status in a more brief format than is displayed by
 the status command, you can invoke

                      $ cvs -n -q update

 The '-n' option means to not actually do the update, but merely to display
 statuses; the '-q' option avoids printing the name of each directory.  For
 more information on the update command, and these options, see Invoking CVS.


ΓòÉΓòÉΓòÉ 11.2. Bringing a file up to date ΓòÉΓòÉΓòÉ

 When you want to update or merge a file, use the update command.  For files
 that are not up to date this is roughly equivalent to a checkout command: the
 newest revision of the file is extracted from the repository and put in your
 working copy of the module.

 Your modifications to a file are never lost when you use update.  If no newer
 revision exists, running update has no effect.  If you have edited the file,
 and a newer revision is available, CVS will merge all changes into your
 working copy.

 For instance, imagine that you checked out revision 1.4 and started editing
 it.  In the meantime someone else committed revision 1.5, and shortly after
 that revision 1.6.  If you run update on the file now, CVS will incorporate
 all changes between revision 1.4 and 1.6 into your file.

 If any of the changes between 1.4 and 1.6 were made too close to any of the
 changes you have made, an overlap occurs.  In such cases a warning is printed,
 and the resulting file includes both versions of the lines that overlap,
 delimited by special markers. See update, for a complete description of the
 update command.


ΓòÉΓòÉΓòÉ 11.3. Conflicts example ΓòÉΓòÉΓòÉ

 Suppose revision 1.4 of 'driver.c' contains this:

                      #include <stdio.h>
                      void main()
                      {
                        parse();
                        if (nerr == 0)
                          gencode();
                        else
                          fprintf(stderr, "No code generated.\n");
                        exit(nerr == 0 ? 0 : 1);
                      }

 Revision 1.6 of 'driver.c' contains this:

                      #include <stdio.h>
                      int main(int argc,
                           char **argv)
                      {
                        parse();
                        if (argc != 1)
                        {
                          fprintf(stderr, "tc: No args expected.\n");
                          exit(1);
                        }
                        if (nerr == 0)
                          gencode();
                        else
                          fprintf(stderr, "No code generated.\n");
                        exit(!!nerr);
                      }

 Your working copy of 'driver.c', based on revision 1.4, contains this before
 you run 'cvs update':

                      #include <stdlib.h>
                      #include <stdio.h>
                      void main()
                      {
                        init_scanner();
                        parse();
                        if (nerr == 0)
                          gencode();
                        else
                          fprintf(stderr, "No code generated.\n");
                        exit(nerr == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
                      }

 You run 'cvs update':

                      $ cvs update driver.c
                      RCS file: /usr/local/cvsroot/yoyodyne/tc/driver.c,v
                      retrieving revision 1.4
                      retrieving revision 1.6
                      Merging differences between 1.4 and 1.6 into driver.c
                      rcsmerge warning: overlaps during merge
                      cvs update: conflicts found in driver.c
                      C driver.c

 CVS tells you that there were some conflicts. Your original working file is
 saved unmodified in '.#driver.c.1.4'.  The new version of 'driver.c' contains
 this:

                      #include <stdlib.h>
                      #include <stdio.h>
                      int main(int argc,
                           char **argv)
                      {
                        init_scanner();
                        parse();
                        if (argc != 1)
                        {
                          fprintf(stderr, "tc: No args expected.\n");
                          exit(1);
                        }
                        if (nerr == 0)
                          gencode();
                        else
                          fprintf(stderr, "No code generated.\n");
                      {}<<<<<<< driver.c
                        exit(nerr == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
                      {}=======
                        exit(!!nerr);
                      {}>>>>>>> 1.6
                      }

 Note how all non-overlapping modifications are incorporated in your working
 copy, and that the overlapping section is clearly marked with '<<<<<<<',
 '=======' and '>>>>>>>'.

 You resolve the conflict by editing the file, removing the markers and the
 erroneous line.  Suppose you end up with this file:

                      #include <stdlib.h>
                      #include <stdio.h>
                      int main(int argc,
                           char **argv)
                      {
                        init_scanner();
                        parse();
                        if (argc != 1)
                        {
                          fprintf(stderr, "tc: No args expected.\n");
                          exit(1);
                        }
                        if (nerr == 0)
                          gencode();
                        else
                          fprintf(stderr, "No code generated.\n");
                        exit(nerr == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
                      }

 You can now go ahead and commit this as revision 1.7.

                      $ cvs commit -m "Initialize scanner. Use symbolic exit values." driver.c
                      Checking in driver.c;
                      /usr/local/cvsroot/yoyodyne/tc/driver.c,v  <--  driver.c
                      new revision: 1.7; previous revision: 1.6
                      done

 For your protection, CVS will refuse to check in a file if a conflict occurred
 and you have not resolved the conflict.  Currently to resolve a conflict, you
 must change the timestamp on the file.  In previous versions of CVS, you also
 needed to insure that the file contains no conflict markers. Because your file
 may legitimately contain conflict markers (that is, occurrences of '>>>>>>> '
 at the start of a line that don't mark a conflict), the current version of CVS
 will print a warning and proceed to check in the file. If you use release 1.04
 or later of pcl-cvs (a GNU Emacs front-end for CVS) you can use an Emacs
 package called emerge to help you resolve conflicts. See the documentation for
 pcl-cvs.


ΓòÉΓòÉΓòÉ 11.4. Informing others about commits ΓòÉΓòÉΓòÉ

 It is often useful to inform others when you commit a new revision of a file.
 The '-i' option of the 'modules' file, or the 'loginfo' file, can be used to
 automate this process.  See modules. See loginfo.  You can use these features
 of CVS to, for instance, instruct CVS to mail a message to all developers, or
 post a message to a local newsgroup.


ΓòÉΓòÉΓòÉ 11.5. Several developers simultaneously attempting to run CVS ΓòÉΓòÉΓòÉ

 If several developers try to run CVS at the same time, one may get the
 following message:

                      [11:43:23] waiting for bach's lock in /usr/local/cvsroot/foo

 CVS will try again every 30 seconds, and either continue with the operation or
 print the message again, if it still needs to wait.  If a lock seems to stick
 around for an undue amount of time, find the person holding the lock and ask
 them about the cvs command they are running.  If they aren't running a cvs
 command, look in the repository directory mentioned in the message and remove
 files which they own whose names start with '#cvs.rfl', '#cvs.wfl', or
 '#cvs.lock'.

 Note that these locks are to protect CVS's internal data structures and have
 no relationship to the word lock in the sense used by RCS---which refers to
 reserved checkouts (see Multiple developers).

 Any number of people can be reading from a given repository at a time; only
 when someone is writing do the locks prevent other people from reading or
 writing.

 One might hope for the following property

                      If someone commits some changes in one cvs command,
                      then an update by someone else will either get all the
                      changes, or none of them.

 but CVS does not have this property.  For example, given the files

                      a/one.c
                      a/two.c
                      b/three.c
                      b/four.c

 if someone runs

                      cvs ci a/two.c b/three.c

 and someone else runs cvs update at the same time, the person running update
 might get only the change to 'b/three.c' and not the change to 'a/two.c'.


ΓòÉΓòÉΓòÉ 11.6. Mechanisms to track who is editing files ΓòÉΓòÉΓòÉ

 For many groups, use of CVS in its default mode is perfectly satisfactory.
 Users may sometimes go to check in a modification only to find that another
 modification has intervened, but they deal with it and proceed with their
 check in.  Other groups prefer to be able to know who is editing what files,
 so that if two people try to edit the same file they can choose to talk about
 who is doing what when rather than be surprised at check in time.  The
 features in this section allow such coordination, while retaining the ability
 of two developers to edit the same file at the same time.

 For maximum benefit developers should use cvs edit (not chmod) to make files
 read-write to edit them, and cvs release (not rm) to discard a working
 directory which is no longer in use, but CVS is not able to enforce this
 behavior.

 Setting a watch               Telling CVS to watch certain files
 Getting Notified              Telling CVS to notify you
 Editing files                 How to edit a file which is being watched
 Watch information             Information about who is watching and editing
 Watches Compatibility         Watches interact poorly with CVS 1.6 or earlier


ΓòÉΓòÉΓòÉ 11.6.1. Telling CVS to watch certain files ΓòÉΓòÉΓòÉ

 To enable the watch features, you first specify that certain files are to be
 watched.

 cvs watch on  [-lR] files ┬╖┬╖┬╖   (Command)

           Specify that developers should run cvs edit before editing files.
           CVS will create working copies of files read-only, to remind
           developers to run the cvs edit command before working on them.

           If files includes the name of a directory, CVS arranges to watch all
           files added to the corresponding repository directory, and sets a
           default for files added in the future; this allows the user to set
           notification policies on a per-directory basis.  The contents of the
           directory are processed recursively, unless the -l option is given.
           The -R option can be used to force recursion if the -l option is set
           in '~/.cvsrc' (see ~/.cvsrc).

           If files is omitted, it defaults to the current directory.

 cvs watch off  [-lR] files ┬╖┬╖┬╖   (Command)

           Do not provide notification about work on files.  CVS will create
           working copies of files read-write.

           The files and options are processed as for cvs watch on.


ΓòÉΓòÉΓòÉ 11.6.2. Telling CVS to notify you ΓòÉΓòÉΓòÉ

 You can tell CVS that you want to receive notifications about various actions
 taken on a file. You can do this without using cvs watch on for the file, but
 generally you will want to use cvs watch on, so that developers use the cvs
 edit command.

 cvs watch add  [-a action] [-lR] files ┬╖┬╖┬╖   (Command)

           Add the current user to the list of people to receive notification
           of work done on files.

           The -a option specifies what kinds of events CVS should notify the
           user about.  action is one of the following:

           edit
                     Another user has applied the cvs edit command (described
                     below) to a file.

           unedit
                     Another user has applied the cvs unedit command (described
                     below) or the cvs release command to a file, or has
                     deleted the file and allowed cvs update to recreate it.

           commit
                     Another user has committed changes to a file.

           all
                     All of the above.

           none
                     None of the above.  (This is useful with cvs edit,
                     described below.)

           The -a option may appear more than once, or not at all.  If omitted,
           the action defaults to all.

           The files and options are processed as for the cvs watch commands.

 cvs watch remove  [-a action] [-lR] files ┬╖┬╖┬╖   (Command)

           Remove a notification request established using cvs watch add; the
           arguments are the same.  If the -a option is present, only watches
           for the specified actions are removed.

 When the conditions exist for notification, CVS calls the 'notify'
 administrative file.  Edit 'notify' as one edits the other administrative
 files (see Intro administrative files).  This file follows the usual
 conventions for administrative files (see syntax), where each line is a
 regular expression followed by a command to execute.  The command should
 contain a single ocurrence of '%s' which will be replaced by the user to
 notify; the rest of the information regarding the notification will be
 supplied to the command on standard input.  The standard thing to put in the
 notify file is the single line:

                      ALL mail %s -s \"CVS notification\"

 This causes users to be notified by electronic mail. Note that if you set this
 up in the straightforward way, users receive notifications on the server
 machine. One could of course write a 'notify' script which directed
 notifications elsewhere, but to make this easy, CVS allows you to associate a
 notification address for each user.  To do so create a file 'users' in
 'CVSROOT' with a line for each user in the format user:value.  Then instead of
 passing the name of the user to be notified to 'notify', CVS will pass the
 value (normally an email address on some other machine).

 CVS does not notify you for your own changes. Currently this check is done
 based on whether the user name of the person taking the action which triggers
 notification matches the user name of the person getting notification.  In
 fact, in general, the watches features only track one edit by each user.  It
 probably would be more useful if watches tracked each working directory
 separately, so this behavior might be worth changing.


ΓòÉΓòÉΓòÉ 11.6.3. How to edit a file which is being watched ΓòÉΓòÉΓòÉ

 Since a file which is being watched is checked out read-only, you cannot
 simply edit it.  To make it read-write, and inform others that you are
 planning to edit it, use the cvs edit command.  Some systems call this a
 checkout, but CVS uses that term for obtaining a copy of the sources (see
 Getting the source), an operation which those systems call a get or a fetch.

 cvs edit  [options] files ┬╖┬╖┬╖   (Command)

           Prepare to edit the working files files.  CVS makes the files
           read-write, and notifies users who have requested edit notification
           for any of files.

           The cvs edit command accepts the same options as the cvs watch add
           command, and establishes a temporary watch for the user on files;
           CVS will remove the watch when files are unedited or committed.  If
           the user does not wish to receive notifications, she should specify
           -a none.

           The files and options are processed as for the cvs watch commands.

           Caution: If the PreservePermissions option is enabled in the
           repository (see config), CVS will not change the permissions on any
           of the files.  The reason for this change is to ensure that using
           'cvs edit' does not interfere with the ability to store file
           permissions in the CVS repository.

 Normally when you are done with a set of changes, you use the cvs commit
 command, which checks in your changes and returns the watched files to their
 usual read-only state.  But if you instead decide to abandon your changes, or
 not to make any changes, you can use the cvs unedit command.

 cvs unedit  [-lR] files ┬╖┬╖┬╖   (Command)

           Abandon work on the working files files, and revert them to the
           repository versions on which they are based.  CVS makes those files
           read-only for which users have requested notification using cvs
           watch on.  CVS notifies users who have requested unedit notification
           for any of files.

           The files and options are processed as for the cvs watch commands.

           If watches are not in use, the unedit command probably does not
           work, and the way to revert to the repository version is to remove
           the file and then use cvs update to get a new copy.  The meaning is
           not precisely the same; removing and updating may also bring in some
           changes which have been made in the repository since the last time
           you updated.

 When using client/server CVS, you can use the cvs edit and cvs unedit commands
 even if CVS is unable to succesfully communicate with the server; the
 notifications will be sent upon the next successful CVS command.


ΓòÉΓòÉΓòÉ 11.6.4. Information about who is watching and editing ΓòÉΓòÉΓòÉ

 cvs watchers  [-lR] files ┬╖┬╖┬╖   (Command)

           List the users currently watching changes to files.  The report
           includes the files being watched, and the mail address of each
           watcher.

           The files and options are processed as for the cvs watch commands.

 cvs editors  [-lR] files ┬╖┬╖┬╖   (Command)

           List the users currently working on files.  The report includes the
           mail address of each user, the time when the user began working with
           the file, and the host and path of the working directory containing
           the file.

           The files and options are processed as for the cvs watch commands.


ΓòÉΓòÉΓòÉ 11.6.5. Using watches with old versions of CVS ΓòÉΓòÉΓòÉ

 If you use the watch features on a repository, it creates 'CVS' directories in
 the repository and stores the information about watches in that directory. If
 you attempt to use CVS 1.6 or earlier with the repository, you get an error
 message such as the following (all on one line):

                      cvs update: cannot open CVS/Entries for reading:
                      No such file or directory

 and your operation will likely be aborted.  To use the watch features, you
 must upgrade all copies of CVS which use that repository in local or server
 mode.  If you cannot upgrade, use the watch off and watch remove commands to
 remove all watches, and that will restore the repository to a state which CVS
 1.6 can cope with.


ΓòÉΓòÉΓòÉ 11.7. Choosing between reserved or unreserved checkouts ΓòÉΓòÉΓòÉ

 Reserved and unreserved checkouts each have pros and cons.  Let it be said
 that a lot of this is a matter of opinion or what works given different
 groups' working styles, but here is a brief description of some of the issues.
 There are many ways to organize a team of developers.  CVS does not try to
 enforce a certain organization.  It is a tool that can be used in several
 ways.

 Reserved checkouts can be very counter-productive.  If two persons want to
 edit different parts of a file, there may be no reason to prevent either of
 them from doing so.  Also, it is common for someone to take out a lock on a
 file, because they are planning to edit it, but then forget to release the
 lock.

 People, especially people who are familiar with reserved checkouts, often
 wonder how often conflicts occur if unreserved checkouts are used, and how
 difficult they are to resolve.  The experience with many groups is that they
 occur rarely and usually are relatively straightforward to resolve.

 The rarity of serious conflicts may be surprising, until one realizes that
 they occur only when two developers disagree on the proper design for a given
 section of code; such a disagreement suggests that the team has not been
 communicating properly in the first place.  In order to collaborate under any
 source management regimen, developers must agree on the general design of the
 system; given this agreement, overlapping changes are usually straightforward
 to merge.

 In some cases unreserved checkouts are clearly inappropriate.  If no merge
 tool exists for the kind of file you are managing (for example word processor
 files or files edited by Computer Aided Design programs), and it is not
 desirable to change to a program which uses a mergeable data format, then
 resolving conflicts is going to be unpleasant enough that you generally will
 be better off to simply avoid the conflicts instead, by using reserved
 checkouts.

 The watches features described above in Watches can be considered to be an
 intermediate model between reserved checkouts and unreserved checkouts.  When
 you go to edit a file, it is possible to find out who else is editing it.  And
 rather than having the system simply forbid both people editing the file, it
 can tell you what the situation is and let you figure out whether it is a
 problem in that particular case or not. Therefore, for some groups it can be
 considered the best of both the reserved checkout and unreserved checkout
 worlds.


ΓòÉΓòÉΓòÉ 12. Revision management ΓòÉΓòÉΓòÉ

 If you have read this far, you probably have a pretty good grasp on what CVS
 can do for you.  This chapter talks a little about things that you still have
 to decide.

 If you are doing development on your own using CVS you could probably skip
 this chapter.  The questions this chapter takes up become more important when
 more than one person is working in a repository.

 When to commit                Some discussion on the subject


ΓòÉΓòÉΓòÉ 12.1. When to commit? ΓòÉΓòÉΓòÉ

 Your group should decide which policy to use regarding commits.  Several
 policies are possible, and as your experience with CVS grows you will probably
 find out what works for you.

 If you commit files too quickly you might commit files that do not even
 compile.  If your partner updates his working sources to include your buggy
 file, he will be unable to compile the code.  On the other hand, other persons
 will not be able to benefit from the improvements you make to the code if you
 commit very seldom, and conflicts will probably be more common.

 It is common to only commit files after making sure that they can be compiled.
 Some sites require that the files pass a test suite.  Policies like this can
 be enforced using the commitinfo file (see commitinfo), but you should think
 twice before you enforce such a convention.  By making the development
 environment too controlled it might become too regimented and thus
 counter-productive to the real goal, which is to get software written.


ΓòÉΓòÉΓòÉ 13. Keyword substitution ΓòÉΓòÉΓòÉ

 As long as you edit source files inside your working copy of a module you can
 always find out the state of your files via 'cvs status' and 'cvs log'. But as
 soon as you export the files from your development environment it becomes
 harder to identify which revisions they are.

 CVS can use a mechanism known as keyword substitution (or keyword expansion)
 to help identifying the files.  Embedded strings of the form $keyword$ and
 $keyword:┬╖┬╖┬╖$ in a file are replaced with strings of the form $keyword:value$
 whenever you obtain a new revision of the file.

 Keyword list                  Keywords
 Using keywords                Using keywords
 Avoiding substitution         Avoiding substitution
 Substitution modes            Substitution modes
 Log keyword                   Problems with the $Log$ keyword.


ΓòÉΓòÉΓòÉ 13.1. Keyword List ΓòÉΓòÉΓòÉ

 This is a list of the keywords:

 $Author$
           The login name of the user who checked in the revision.

 $Date$
           The date and time (UTC) the revision was checked in.

 $Header$
           A standard header containing the full pathname of the RCS file, the
           revision number, the date (UTC), the author, the state, and the
           locker (if locked).  Files will normally never be locked when you
           use CVS.

 $Id$
           Same as $Header$}, except that the RCS filename is without a path.

 $Name$
           Tag name used to check out this file.

 $Locker$
           The login name of the user who locked the revision (empty if not
           locked, and thus almost always useless when you are using CVS).

 $Log$
           The log message supplied during commit, preceded by a header
           containing the RCS filename, the revision number, the author, and
           the date (UTC).  Existing log messages are not replaced.  Instead,
           the new log message is inserted after $Log:┬╖┬╖┬╖$}. Each new line is
           prefixed with the same string which precedes the $Log keyword.  For
           example, if the file contains

                       /* Here is what people have been up to:
                        *
                        * ${}Log: frob.c,v $
                        * Revision 1.1  1997/01/03 14:23:51  joe
                        * Add the superfrobnicate option
                        *
                        */

 then additional lines which are added when expanding the $Log keyword will be
 preceded by '  * '. Unlike previous versions of CVS and RCS, the comment
 leader from the RCS file is not used. The $Log keyword is useful for
 accumulating a complete change log in a source file, but for several reasons
 it can be problematic. See Log keyword.

 $RCSfile$
           The name of the RCS file without a path.

 $Revision$
           The revision number assigned to the revision.

 $Source$
           The full pathname of the RCS file.

 $State$
           The state assigned to the revision.  States can be assigned with cvs
           admin -s---see admin options.


ΓòÉΓòÉΓòÉ 13.2. Using keywords ΓòÉΓòÉΓòÉ

 To include a keyword string you simply include the relevant text string, such
 as $Id$}, inside the file, and commit the file.  CVS will automatically expand
 the string as part of the commit operation.

 It is common to embed the $Id$} string in the source files so that it gets
 passed through to generated files.  For example, if you are managing computer
 program source code, you might include a variable which is initialized to
 contain that string. Or some C compilers may provide a #pragma ident
 directive.  Or a document management system might provide a way to pass a
 string through to generated files.

 The ident command (which is part of the RCS package) can be used to extract
 keywords and their values from a file.  This can be handy for text files, but
 it is even more useful for extracting keywords from binary files.

                      $ ident samp.c
                      samp.c:
                         ${}Id: samp.c,v 1.5 1993/10/19 14:57:32 ceder Exp $
                      $ gcc samp.c
                      $ ident a.out
                      a.out:
                         ${}Id: samp.c,v 1.5 1993/10/19 14:57:32 ceder Exp $

 SCCS is another popular revision control system. It has a command, what, which
 is very similar to ident and used for the same purpose.  Many sites without
 RCS have SCCS.  Since what looks for the character sequence @(#) it is easy to
 include keywords that are detected by either command.  Simply prefix the RCS
 keyword with the magic SCCS phrase, like this:

                      static char *id="@(#) ${}Id: ab.c,v 1.5 1993/10/19 14:57:32 ceder Exp $";


ΓòÉΓòÉΓòÉ 13.3. Avoiding substitution ΓòÉΓòÉΓòÉ

 Keyword substitution has its disadvantages.  Sometimes you might want the
 literal text string '$'Author$} to appear inside a file without CVS
 interpreting it as a keyword and expanding it into something like '$'Author:
 ceder $}.

 There is unfortunately no way to selectively turn off keyword substitution.
 You can use '-ko' (see Substitution modes) to turn off keyword substitution
 entirely.

 In many cases you can avoid using keywords in the source, even though they
 appear in the final product.  For example, the source for this manual contains
 '$@asis{}Author$' whenever the text '$'Author$} should appear.  In nroff and
 troff you can embed the null-character \& inside the keyword for a similar
 effect.


ΓòÉΓòÉΓòÉ 13.4. Substitution modes ΓòÉΓòÉΓòÉ

 Each file has a stored default substitution mode, and each working directory
 copy of a file also has a substitution mode.  The former is set by the '-k'
 option to cvs add and cvs admin; the latter is set by the '-k' or '-A' options
 to cvs checkout or cvs update.  cvs diff also has a '-k' option.  For some
 examples, see Binary files. The modes available are:

 '-kkv'
           Generate keyword strings using the default form, e.g. $Revision: 5.7
           $} for the Revision keyword.

 '-kkvl'
           Like '-kkv', except that a locker's name is always inserted if the
           given revision is currently locked. This option is normally not
           useful when CVS is used.

 '-kk'
           Generate only keyword names in keyword strings; omit their values.
           For example, for the Revision keyword, generate the string
           $Revision$} instead of $Revision: 5.7 $}.  This option is useful to
           ignore differences due to keyword substitution when comparing
           different revisions of a file.

 '-ko'
           Generate the old keyword string, present in the working file just
           before it was checked in.  For example, for the Revision keyword,
           generate the string $Revision: 1.1 $} instead of $Revision: 5.7 $}
           if that is how the string appeared when the file was checked in.

 '-kb'
           Like '-ko', but also inhibit conversion of line endings between the
           canonical form in which they are stored in the repository (linefeed
           only), and the form appropriate to the operating system in use on
           the client.  For systems, like unix, which use linefeed only to
           terminate lines, this is the same as '-ko'.  For more information on
           binary files, see Binary files.

 '-kv'
           Generate only keyword values for keyword strings.  For example, for
           the Revision keyword, generate the string 5.7 instead of $Revision:
           5.7 $}. This can help generate files in programming languages where
           it is hard to strip keyword delimiters like $Revision: $} from a
           string.  However, further keyword substitution cannot be performed
           once the keyword names are removed, so this option should be used
           with care.

           One often would like to use '-kv' with cvs export---see export.  But
           be aware that doesn't handle an export containing binary files
           correctly.


ΓòÉΓòÉΓòÉ 13.5. Problems with the $Log$ keyword. ΓòÉΓòÉΓòÉ

 The $Log$} keyword is somewhat controversial.  As long as you are working on
 your development system the information is easily accessible even if you do
 not use the $Log$} keyword---just do a cvs log.  Once you export the file the
 history information might be useless anyhow.

 A more serious concern is that CVS is not good at handling $Log$} entries when
 a branch is merged onto the main trunk.  Conflicts often result from the
 merging operation. People also tend to "fix" the log entries in the file
 (correcting spelling mistakes and maybe even factual errors).  If that is done
 the information from cvs log will not be consistent with the information
 inside the file.  This may or may not be a problem in real life.

 It has been suggested that the $Log$} keyword should be inserted last in the
 file, and not in the files header, if it is to be used at all. That way the
 long list of change messages will not interfere with everyday source file
 browsing.


ΓòÉΓòÉΓòÉ 14. Tracking third-party sources ΓòÉΓòÉΓòÉ

 If you modify a program to better fit your site, you probably want to include
 your modifications when the next release of the program arrives.  CVS can help
 you with this task.

 In the terminology used in CVS, the supplier of the program is called a
 vendor.  The unmodified distribution from the vendor is checked in on its own
 branch, the vendor branch.  CVS reserves branch 1.1.1 for this use.

 When you modify the source and commit it, your revision will end up on the
 main trunk.  When a new release is made by the vendor, you commit it on the
 vendor branch and copy the modifications onto the main trunk.

 Use the import command to create and update the vendor branch.  When you
 import a new file, the vendor branch is made the `head' revision, so anyone
 that checks out a copy of the file gets that revision.  When a local
 modification is committed it is placed on the main trunk, and made the `head'
 revision.

 First import                  Importing a module for the first time
 Update imports                Updating a module with the import command
 Reverting local changes       Reverting a module to the latest vendor release
 Binary files in imports       Binary files require special handling
 Keywords in imports           Keyword substitution might be undesirable
 Multiple vendor branches      What if you get sources from several places?


ΓòÉΓòÉΓòÉ 14.1. Importing a module for the first time ΓòÉΓòÉΓòÉ

 Use the import command to check in the sources for the first time.  When you
 use the import command to track third-party sources, the vendor tag and
 release tags are useful.  The vendor tag is a symbolic name for the branch
 (which is always 1.1.1, unless you use the '-b branch' flag---See Multiple
 vendor branches.).  The release tags are symbolic names for a particular
 release, such as 'FSF_0_04'.

 Note that import does not change the directory in which you invoke it.  In
 particular, it does not set up that directory as a CVS working directory; if
 you want to work with the sources import them first and then check them out
 into a different directory (see Getting the source).

 Suppose you have the sources to a program called wdiff in a directory
 'wdiff-0.04', and are going to make private modifications that you want to be
 able to use even when new releases are made in the future.  You start by
 importing the source to your repository:

                      $ cd wdiff-0.04
                      $ cvs import -m "Import of FSF v. 0.04" fsf/wdiff FSF_DIST WDIFF_0_04

 The vendor tag is named 'FSF_DIST' in the above example, and the only release
 tag assigned is 'WDIFF_0_04'.


ΓòÉΓòÉΓòÉ 14.2. Updating a module with the import command ΓòÉΓòÉΓòÉ

 When a new release of the source arrives, you import it into the repository
 with the same import command that you used to set up the repository in the
 first place.  The only difference is that you specify a different release tag
 this time.

                      $ tar xfz wdiff-0.05.tar.gz
                      $ cd wdiff-0.05
                      $ cvs import -m "Import of FSF v. 0.05" fsf/wdiff FSF_DIST WDIFF_0_05

 For files that have not been modified locally, the newly created revision
 becomes the head revision.  If you have made local changes, import will warn
 you that you must merge the changes into the main trunk, and tell you to use
 'checkout -j' to do so.

                      $ cvs checkout -jFSF_DIST:yesterday -jFSF_DIST wdiff

 The above command will check out the latest revision of 'wdiff', merging the
 changes made on the vendor branch 'FSF_DIST' since yesterday into the working
 copy.  If any conflicts arise during the merge they should be resolved in the
 normal way (see Conflicts example).  Then, the modified files may be
 committed.

 Using a date, as suggested above, assumes that you do not import more than one
 release of a product per day. If you do, you can always use something like
 this instead:

                      $ cvs checkout -jWDIFF_0_04 -jWDIFF_0_05 wdiff

 In this case, the two above commands are equivalent.


ΓòÉΓòÉΓòÉ 14.3. Reverting to the latest vendor release ΓòÉΓòÉΓòÉ

 You can also revert local changes completely and return to the latest vendor
 release by changing the `head' revision back to the vendor branch on all
 files.  For example, if you have a checked-out copy of the sources in
 '~/work.d/wdiff', and you want to revert to the vendor's version for all the
 files in that directory, you would type:

                      $ cd ~/work.d/wdiff
                      $ cvs admin -bWDIFF .

 You must specify the '-bWDIFF' without any space after the '-b'.  See admin
 options.


ΓòÉΓòÉΓòÉ 14.4. How to handle binary files with cvs import ΓòÉΓòÉΓòÉ

 Use the '-k' wrapper option to tell import which files are binary.  See
 Wrappers.


ΓòÉΓòÉΓòÉ 14.5. How to handle keyword substitution with cvs import ΓòÉΓòÉΓòÉ

 The sources which you are importing may contain keywords (see Keyword
 substitution).  For example, the vendor may use CVS or some other system which
 uses similar keyword expansion syntax.  If you just import the files in the
 default fashion, then the keyword expansions supplied by the vendor will be
 replaced by keyword expansions supplied by your own copy of CVS.  It may be
 more convenient to maintain the expansions supplied by the vendor, so that
 this information can supply information about the sources that you imported
 from the vendor.

 To maintain the keyword expansions supplied by the vendor, supply the '-ko'
 option to cvs import the first time you import the file. This will turn off
 keyword expansion for that file entirely, so if you want to be more selective
 you'll have to think about what you want and use the '-k' option to cvs update
 or cvs admin as appropriate.


ΓòÉΓòÉΓòÉ 14.6. Multiple vendor branches ΓòÉΓòÉΓòÉ

 All the examples so far assume that there is only one vendor from which you
 are getting sources.  In some situations you might get sources from a variety
 of places.  For example, suppose that you are dealing with a project where
 many different people and teams are modifying the software.  There are a
 variety of ways to handle this, but in some cases you have a bunch of source
 trees lying around and what you want to do more than anything else is just to
 all put them in CVS so that you at least have them in one place.

 For handling situations in which there may be more than one vendor, you may
 specify the '-b' option to cvs import.  It takes as an argument the vendor
 branch to import to.  The default is '-b 1.1.1'.

 For example, suppose that there are two teams, the red team and the blue team,
 that are sending you sources. You want to import the red team's efforts to
 branch 1.1.1 and use the vendor tag RED.  You want to import the blue team's
 efforts to branch 1.1.3 and use the vendor tag BLUE.  So the commands you
 might use are:

                      $ cvs import dir RED RED_1-0
                      $ cvs import -b 1.1.3 dir BLUE BLUE_1-5

 Note that if your vendor tag does not match your '-b' option, CVS will not
 detect this case!  For example,

                      $ cvs import -b 1.1.3 dir RED RED_1-0

 Be careful; this kind of mismatch is sure to sow confusion or worse.  I can't
 think of a useful purpose for the ability to specify a mismatch here, but if
 you discover such a use, don't.  CVS is likely to make this an error in some
 future release.


ΓòÉΓòÉΓòÉ 15. How your build system interacts with CVS ΓòÉΓòÉΓòÉ

 As mentioned in the introduction, CVS does not contain software for building
 your software from source code.  This section describes how various aspects of
 your build system might interact with CVS.

 One common question, especially from people who are accustomed to RCS, is how
 to make their build get an up to date copy of the sources.  The answer to this
 with CVS is two-fold.  First of all, since CVS itself can recurse through
 directories, there is no need to modify your 'Makefile' (or whatever
 configuration file your build tool uses) to make sure each file is up to date.
 Instead, just use two commands, first cvs -q update and then make or whatever
 the command is to invoke your build tool.  Secondly, you do not necessarily
 want to get a copy of a change someone else made until you have finished your
 own work.  One suggested approach is to first update your sources, then
 implement, build and test the change you were thinking of, and then commit
 your sources (updating first if necessary).  By periodically (in between
 changes, using the approach just described) updating your entire tree, you
 ensure that your sources are sufficiently up to date.

 One common need is to record which versions of which source files went into a
 particular build.  This kind of functionality is sometimes called bill of
 materials or something similar.  The best way to do this with CVS is to use
 the tag command to record which versions went into a given build (see Tags).

 Using CVS in the most straightforward manner possible, each developer will
 have a copy of the entire source tree which is used in a particular build.  If
 the source tree is small, or if developers are geographically dispersed, this
 is the preferred solution.  In fact one approach for larger projects is to
 break a project down into smaller separately-compiled subsystems, and arrange
 a way of releasing them internally so that each developer need check out only
 those subsystems which are they are actively working on.

 Another approach is to set up a structure which allows developers to have
 their own copies of some files, and for other files to access source files
 from a central location.  Many people have come up with some such a system
 using features such as the symbolic link feature found in many operating
 systems, or the VPATH feature found in many versions of make.  One build tool
 which is designed to help with this kind of thing is Odin (see
 ftp://ftp.cs.colorado.edu/pub/distribs/odin).


ΓòÉΓòÉΓòÉ 16. Special Files ΓòÉΓòÉΓòÉ

 In normal circumstances, CVS works only with regular files.  Every file in a
 project is assumed to be persistent; it must be possible to open, read and
 close them; and so on.  CVS also ignores file permissions and ownerships,
 leaving such issues to be resolved by the developer at installation time.  In
 other words, it is not possible to "check in" a device into a repository; if
 the device file cannot be opened, CVS will refuse to handle it.  Files also
 lose their ownerships and permissions during repository transactions.

 If the configuration variable PreservePermissions (see config) is set in the
 repository, CVS will save the following file characteristics in the
 repository:

     user and group ownership

     permissions

     major and minor device numbers

     symbolic links

     hard link structure

 Using the PreservePermissions option affects the behavior of CVS in several
 ways.  First, some of the new operations supported by CVS are not accessible
 to all users.  In particular, file ownership and special file characteristics
 may only be changed by the superuser.  When the PreservePermissions
 configuration variable is set, therefore, users will have to be `root' in
 order to perform CVS operations.

 When PreservePermissions is in use, some CVS operations (such as 'cvs status')
 will not recognize a file's hard link structure, and so will emit spurious
 warnings about mismatching hard links. The reason is that CVS's internal
 structure does not make it easy for these operations to collect all the
 necessary data about hard links, so they check for file conflicts with
 inaccurate data.

 A more subtle difference is that CVS considers a file to have changed only if
 its contents have changed (specifically, if the modification time of the
 working file does not match that of the repository's file). Therefore, if only
 the permissions, ownership or hard linkage have changed, or if a device's
 major or minor numbers have changed, CVS will not notice.  In order to commit
 such a change to the repository, you must force the commit with 'cvs commit
 -f'.  This also means that if a file's permissions have changed and the
 repository file is newer than the working copy, performing 'cvs update' will
 silently change the permissions on the working copy.

 Changing hard links in a CVS repository is particularly delicate.  Suppose
 that file 'foo' is linked to file 'old', but is later relinked to file 'new'.
 You can wind up in the unusual situation where, although 'foo', 'old' and
 'new' have all had their underlying link patterns changed, only 'foo' and
 'new' have been modified, so 'old' is not considered a candidate for checking
 in.  It can be very easy to produce inconsistent results this way.  Therefore,
 we recommend that when it is important to save hard links in a repository, the
 prudent course of action is to touch any file whose linkage or status has
 changed since the last checkin.  Indeed, it may be wise to touch * before each
 commit in a directory with complex hard link structures.

 It is worth noting that only regular files may be merged, for reasons that
 hopefully are obvious.  If 'cvs update' or 'cvs checkout -j' attempts to merge
 a symbolic link with a regular file, or two device files for different kinds
 of devices, CVS will report a conflict and refuse to perform the merge.  At
 the same time, 'cvs diff' will not report any differences between these files,
 since no meaningful textual comparisons can be made on files which contain no
 text.

 The PreservePermissions features do not work with client/server CVS.  Another
 limitation is that hard links must be to other files within the same
 directory; hard links across directories are not supported.


ΓòÉΓòÉΓòÉ 17. Guide to CVS commands ΓòÉΓòÉΓòÉ

 This appendix describes the overall structure of CVS commands, and describes
 some commands in detail (others are described elsewhere; for a quick reference
 to CVS commands, see Invoking CVS).

 Structure                     Overall structure of CVS commands
 Exit status                   Indicating CVS's success or failure
 ~/.cvsrc                      Default options with the ~/.csvrc file
 Global options                Options you give to the left of cvs_command
 Common options                Options you give to the right of cvs_command
 admin                         Administration
 checkout                      Checkout sources for editing
 commit                        Check files into the repository
 diff                          Show differences between revisions
 export                        Export sources from CVS, similar to checkout
 history                       Show status of files and users
 import                        Import sources into CVS, using vendor branches
 log                           Show log messages for files
 rdiff                         'patch' format diffs between releases
 release                       Indicate that a Module is no longer in use
 rtag                          Add a tag to a module
 tag                           Add a tag to checked out version
 update                        Bring work tree in sync with repository


ΓòÉΓòÉΓòÉ 17.1. Overall structure of CVS commands ΓòÉΓòÉΓòÉ

 The overall format of all CVS commands is:

                      cvs [ cvs_options ] cvs_command [ command_options ] [ command_args ]

 cvs
           The name of the CVS program.

 cvs_options
           Some options that affect all sub-commands of CVS.  These are
           described below.

 cvs_command
           One of several different sub-commands.  Some of the commands have
           aliases that can be used instead; those aliases are noted in the
           reference manual for that command.  There are only two situations
           where you may omit 'cvs_command': 'cvs -H' elicits a list of
           available commands, and 'cvs -v' displays version information on CVS
           itself.

 command_options
           Options that are specific for the command.

 command_args
           Arguments to the commands.

 There is unfortunately some confusion between cvs_options and command_options.
 '-l', when given as a cvs_option, only affects some of the commands.  When it
 is given as a command_option is has a different meaning, and is accepted by
 more commands.  In other words, do not take the above categorization too
 seriously.  Look at the documentation instead.


ΓòÉΓòÉΓòÉ 17.2. CVS's exit status ΓòÉΓòÉΓòÉ

 CVS can indicate to the calling environment whether it succeeded or failed by
 setting its exit status. The exact way of testing the exit status will vary
 from one operating system to another.  For example in a unix shell script the
 '$?' variable will be 0 if the last command returned a successful exit status,
 or greater than 0 if the exit status indicated failure.

 If CVS is successful, it returns a successful status; if there is an error, it
 prints an error message and returns a failure status.  The one exception to
 this is the cvs diff command.  It will return a successful status if it found
 no differences, or a failure status if there were differences or if there was
 an error.  Because this behavior provides no good way to detect errors, in the
 future it is possible that cvs diff will be changed to behave like the other
 CVS commands.


ΓòÉΓòÉΓòÉ 17.3. Default options and the ~/.cvsrc file ΓòÉΓòÉΓòÉ

 There are some command_options that are used so often that you might have set
 up an alias or some other means to make sure you always specify that option.
 One example (the one that drove the implementation of the '.cvsrc' support,
 actually) is that many people find the default output of the 'diff' command to
 be very hard to read, and that either context diffs or unidiffs are much
 easier to understand.

 The '~/.cvsrc' file is a way that you can add default options to cvs_commands
 within cvs, instead of relying on aliases or other shell scripts.

 The format of the '~/.cvsrc' file is simple.  The file is searched for a line
 that begins with the same name as the cvs_command being executed.  If a match
 is found, then the remainder of the line is split up (at whitespace
 characters) into separate options and added to the command arguments before
 any options from the command line.

 If a command has two names (e.g., checkout and co), the official name, not
 necessarily the one used on the command line, will be used to match against
 the file.  So if this is the contents of the user's '~/.cvsrc' file:

                      log -N
                      diff -u
                      update -P
                      checkout -P

 the command 'cvs checkout foo' would have the '-P' option added to the
 arguments, as well as 'cvs co foo'.

 With the example file above, the output from 'cvs diff foobar' will be in
 unidiff format.  'cvs diff -c foobar' will provide context diffs, as usual.
 Getting "old" format diffs would be slightly more complicated, because diff
 doesn't have an option to specify use of the "old" format, so you would need
 'cvs -f diff foobar'.

 In place of the command name you can use cvs to specify global options (see
 Global options).  For example the following line in '.cvsrc'

                      cvs -z6

 causes CVS to use compression level 6.


ΓòÉΓòÉΓòÉ 17.4. Global options ΓòÉΓòÉΓòÉ

 The available 'cvs_options' (that are given to the left of 'cvs_command') are:

 --allow-root=rootdir
           Specify legal CVSROOT directory.  See Password authentication
           server.

 -a
           Authenticate all communication between the client and the server.
           Only has an effect on the CVS client. As of this writing, this is
           only implemented when using a GSSAPI connection (see GSSAPI
           authenticated). Authentication prevents certain sorts of attacks
           involving hijacking the active TCP connection. Enabling
           authentication does not enable encryption.

 -b bindir
           In CVS 1.9.18 and older, this specified that RCS programs are in the
           bindir directory. Current versions of CVS do not run RCS programs;
           for compatibility this option is accepted, but it does nothing.

 -T tempdir
           Use tempdir as the directory where temporary files are located.
           Overrides the setting of the $TMPDIR environment variable and any
           precompiled directory.  This parameter should be specified as an
           absolute pathname.

 -d cvs_root_directory
           Use cvs_root_directory as the root directory pathname of the
           repository.  Overrides the setting of the $CVSROOT environment
           variable.  See Repository.

 -e editor
           Use editor to enter revision log information.  Overrides the setting
           of the $CVSEDITOR and $EDITOR environment variables.  For more
           information, see Committing your changes.

 -f
           Do not read the '~/.cvsrc' file.  This option is most often used
           because of the non-orthogonality of the CVS option set.  For
           example, the 'cvs log' option '-N' (turn off display of tag names)
           does not have a corresponding option to turn the display on.  So if
           you have '-N' in the '~/.cvsrc' entry for 'log', you may need to use
           '-f' to show the tag names.

 -H

 --help
           Display usage information about the specified 'cvs_command' (but do
           not actually execute the command).  If you don't specify a command
           name, 'cvs -H' displays overall help for CVS, including a list of
           other help options.

 -l
           Do not log the 'cvs_command' in the command history (but execute it
           anyway).  See history, for information on command history.

 -n
           Do not change any files.  Attempt to execute the 'cvs_command', but
           only to issue reports; do not remove, update, or merge any existing
           files, or create any new files.

           Note that CVS will not necessarily produce exactly the same output
           as without '-n'.  In some cases the output will be the same, but in
           other cases CVS will skip some of the processing that would have
           been required to produce the exact same output.

 -Q
           Cause the command to be really quiet; the command will only generate
           output for serious problems.

 -q
           Cause the command to be somewhat quiet; informational messages, such
           as reports of recursion through subdirectories, are suppressed.

 -r
           Make new working files read-only.  Same effect as if the $CVSREAD
           environment variable is set (see Environment variables).  The
           default is to make working files writable, unless watches are on
           (see Watches).

 -s variable=value
           Set a user variable (see Variables).

 -t
           Trace program execution; display messages showing the steps of CVS
           activity.  Particularly useful with '-n' to explore the potential
           impact of an unfamiliar command.

 -v

 --version
           Display version and copyright information for CVS.

 -w
           Make new working files read-write.  Overrides the setting of the
           $CVSREAD environment variable. Files are created read-write by
           default, unless $CVSREAD is set or '-r' is given.

 -x
           Encrypt all communication between the client and the server.  Only
           has an effect on the CVS client.  As of this writing, this is only
           implemented when using a GSSAPI connection (see GSSAPI
           authenticated) or a Kerberos connection (see Kerberos
           authenticated). Enabling encryption implies that message traffic is
           also authenticated.  Encryption support is not available by default;
           it must be enabled using a special configure option,
           '--enable-encryption', when you build CVS.

 -z gzip-level
           Set the compression level.  Only has an effect on the CVS client.


ΓòÉΓòÉΓòÉ 17.5. Common command options ΓòÉΓòÉΓòÉ

 This section describes the 'command_options' that are available across several
 CVS commands.  These options are always given to the right of 'cvs_command'.
 Not all commands support all of these options; each option is only supported
 for commands where it makes sense. However, when a command has one of these
 options you can almost always count on the same behavior of the option as in
 other commands.  (Other command options, which are listed with the individual
 commands, may have different behavior from one CVS command to the other).

 Warning: the 'history' command is an exception; it supports many options that
 conflict even with these standard options.

 -D date_spec
           Use the most recent revision no later than date_spec. date_spec is a
           single argument, a date description specifying a date in the past.

           The specification is sticky when you use it to make a private copy
           of a source file; that is, when you get a working file using '-D',
           CVS records the date you specified, so that further updates in the
           same directory will use the same date (for more information on
           sticky tags/dates, see Sticky tags).

           '-D' is available with the checkout, diff, export, history, rdiff,
           rtag, and update commands. (The history command uses this option in
           a slightly different way; see history options).

           A wide variety of date formats are supported by CVS.  The most
           standard ones are ISO8601 (from the International Standards
           Organization) and the Internet e-mail standard (specified in RFC822
           as amended by RFC1123).

           ISO8601 dates have many variants but a few examples are:

                      1972-09-24
                      1972-09-24 20:05
 For more details about ISO8601 dates, see:

                      http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html
 In addition to the dates allowed in Internet e-mail itself, CVS also allows
 some of the fields to be omitted.  For example:

                      24 Sep 1972 20:05
                      24 Sep

 The date is interpreted as being in the local timezone, unless a specific
 timezone is specified.

 These two date formats are preferred.  However, CVS currently accepts a wide
 variety of other date formats.  They are intentionally not documented here in
 any detail, and future versions of CVS might not accept all of them. One such
 format is month/day/year.  This may confuse people who are accustomed to
 having the month and day in the other order; '1/4/96' is January 4, not April
 1.

 Remember to quote the argument to the '-D' flag so that your shell doesn't
 interpret spaces as argument separators.  A command using the '-D' flag can
 look like this:

                      $ cvs diff -D "1 hour ago" cvs.texinfo

 -f
           When you specify a particular date or tag to CVS commands, they
           normally ignore files that do not contain the tag (or did not exist
           prior to the date) that you specified.  Use the '-f' option if you
           want files retrieved even when there is no match for the tag or
           date.  (The most recent revision of the file will be used).

           '-f' is available with these commands: annotate, checkout, export,
           rdiff, rtag, and update.

           Warning:  The commit and remove commands also have a '-f' option,
           but it has a different behavior for those commands.  See commit
           options, and Removing files.

 -k kflag
           Alter the default processing of keywords. See Keyword substitution,
           for the meaning of kflag.  Your kflag specification is sticky when
           you use it to create a private copy of a source file; that is, when
           you use this option with the checkout or update commands, CVS
           associates your selected kflag with the file, and continues to use
           it with future update commands on the same file until you specify
           otherwise.

           The '-k' option is available with the add, checkout, diff, import
           and update commands.

 -l
           Local; run only in current working directory, rather than recursing
           through subdirectories.

           Warning: this is not the same as the overall 'cvs -l' option, which
           you can specify to the left of a cvs command!

           Available with the following commands: annotate, checkout, commit,
           diff, edit, editors, export, log, rdiff, remove, rtag, status, tag,
           unedit, update, watch, and watchers.

 -m message
           Use message as log information, instead of invoking an editor.

           Available with the following commands: add, commit and import.

 -n
           Do not run any checkout/commit/tag program.  (A program can be
           specified to run on each of these activities, in the modules
           database (see modules); this option bypasses it).

           Warning: this is not the same as the overall 'cvs -n' option, which
           you can specify to the left of a cvs command!

           Available with the checkout, commit, export, and rtag commands.

 -P
           Prune empty directories.  See Removing directories.

 -p
           Pipe the files retrieved from the repository to standard output,
           rather than writing them in the current directory.  Available with
           the checkout and update commands.

 -R
           Process directories recursively.  This is on by default.

           Available with the following commands: annotate, checkout, commit,
           diff, edit, editors, export, rdiff, remove, rtag, status, tag,
           unedit, update, watch, and watchers.

 -r tag
           Use the revision specified by the tag argument instead of the
           default head revision.  As well as arbitrary tags defined with the
           tag or rtag command, two special tags are always available: 'HEAD'
           refers to the most recent version available in the repository, and
           'BASE' refers to the revision you last checked out into the current
           working directory.

           The tag specification is sticky when you use this with checkout or
           update to make your own copy of a file: CVS remembers the tag and
           continues to use it on future update commands, until you specify
           otherwise (for more information on sticky tags/dates, see Sticky
           tags).  The tag can be either a symbolic or numeric tag. See Tags.

           Specifying the '-q' global option along with the '-r' command option
           is often useful, to suppress the warning messages when the RCS file
           does not contain the specified tag.

           Warning: this is not the same as the overall 'cvs -r' option, which
           you can specify to the left of a CVS command!

           '-r' is available with the checkout, commit, diff, history, export,
           rdiff, rtag, and update commands.

 -W
           Specify file names that should be filtered.  You can use this option
           repeatedly.  The spec can be a file name pattern of the same type
           that you can specify in the '.cvswrappers' file. Available with the
           following commands: import, and update.


ΓòÉΓòÉΓòÉ 17.6. admin---Administration ΓòÉΓòÉΓòÉ

     Requires: repository, working directory.

     Changes: repository.

     Synonym: rcs

 This is the CVS interface to assorted administrative facilities.  Some of them
 have questionable usefulness for CVS but exist for historical purposes.  Some
 of the questionable options are likely to disappear in the future.  This
 command does work recursively, so extreme care should be used.

 On unix, if there is a group named cvsadmin, only members of that group can
 run cvs admin. This group should exist on the server, or any system running
 the non-client/server CVS.  To disallow cvs admin for all users, create a
 group with no users in it.  On NT, the cvsadmin feature does not exist and all
 users can run cvs admin.

 admin options                 admin options


ΓòÉΓòÉΓòÉ 17.6.1. admin options ΓòÉΓòÉΓòÉ

 Some of these options have questionable usefulness for CVS but exist for
 historical purposes.  Some even make it impossible to use CVS until you undo
 the effect!

 -Aoldfile
           Might not work together with CVS.  Append the access list of oldfile
           to the access list of the RCS file.

 -alogins
           Might not work together with CVS.  Append the login names appearing
           in the comma-separated list logins to the access list of the RCS
           file.

 -b[rev]
           Set the default branch to rev.  In CVS, you normally do not
           manipulate default branches; sticky tags (see Sticky tags) are a
           better way to decide which branch you want to work on.  There is one
           reason to run cvs admin -b: to revert to the vendor's version when
           using vendor branches (see Reverting local changes). There can be no
           space between '-b' and its argument.

 -cstring
           Sets the comment leader to string.  The comment leader is not used
           by current versions of CVS or RCS 5.7.  Therefore, you can almost
           surely not worry about it.  See Keyword substitution.

 -e[logins]
           Might not work together with CVS.  Erase the login names appearing
           in the comma-separated list logins from the access list of the RCS
           file.  If logins is omitted, erase the entire access list.

 -I
           Run interactively, even if the standard input is not a terminal.
           This option does not work with the client/server CVS and is likely
           to disappear in a future release of CVS.

 -i
           Useless with CVS.  This creates and initializes a new RCS file,
           without depositing a revision.  With CVS, add files with the cvs add
           command (see Adding files).

 -ksubst
           Set the default keyword substitution to subst.  See Keyword
           substitution.  Giving an explicit '-k' option to cvs update, cvs
           export, or cvs checkout overrides this default.

 -l[rev]
           Lock the revision with number rev.  If a branch is given, lock the
           latest revision on that branch.  If rev is omitted, lock the latest
           revision on the default branch.  There can be no space between '-l'
           and its argument.

           This can be used in conjunction with the 'rcslock.pl' script in the
           'contrib' directory of the CVS source distribution to provide
           reserved checkouts (where only one user can be editing a given file
           at a time).  See the comments in that file for details (and see the
           'README' file in that directory for disclaimers about the
           unsupported nature of contrib).  According to comments in that file,
           locking must set to strict (which is the default).

 -L
           Set locking to strict.  Strict locking means that the owner of an
           RCS file is not exempt from locking for checkin.  For use with CVS,
           strict locking must be set; see the discussion under the '-l' option
           above.

 -mrev:msg
           Replace the log message of revision rev with msg.

 -Nname[:[rev]]
           Act like '-n', except override any previous assignment of name.  For
           use with magic branches, see Magic branch numbers.

 -nname[:[rev]]
           Associate the symbolic name name with the branch or revision rev.
           It is normally better to use 'cvs tag' or 'cvs rtag' instead.
           Delete the symbolic name if both ':' and rev are omitted; otherwise,
           print an error message if name is already associated with another
           number. If rev is symbolic, it is expanded before association.  A
           rev consisting of a branch number followed by a '.' stands for the
           current latest revision in the branch.  A ':' with an empty rev
           stands for the current latest revision on the default branch,
           normally the trunk.  For example, 'cvs admin -nname:' associates
           name with the current latest revision of all the RCS files; this
           contrasts with 'cvs admin -nname:$' which associates name with the
           revision numbers extracted from keyword strings in the corresponding
           working files.

 -orange
           Deletes (outdates) the revisions given by range.

           Note that this command can be quite dangerous unless you know
           exactly what you are doing (for example see the warnings below about
           how the rev1:rev2 syntax is confusing).

           If you are short on disc this option might help you. But think twice
           before using it---there is no way short of restoring the latest
           backup to undo this command! If you delete different revisions than
           you planned, either due to carelessness or (heaven forbid) a CVS
           bug, there is no opportunity to correct the error before the
           revisions are deleted.  It probably would be a good idea to
           experiment on a copy of the repository first.

           Specify range in one of the following ways:

             rev1::rev2
                         Collapse all revisions between rev1 and rev2, so that
                         CVS only stores the differences associated with going
                         from rev1 to rev2, not intermediate steps.  For
                         example, after '-o 1.3::1.5' one can retrieve revision
                         1.3, revision 1.5, or the differences to get from 1.3
                         to 1.5, but not the revision 1.4, or the differences
                         between 1.3 and 1.4.  Other examples: '-o 1.3::1.4'
                         and '-o 1.3::1.3' have no effect, because there are no
                         intermediate revisions to remove.

             ::rev
                         Collapse revisions between the beginning of the branch
                         containing rev and rev itself.  The branchpoint and
                         rev are left intact.  For example, '-o ::1.3.2.6'
                         deletes revision 1.3.2.1, revision 1.3.2.5, and
                         everything in between, but leaves 1.3 and 1.3.2.6
                         intact.

             rev::
                         Collapse revisions between rev and the end of the
                         branch containing rev.  Revision rev is left intact
                         but the head revision is deleted.

             rev
                         Delete the revision rev.  For example, '-o 1.3' is
                         equivalent to '-o 1.2::1.4'.

             rev1:rev2
                         Delete the revisions from rev1 to rev2, inclusive, on
                         the same branch.  One will not be able to retrieve
                         rev1 or rev2 or any of the revisions in between.  For
                         example, the command 'cvs admin -oR_1_01:R_1_02 .' is
                         rarely useful. It means to delete revisions up to, and
                         including, the tag R_1_02.  But beware!  If there are
                         files that have not changed between R_1_02 and R_1_03
                         the file will have the same numerical revision number
                         assigned to the tags R_1_02 and R_1_03.  So not only
                         will it be impossible to retrieve R_1_02; R_1_03 will
                         also have to be restored from the tapes!  In most
                         cases you want to specify rev1::rev2 instead.

             :rev
                         Delete revisions from the beginning of the branch
                         containing rev up to and including rev.

             rev:
                         Delete revisions from revision rev, including rev
                         itself, to the end of the branch containing rev.

             None of the revisions to be deleted may have branches or locks.

             If any of the revisions to be deleted have symbolic names, and one
             specifies one of the '::' syntaxes, then CVS will give an error
             and not delete any revisions.  If you really want to delete both
             the symbolic names and the revisions, first delete the symbolic
             names with cvs tag -d, then run cvs admin -o.  If one specifies
             the non-'::' syntaxes, then CVS will delete the revisions but
             leave the symbolic names pointing to nonexistent revisions.  This
             behavior is preserved for compatibility with previous versions of
             CVS, but because it isn't very useful, in the future it may change
             to be like the '::' case.

             Due to the way CVS handles branches rev cannot be specified
             symbolically if it is a branch. See Magic branch numbers, for an
             explanation. Make sure that no-one has checked out a copy of the
             revision you outdate.  Strange things will happen if he starts to
             edit it and tries to check it back in.  For this reason, this
             option is not a good way to take back a bogus commit; commit a new
             revision undoing the bogus change instead (see Merging two
             revisions).

 -q
           Run quietly; do not print diagnostics.

 -sstate[:rev]
           Useful with CVS.  Set the state attribute of the revision rev to
           state.  If rev is a branch number, assume the latest revision on
           that branch.  If rev is omitted, assume the latest revision on the
           default branch.  Any identifier is acceptable for state.  A useful
           set of states is 'Exp' (for experimental), 'Stab' (for stable), and
           'Rel' (for released).  By default, the state of a new revision is
           set to 'Exp' when it is created.  The state is visible in the output
           from cvs log (see log), and in the '$'Log$} and '$'State$} keywords
           (see Keyword substitution).  Note that CVS uses the dead state for
           its own purposes; to take a file to or from the dead state use
           commands like cvs remove and cvs add, not cvs admin -s.

 -t[file]
           Useful with CVS.  Write descriptive text from the contents of the
           named file into the RCS file, deleting the existing text.  The file
           pathname may not begin with '-'.  The descriptive text can be seen
           in the output from 'cvs log' (see log). There can be no space
           between '-t' and its argument.

           If file is omitted, obtain the text from standard input, terminated
           by end-of-file or by a line containing '.' by itself. Prompt for the
           text if interaction is possible; see '-I'.  Reading from standard
           input does not work for client/server CVS and may change in a future
           release of CVS.

 -t-string
           Similar to '-tfile'. Write descriptive text from the string into the
           RCS file, deleting the existing text. There can be no space between
           '-t' and its argument.

 -U
           Set locking to non-strict.  Non-strict locking means that the owner
           of a file need not lock a revision for checkin.  For use with CVS,
           strict locking must be set; see the discussion under the '-l' option
           above.

 -u[rev]
           See the option '-l' above, for a discussion of using this option
           with CVS.  Unlock the revision with number rev.  If a branch is
           given, unlock the latest revision on that branch.  If rev is
           omitted, remove the latest lock held by the caller. Normally, only
           the locker of a revision may unlock it. Somebody else unlocking a
           revision breaks the lock. This causes a mail message to be sent to
           the original locker.  The message contains a commentary solicited
           from the breaker.  The commentary is terminated by end-of-file or by
           a line containing . by itself. There can be no space between '-u'
           and its argument.

 -Vn
           In previous versions of CVS, this option meant to write an RCS file
           which would be acceptable to RCS version n, but it is now obsolete
           and specifying it will produce an error.

 -xsuffixes
           In previous versions of CVS, this was documented as a way of
           specifying the names of the RCS files.  However, CVS has always
           required that the RCS files used by CVS end in ',v', so this option
           has never done anything useful.


ΓòÉΓòÉΓòÉ 17.7. checkout---Check out sources for editing ΓòÉΓòÉΓòÉ

     Synopsis: checkout [options] modules┬╖┬╖┬╖

     Requires: repository.

     Changes: working directory.

     Synonyms: co, get

 Create or update a working directory containing copies of the source files
 specified by modules.  You must execute checkout before using most of the
 other CVS commands, since most of them operate on your working directory.

 The modules are either symbolic names for some collection of source
 directories and files, or paths to directories or files in the repository.
 The symbolic names are defined in the 'modules' file. See modules. Depending
 on the modules you specify, checkout may recursively create directories and
 populate them with the appropriate source files.  You can then edit these
 source files at any time (regardless of whether other software developers are
 editing their own copies of the sources); update them to include new changes
 applied by others to the source repository; or commit your work as a permanent
 change to the source repository.

 Note that checkout is used to create directories.  The top-level directory
 created is always added to the directory where checkout is invoked, and
 usually has the same name as the specified module.  In the case of a module
 alias, the created sub-directory may have a different name, but you can be
 sure that it will be a sub-directory, and that checkout will show the relative
 path leading to each file as it is extracted into your private work area
 (unless you specify the '-Q' global option).

 The files created by checkout are created read-write, unless the '-r' option
 to CVS (see Global options) is specified, the CVSREAD environment variable is
 specified (see Environment variables), or a watch is in effect for that file
 (see Watches).

 Note that running checkout on a directory that was already built by a prior
 checkout is also permitted. This is similar to specifying the '-d' option to
 the update command in the sense that new directories that have been created in
 the repository will appear in your work area. However, checkout takes a module
 name whereas update takes a directory name.  Also to use checkout this way it
 must be run from the top level directory (where you originally ran checkout
 from), so before you run checkout to update an existing directory, don't
 forget to change your directory to the top level directory.

 For the output produced by the checkout command see update output.

 checkout options              checkout options
 checkout examples             checkout examples


ΓòÉΓòÉΓòÉ 17.7.1. checkout options ΓòÉΓòÉΓòÉ

 These standard options are supported by checkout (see Common options, for a
 complete description of them):

 -D date
           Use the most recent revision no later than date. This option is
           sticky, and implies '-P'.  See Sticky tags, for more information on
           sticky tags/dates.

 -f
           Only useful with the '-D date' or '-r tag' flags.  If no matching
           revision is found, retrieve the most recent revision (instead of
           ignoring the file).

 -k kflag
           Process keywords according to kflag.  See Keyword substitution. This
           option is sticky; future updates of this file in this working
           directory will use the same kflag.  The status command can be viewed
           to see the sticky options.  See Invoking CVS, for more information
           on the status command.

 -l
           Local; run only in current working directory.

 -n
           Do not run any checkout program (as specified with the '-o' option
           in the modules file; see modules).

 -P
           Prune empty directories.  See Moving directories.

 -p
           Pipe files to the standard output.

 -R
           Checkout directories recursively.  This option is on by default.

 -r tag
           Use revision tag.  This option is sticky, and implies '-P'. See
           Sticky tags, for more information on sticky tags/dates.

 In addition to those, you can use these special command options with checkout:

 -A
           Reset any sticky tags, dates, or '-k' options. See Sticky tags, for
           more information on sticky tags/dates.

 -c
           Copy the module file, sorted, to the standard output, instead of
           creating or modifying any files or directories in your working
           directory.

 -d dir
           Create a directory called dir for the working files, instead of
           using the module name.  In general, using this flag is equivalent to
           using 'mkdir dir; cd dir' followed by the checkout command without
           the '-d' flag.

           There is an important exception, however.  It is very convenient
           when checking out a single item to have the output appear in a
           directory that doesn't contain empty intermediate directories.  In
           this case only, CVS tries to ``shorten'' pathnames to avoid those
           empty directories.

           For example, given a module 'foo' that contains the file 'bar.c',
           the command 'cvs co -d dir foo' will create directory 'dir' and
           place 'bar.c' inside.  Similarly, given a module 'bar' which has
           subdirectory 'baz' wherein there is a file 'quux.c', the command
           'cvs -d dir co bar/baz' will create directory 'dir' and place
           'quux.c' inside.

           Using the '-N' flag will defeat this behavior. Given the same module
           definitions above, 'cvs co -N -d dir foo' will create directories
           'dir/foo' and place 'bar.c' inside, while 'cvs co -N -d dir bar/baz'
           will create directories 'dir/bar/baz' and place 'quux.c' inside.

 -j tag
           With two '-j' options, merge changes from the revision specified
           with the first '-j' option to the revision specified with the second
           'j' option, into the working directory.

           With one '-j' option, merge changes from the ancestor revision to
           the revision specified with the '-j' option, into the working
           directory.  The ancestor revision is the common ancestor of the
           revision which the working directory is based on, and the revision
           specified in the '-j' option.

           In addition, each -j option can contain an optional date
           specification which, when used with branches, can limit the chosen
           revision to one within a specific date.  An optional date is
           specified by adding a colon (:) to the tag:
           '-jSymbolic_Tag:Date_Specifier'.

           See Branching and merging.

 -N
           Only useful together with '-d dir'.  With this option, CVS will not
           ``shorten'' module paths in your working directory when you check
           out a single module.  See the '-d' flag for examples and a
           discussion.

 -s
           Like '-c', but include the status of all modules, and sort it by the
           status string.  See modules, for info about the '-s' option that is
           used inside the modules file to set the module status.


ΓòÉΓòÉΓòÉ 17.7.2. checkout examples ΓòÉΓòÉΓòÉ

 Get a copy of the module 'tc':

                      $ cvs checkout tc

 Get a copy of the module 'tc' as it looked one day ago:

                      $ cvs checkout -D yesterday tc


ΓòÉΓòÉΓòÉ 17.8. commit---Check files into the repository ΓòÉΓòÉΓòÉ

     Synopsis: commit [-lnRf] [-m 'log_message' | -F file] [-r revision]
      [files┬╖┬╖┬╖]

     Requires: working directory, repository.

     Changes: repository.

     Synonym: ci

 Use commit when you want to incorporate changes from your working source files
 into the source repository.

 If you don't specify particular files to commit, all of the files in your
 working current directory are examined.  commit is careful to change in the
 repository only those files that you have really changed.  By default (or if
 you explicitly specify the '-R' option), files in subdirectories are also
 examined and committed if they have changed; you can use the '-l' option to
 limit commit to the current directory only.

 commit verifies that the selected files are up to date with the current
 revisions in the source repository; it will notify you, and exit without
 committing, if any of the specified files must be made current first with
 update (see update). commit does not call the update command for you, but
 rather leaves that for you to do when the time is right.

 When all is well, an editor is invoked to allow you to enter a log message
 that will be written to one or more logging programs (see modules, and see
 loginfo) and placed in the RCS file inside the repository.  This log message
 can be retrieved with the log command; see log.  You can specify the log
 message on the command line with the '-m message' option, and thus avoid the
 editor invocation, or use the '-F file' option to specify that the argument
 file contains the log message.

 commit options                commit options
 commit examples               commit examples


ΓòÉΓòÉΓòÉ 17.8.1. commit options ΓòÉΓòÉΓòÉ

 These standard options are supported by commit (see Common options, for a
 complete description of them):

 -l
           Local; run only in current working directory.

 -n
           Do not run any module program.

 -R
           Commit directories recursively.  This is on by default.

 -r revision
           Commit to revision.  revision must be either a branch, or a revision
           on the main trunk that is higher than any existing revision number
           (see Assigning revisions).  You cannot commit to a specific revision
           on a branch.

 commit also supports these options:

 -F file
           Read the log message from file, instead of invoking an editor.

 -f
           Note that this is not the standard behavior of the '-f' option as
           defined in Common options.

           Force CVS to commit a new revision even if you haven't made any
           changes to the file.  If the current revision of file is 1.7, then
           the following two commands are equivalent:

                      $ cvs commit -f file
                      $ cvs commit -r 1.8 file

 The '-f' option disables recursion (i.e., it implies '-l').  To force CVS to
 commit a new revision for all files in all subdirectories, you must use '-f
 -R'.

 -m message
           Use message as the log message, instead of invoking an editor.


ΓòÉΓòÉΓòÉ 17.8.2. commit examples ΓòÉΓòÉΓòÉ


ΓòÉΓòÉΓòÉ 17.8.2.1. Committing to a branch ΓòÉΓòÉΓòÉ

 You can commit to a branch revision (one that has an even number of dots) with
 the '-r' option.  To create a branch revision, use the '-b' option of the rtag
 or tag commands (see tag or see rtag).  Then, either checkout or update can be
 used to base your sources on the newly created branch.  From that point on,
 all commit changes made within these working sources will be automatically
 added to a branch revision, thereby not disturbing main-line development in
 any way.  For example, if you had to create a patch to the 1.2 version of the
 product, even though the 2.0 version is already under development, you might
 do:

                      $ cvs rtag -b -r FCS1_2 FCS1_2_Patch product_module
                      $ cvs checkout -r FCS1_2_Patch product_module
                      $ cd product_module
                      [[ hack away ]]
                      $ cvs commit

 This works automatically since the '-r' option is sticky.


ΓòÉΓòÉΓòÉ 17.8.2.2. Creating the branch after editing ΓòÉΓòÉΓòÉ

 Say you have been working on some extremely experimental software, based on
 whatever revision you happened to checkout last week.  If others in your group
 would like to work on this software with you, but without disturbing main-line
 development, you could commit your change to a new branch.  Others can then
 checkout your experimental stuff and utilize the full benefit of CVS conflict
 resolution.  The scenario might look like:

                      [[ hacked sources are present ]]
                      $ cvs tag -b EXPR1
                      $ cvs update -r EXPR1
                      $ cvs commit

 The update command will make the '-r EXPR1' option sticky on all files.  Note
 that your changes to the files will never be removed by the update command.
 The commit will automatically commit to the correct branch, because the '-r'
 is sticky.  You could also do like this:

                      [[ hacked sources are present ]]
                      $ cvs tag -b EXPR1
                      $ cvs commit -r EXPR1

 but then, only those files that were changed by you will have the '-r EXPR1'
 sticky flag.  If you hack away, and commit without specifying the '-r EXPR1'
 flag, some files may accidentally end up on the main trunk.

 To work with you on the experimental change, others would simply do

                      $ cvs checkout -r EXPR1 whatever_module


ΓòÉΓòÉΓòÉ 17.9. diff---Show differences between revisions ΓòÉΓòÉΓòÉ

     Synopsis: diff [-lR] [format_options] [[-r rev1 | -D date1] [-r rev2 |
      -D date2]] [files┬╖┬╖┬╖]

     Requires: working directory, repository.

     Changes: nothing.

 The diff command is used to compare different revisions of files.  The default
 action is to compare your working files with the revisions they were based on,
 and report any differences that are found.

 If any file names are given, only those files are compared.  If any
 directories are given, all files under them will be compared.

 The exit status for diff is different than for other CVS commands; for details
 Exit status.

 diff options                  diff options
 diff examples                 diff examples


ΓòÉΓòÉΓòÉ 17.9.1. diff options ΓòÉΓòÉΓòÉ

 These standard options are supported by diff (see Common options, for a
 complete description of them):

 -D date
           Use the most recent revision no later than date. See '-r' for how
           this affects the comparison.

 -k kflag
           Process keywords according to kflag.  See Keyword substitution.

 -l
           Local; run only in current working directory.

 -R
           Examine directories recursively.  This option is on by default.

 -r tag
           Compare with revision tag.  Zero, one or two '-r' options can be
           present.  With no '-r' option, the working file will be compared
           with the revision it was based on.  With one '-r', that revision
           will be compared to your current working file. With two '-r' options
           those two revisions will be compared (and your working file will not
           affect the outcome in any way). One or both '-r' options can be
           replaced by a '-D date' option, described above.

 The following options specify the format of the output.  They have the same
 meaning as in GNU diff.

                      -0 -1 -2 -3 -4 -5 -6 -7 -8 -9
                      --binary
                      --brief
                      --changed-group-format=arg
                      -c
                       -C nlines
                       --context[=lines]
                      -e --ed
                      -t --expand-tabs
                      -f --forward-ed
                      --horizon-lines=arg
                      --ifdef=arg
                      -w --ignore-all-space
                      -B --ignore-blank-lines
                      -i --ignore-case
                      -I regexp
                        --ignore-matching-lines=regexp
                      -h
                      -b --ignore-space-change
                      -T --initial-tab
                      -L label
                       --label=label
                      --left-column
                      -d --minimal
                      -N --new-file
                      --new-line-format=arg
                      --old-line-format=arg
                      --paginate
                      -n --rcs
                      -s --report-identical-files
                      -p
                      --show-c-function
                      -y --side-by-side
                      -F regexp
                      --show-function-line=regexp
                      -H --speed-large-files
                      --suppress-common-lines
                      -a --text
                      --unchanged-group-format=arg
                      -u
                       -U nlines
                       --unified[=lines]
                      -V arg
                      -W columns
                       --width=columns


ΓòÉΓòÉΓòÉ 17.9.2. diff examples ΓòÉΓòÉΓòÉ

 The following line produces a Unidiff ('-u' flag) between revision 1.14 and
 1.19 of 'backend.c'.  Due to the '-kk' flag no keywords are substituted, so
 differences that only depend on keyword substitution are ignored.

                      $ cvs diff -kk -u -r 1.14 -r 1.19 backend.c

 Suppose the experimental branch EXPR1 was based on a set of files tagged
 RELEASE_1_0.  To see what has happened on that branch, the following can be
 used:

                      $ cvs diff -r RELEASE_1_0 -r EXPR1

 A command like this can be used to produce a context diff between two
 releases:

                      $ cvs diff -c -r RELEASE_1_0 -r RELEASE_1_1 > diffs

 If you are maintaining ChangeLogs, a command like the following just before
 you commit your changes may help you write the ChangeLog entry.  All local
 modifications that have not yet been committed will be printed.

                      $ cvs diff -u | less


ΓòÉΓòÉΓòÉ 17.10. export---Export sources from CVS, similar to checkout ΓòÉΓòÉΓòÉ

     Synopsis: export [-flNnR] [-r rev|-D date] [-k subst] [-d dir] module┬╖┬╖┬╖

     Requires: repository.

     Changes: current directory.

 This command is a variant of checkout; use it when you want a copy of the
 source for module without the CVS administrative directories.  For example,
 you might use export to prepare source for shipment off-site.  This command
 requires that you specify a date or tag (with '-D' or '-r'), so that you can
 count on reproducing the source you ship to others.

 One often would like to use '-kv' with cvs export.  This causes any keywords
 to be expanded such that an import done at some other site will not lose the
 keyword revision information.  But be aware that doesn't handle an export
 containing binary files correctly.  Also be aware that after having used
 '-kv', one can no longer use the ident command (which is part of the RCS
 suite---see ident(1)) which looks for keyword strings.  If you want to be able
 to use ident you must not use '-kv'.

 export options                export options


ΓòÉΓòÉΓòÉ 17.10.1. export options ΓòÉΓòÉΓòÉ

 These standard options are supported by export (see Common options, for a
 complete description of them):

 -D date
           Use the most recent revision no later than date.

 -f
           If no matching revision is found, retrieve the most recent revision
           (instead of ignoring the file).

 -l
           Local; run only in current working directory.

 -n
           Do not run any checkout program.

 -R
           Export directories recursively.  This is on by default.

 -r tag
           Use revision tag.

 In addition, these options (that are common to checkout and export) are also
 supported:

 -d dir
           Create a directory called dir for the working files, instead of
           using the module name. See checkout options, for complete details on
           how CVS handles this flag.

 -k subst
           Set keyword expansion mode (see Substitution modes).

 -N
           Only useful together with '-d dir'. See checkout options, for
           complete details on how CVS handles this flag.


ΓòÉΓòÉΓòÉ 17.11. history---Show status of files and users ΓòÉΓòÉΓòÉ

     Synopsis:   history [-report] [-flags] [-options args] [files┬╖┬╖┬╖]

     Requires: the file '$CVSROOT/CVSROOT/history'

     Changes: nothing.

 CVS can keep a history file that tracks each use of the checkout, commit,
 rtag, update, and release commands.  You can use history to display this
 information in various formats.

 Logging must be enabled by creating the file '$CVSROOT/CVSROOT/history'.

 Warning: history uses '-f', '-l', '-n', and '-p' in ways that conflict with
 the normal use inside CVS (see Common options).

 history options               history options


ΓòÉΓòÉΓòÉ 17.11.1. history options ΓòÉΓòÉΓòÉ

 Several options (shown above as '-report')  control  what kind of report is
 generated:

 -c
           Report on each time commit was used (i.e., each time the repository
           was modified).

 -e
           Everything (all record types).  Equivalent to specifying '-x' with
           all record types.  Of course, '-e' will also include record types
           which are added in a future version of CVS; if you are writing a
           script which can only handle certain record types, you'll want to
           specify '-x'.

 -m module
           Report on a particular module.  (You can meaningfully use '-m' more
           than once on the command line.)

 -o
           Report on checked-out modules.

 -T
           Report on all tags.

 -x type
           Extract a particular set of record types type from the CVS history.
           The types are indicated by single letters, which you may specify in
           combination.

           Certain commands have a single record type:

             F
                         release

             O
                         checkout

             E
                         export

             T
                         rtag


             One of four record types may result from an update:

             C
                         A merge was necessary but collisions were detected
                         (requiring manual merging).

             G
                         A merge was necessary and it succeeded.

             U
                         A working file was copied from the repository.

             W
                         The working copy of a file was deleted during update
                         (because it was gone from the repository).


             One of three record types results from commit:

             A
                         A file was added for the first time.

             M
                         A file was modified.

             R
                         A file was removed.


 The options shown as '-flags' constrain or expand the report without requiring
 option arguments:

 -a
           Show data for all users (the default is to show data only for the
           user executing history).

 -l
           Show last modification only.

 -w
           Show only the records for modifications done from the same working
           directory where history is executing.

 The options shown as '-options args' constrain the report based on an
 argument:

 -b str
           Show data back to a record containing  the  string str  in  either
           the module name, the file name, or the repository path.

 -D date
           Show data since date.  This is slightly different from the normal
           use of '-D date', which selects the newest revision older than date.

 -p repository
           Show data for a particular source repository  (you can specify
           several '-p' options on the same command line).

 -r rev
           Show records referring to revisions since the revision or tag named
           rev appears in individual RCS files.  Each RCS file is searched for
           the revision or tag.

 -t tag
           Show records since tag tag was last added to the history file.  This
           differs from the '-r' flag above in that it reads only the history
           file, not the RCS files, and is much faster.

 -u name
           Show records for user name.


ΓòÉΓòÉΓòÉ 17.12. import---Import sources into CVS, using vendor branches ΓòÉΓòÉΓòÉ

     Synopsis: import [-options] repository vendortag releasetag┬╖┬╖┬╖

     Requires: Repository, source distribution directory.

     Changes: repository.

 Use import to incorporate an entire source distribution from an outside source
 (e.g., a source vendor) into your source repository directory.  You can use
 this command both for initial creation of a repository, and for wholesale
 updates to the module from the outside source.  See Tracking sources, for a
 discussion on this subject.

 The repository argument gives a directory name (or a path to a directory)
 under the CVS root directory for repositories; if the directory did not exist,
 import creates it.

 When you use import for updates to source that has been modified in your
 source repository (since a prior import), it will notify you of any files that
 conflict in the two branches of development; use 'checkout -j' to reconcile
 the differences, as import instructs you to do.

 If CVS decides a file should be ignored (see cvsignore), it does not import it
 and prints 'I ' followed by the filename (see import output, for a complete
 description of the output).

 If the file '$CVSROOT/CVSROOT/cvswrappers' exists, any file whose names match
 the specifications in that file will be treated as packages and the
 appropriate filtering will be performed on the file/directory before being
 imported.  See Wrappers.

 The outside source is saved in a first-level branch, by default 1.1.1.
 Updates are leaves of this branch; for example, files from the first imported
 collection of source will be revision 1.1.1.1, then files from the first
 imported update will be revision 1.1.1.2, and so on.

 At least three arguments are required. repository is needed to identify the
 collection of source.  vendortag is a tag for the entire branch (e.g., for
 1.1.1).  You must also specify at least one releasetag to identify the files
 at the leaves created each time you execute import.

 Note that import does not change the directory in which you invoke it.  In
 particular, it does not set up that directory as a CVS working directory; if
 you want to work with the sources import them first and then check them out
 into a different directory (see Getting the source).

 import options                import options
 import output                 import output
 import examples               import examples


ΓòÉΓòÉΓòÉ 17.12.1. import options ΓòÉΓòÉΓòÉ

 This standard option is supported by import (see Common options, for a
 complete description):

 -m message
           Use message as log information, instead of invoking an editor.

 There are the following additional special options.

 -b branch
           See Multiple vendor branches.

 -k subst
           Indicate the keyword expansion mode desired.  This setting will
           apply to all files created during the import, but not to any files
           that previously existed in the repository.  See Substitution modes,
           for a list of valid '-k' settings.

 -I name
           Specify file names that should be ignored during import.  You can
           use this option repeatedly.  To avoid ignoring any files at all
           (even those ignored by default), specify `-I !'.

           name can be a file name pattern of the same type that you can
           specify in the '.cvsignore' file. See cvsignore.

 -W spec
           Specify file names that should be filtered during import.  You can
           use this option repeatedly.

           spec can be a file name pattern of the same type that you can
           specify in the '.cvswrappers' file. See Wrappers.


ΓòÉΓòÉΓòÉ 17.12.2. import output ΓòÉΓòÉΓòÉ

 import keeps you informed of its progress by printing a line for each file,
 preceded by one character indicating the status of the file:

 U file
           The file already exists in the repository and has not been locally
           modified; a new revision has been created (if necessary).

 N file
           The file is a new file which has been added to the repository.

 C file
           The file already exists in the repository but has been locally
           modified; you will have to merge the changes.

 I file
           The file is being ignored (see cvsignore).

 L file
           The file is a symbolic link; cvs import ignores symbolic links.
           People periodically suggest that this behavior should be changed,
           but if there is a consensus on what it should be changed to, it
           doesn't seem to be apparent. (Various options in the 'modules' file
           can be used to recreate symbolic links on checkout, update, etc.;
           see modules.)


ΓòÉΓòÉΓòÉ 17.12.3. import examples ΓòÉΓòÉΓòÉ

 See Tracking sources, and From files.


ΓòÉΓòÉΓòÉ 17.13. log---Print out log information for files ΓòÉΓòÉΓòÉ

     Synopsis: log [options] [files┬╖┬╖┬╖]

     Requires: repository, working directory.

     Changes: nothing.

 Display log information for files.  log used to call the RCS utility rlog.
 Although this is no longer true in the current sources, this history
 determines the format of the output and the options, which are not quite in
 the style of the other CVS commands.

 The output includes the location of the RCS file, the head revision (the
 latest revision on the trunk), all symbolic names (tags) and some other
 things.  For each revision, the revision number, the author, the number of
 lines added/deleted and the log message are printed.  All times are displayed
 in Coordinated Universal Time (UTC).  (Other parts of CVS print times in the
 local timezone). Warning: log uses '-R' in a way that conflicts with the
 normal use inside CVS (see Common options).

 log options                   log options
 log examples                  log examples


ΓòÉΓòÉΓòÉ 17.13.1. log options ΓòÉΓòÉΓòÉ

 By default, log prints all information that is available.  All other options
 restrict the output.

 -b
           Print information about the revisions on the default branch,
           normally the highest branch on the trunk.

 -d dates
           Print information about revisions with a checkin date/time in the
           range given by the semicolon-separated list of dates.  The date
           formats accepted are those accepted by the '-D' option to many other
           CVS commands (see Common options). Dates can be combined into ranges
           as follows:

             d1<d2

             d2>d1
                         Select the revisions that were deposited between d1
                         and d2.

             <d

             d>
                         Select all revisions dated d or earlier.

             d<

             >d
                         Select all revisions dated d or later.

             d
                         Select the single, latest revision dated d or earlier.

             The '>' or '<' characters may be followed by '=' to indicate an
             inclusive range rather than an exclusive one.

             Note that the separator is a semicolon (;).

 -h
           Print only the name of the RCS file, name of the file in the working
           directory, head, default branch, access list, locks, symbolic names,
           and suffix.

 -l
           Local; run only in current working directory.  (Default is to run
           recursively).

 -N
           Do not print the list of tags for this file.  This option can be
           very useful when your site uses a lot of tags, so rather than
           "more"'ing over 3 pages of tag information, the log information is
           presented without tags at all.

 -R
           Print only the name of the RCS file.

 -rrevisions
           Print information about revisions given in the comma-separated list
           revisions of revisions and ranges.  The following table explains the
           available range formats:

             rev1:rev2
                         Revisions rev1 to rev2 (which must be on the same
                         branch).

             :rev
                         Revisions from the beginning of the branch up to and
                         including rev.

             rev:
                         Revisions starting with rev to the end of the branch
                         containing rev.

             branch
                         An argument that is a branch means all revisions on
                         that branch.

             branch1:branch2
                         A range of branches means all revisions on the
                         branches in that range.

             branch.
                         The latest revision in branch.

             A bare '-r' with no revisions means the latest revision on the
             default branch, normally the trunk. There can be no space between
             the '-r' option and its argument.

 -s states
           Print information about revisions whose state attributes match one
           of the states given in the comma-separated list states.

 -t
           Print the same as '-h', plus the descriptive text.

 -wlogins
           Print information about revisions checked in by users with login
           names appearing in the comma-separated list logins.  If logins is
           omitted, the user's login is assumed.  There can be no space between
           the '-w' option and its argument.

 log prints the intersection of the revisions selected with the options '-d',
 '-s', and '-w', intersected with the union of the revisions selected by '-b'
 and '-r'.


ΓòÉΓòÉΓòÉ 17.13.2. log examples ΓòÉΓòÉΓòÉ

 Contributed examples are gratefully accepted.


ΓòÉΓòÉΓòÉ 17.14. rdiff---'patch' format diffs between releases ΓòÉΓòÉΓòÉ

     rdiff [-flags] [-V vn] [-r t|-D d [-r t2|-D d2]] modules┬╖┬╖┬╖

     Requires: repository.

     Changes: nothing.

     Synonym: patch

 Builds a Larry Wall format patch(1) file between two releases, that can be fed
 directly into the patch program to bring an old release up-to-date with the
 new release.  (This is one of the few CVS commands that operates directly from
 the repository, and doesn't require a prior checkout.) The diff output is sent
 to the standard output device.

 You can specify (using the standard '-r' and '-D' options) any combination of
 one or two revisions or dates.  If only one revision or date is specified, the
 patch file reflects differences between that revision or date and the current
 head revisions in the RCS file.

 Note that if the software release affected is contained in more than one
 directory, then it may be necessary to specify the '-p' option to the patch
 command when patching the old sources, so that patch is able to find the files
 that are located in other directories.

 rdiff options                 rdiff options
 rdiff examples                rdiff examples


ΓòÉΓòÉΓòÉ 17.14.1. rdiff options ΓòÉΓòÉΓòÉ

 These standard options are supported by rdiff (see Common options, for a
 complete description of them):

 -D date
           Use the most recent revision no later than date.

 -f
           If no matching revision is found, retrieve the most recent revision
           (instead of ignoring the file).

 -l
           Local; don't descend subdirectories.

 -R
           Examine directories recursively.  This option is on by default.

 -r tag
           Use revision tag.

 In addition to the above, these options are available:

 -c
           Use the context diff format.  This is the default format.

 -s
           Create a summary change report instead of a patch.  The summary
           includes information about files that were changed or added between
           the releases.  It is sent to the standard output device.  This is
           useful for finding out, for example, which files have changed
           between two dates or revisions.

 -t
           A diff of the top two revisions is sent to the standard output
           device.  This is most useful for seeing what the last change to a
           file was.

 -u
           Use the unidiff format for the context diffs. This option is not
           available if your diff does not support the unidiff format.
           Remember that old versions of the patch program can't handle the
           unidiff format, so if you plan to post this patch to the net you
           should probably not use '-u'.

 -V vn
           Expand keywords according to the rules current in RCS version vn
           (the expansion format changed with RCS version 5).  Note that this
           option is no longer accepted.  CVS will always expand keywords the
           way that RCS version 5 does.


ΓòÉΓòÉΓòÉ 17.14.2. rdiff examples ΓòÉΓòÉΓòÉ

 Suppose you receive mail from [e-mail] asking for an update from release
 1.2 to 1.4 of the tc compiler.  You have no such patches on hand, but with CVS
 that can easily be fixed with a command such as this:

                      $ cvs rdiff -c -r FOO1_2 -r FOO1_4 tc | \
                      $$ Mail -s 'The patches you asked for' [e-mail]

 Suppose you have made release 1.3, and forked a branch called 'R_1_3fix' for
 bugfixes.  'R_1_3_1' corresponds to release 1.3.1, which was made some time
 ago.  Now, you want to see how much development has been done on the branch.
 This command can be used:

                      $ cvs patch -s -r R_1_3_1 -r R_1_3fix module-name
                      cvs rdiff: Diffing module-name
                      File ChangeLog,v changed from revision 1.52.2.5 to 1.52.2.6
                      File foo.c,v changed from revision 1.52.2.3 to 1.52.2.4
                      File bar.h,v changed from revision 1.29.2.1 to 1.2


ΓòÉΓòÉΓòÉ 17.15. release---Indicate that a Module is no longer in use ΓòÉΓòÉΓòÉ

     release [-d] directories┬╖┬╖┬╖

     Requires: Working directory.

     Changes: Working directory, history log.

 This command is meant to safely cancel the effect of 'cvs checkout'.  Since
 CVS doesn't lock files, it isn't strictly necessary to use this command.  You
 can always simply delete your working directory, if you like; but you risk
 losing changes you may have forgotten, and you leave no trace in the CVS
 history file (see history file) that you've abandoned your checkout.

 Use 'cvs release' to avoid these problems.  This command checks that no
 uncommitted changes are present; that you are executing it from immediately
 above a CVS working directory; and that the repository recorded for your files
 is the same as the repository defined in the module database.

 If all these conditions are true, 'cvs release' leaves a record of its
 execution (attesting to your intentionally abandoning your checkout) in the
 CVS history log.

 release options               release options
 release output                release output
 release examples              release examples


ΓòÉΓòÉΓòÉ 17.15.1. release options ΓòÉΓòÉΓòÉ

 The release command supports one command option:

 -d
           Delete your working copy of the file if the release succeeds.  If
           this flag is not given your files will remain in your working
           directory.

           Warning:  The release command deletes all directories and files
           recursively.  This has the very serious side-effect that any
           directory that you have created inside your checked-out sources, and
           not added to the repository (using the add command; see Adding
           files) will be silently deleted---even if it is non-empty!


ΓòÉΓòÉΓòÉ 17.15.2. release output ΓòÉΓòÉΓòÉ

 Before release releases your sources it will print a one-line message for any
 file that is not up-to-date.

 Warning:  Any new directories that you have created, but not added to the CVS
 directory hierarchy with the add command (see Adding files) will be silently
 ignored (and deleted, if '-d' is specified), even if they contain files.

 U file

 P file
           There exists a newer revision of this file in the repository, and
           you have not modified your local copy of the file ('U' and 'P' mean
           the same thing).

 A file
           The file has been added to your private copy of the sources, but has
           not yet been committed to the repository.  If you delete your copy
           of the sources this file will be lost.

 R file
           The file has been removed from your private copy of the sources, but
           has not yet been removed from the repository, since you have not yet
           committed the removal.  See commit.

 M file
           The file is modified in your working directory.  There might also be
           a newer revision inside the repository.

 ? file
           file is in your working directory, but does not correspond to
           anything in the source repository, and is not in the list of files
           for CVS to ignore (see the description of the '-I' option, and see
           cvsignore).  If you remove your working sources, this file will be
           lost.


ΓòÉΓòÉΓòÉ 17.15.3. release examples ΓòÉΓòÉΓòÉ

 Release the module, and delete your local working copy of the files.

                      $ cd ┬╖┬╖     # You must stand immediately above the
                              # sources when you issue 'cvs release'.
                      $ cvs release -d tc
                      You have [0] altered files in this repository.
                      Are you sure you want to release (and delete) module `tc': y
                      $


ΓòÉΓòÉΓòÉ 17.16. rtag---Add a symbolic tag to a module ΓòÉΓòÉΓòÉ

     rtag [-falnR] [-b] [-d] [-r tag | -Ddate] symbolic_tag modules┬╖┬╖┬╖

     Requires: repository.

     Changes: repository.

     Synonym: rfreeze

 You can use this command to assign symbolic tags to particular, explicitly
 specified source revisions in the repository.  rtag works directly on the
 repository contents (and requires no prior checkout). Use tag instead (see
 tag), to base the selection of revisions on the contents of your working
 directory.

 If you attempt to use a tag name that already exists, CVS will complain and
 not overwrite that tag.  Use the '-F' option to force the new tag value.

 rtag options                  rtag options


ΓòÉΓòÉΓòÉ 17.16.1. rtag options ΓòÉΓòÉΓòÉ

 These standard options are supported by rtag (see Common options, for a
 complete description of them):

 -D date
           Tag the most recent revision no later than date.

 -f
           Only useful with the '-D date' or '-r tag' flags.  If no matching
           revision is found, use the most recent revision (instead of ignoring
           the file).

 -F
           Overwrite an existing tag of the same name on a different revision.

 -l
           Local; run only in current working directory.

 -n
           Do not run any tag program that was specified with the '-t' flag
           inside the 'modules' file. (see modules).

 -R
           Tag directories recursively.  This is on by default.

 -r tag
           Only tag those files that contain tag.  This can be used to rename a
           tag: tag only the files identified by the old tag, then delete the
           old tag, leaving the new tag on exactly the same files as the old
           tag.

 In addition to the above common options, these options are available:

 -a
           Use the '-a' option to have rtag look in the 'Attic' (see Attic) for
           removed files that contain the specified tag.  The tag is removed
           from these files, which makes it convenient to re-use a symbolic tag
           as development continues (and files get removed from the up-coming
           distribution).

 -b
           Make the tag a branch tag.  See Branching and merging.

 -d
           Delete the tag instead of creating it.

           In general, tags (often the symbolic names of software
           distributions) should not be removed, but the '-d' option is
           available as a means to remove completely obsolete symbolic names if
           necessary (as might be the case for an Alpha release, or if you
           mistagged a module).


ΓòÉΓòÉΓòÉ 17.17. tag---Add a symbolic tag to checked out versions of files ΓòÉΓòÉΓòÉ

     tag [-lR] [-b] [-c] [-d] symbolic_tag [files┬╖┬╖┬╖]

     Requires: working directory, repository.

     Changes: repository.

     Synonym: freeze

 Use this command to assign symbolic tags to the nearest repository versions to
 your working sources.  The tags are applied immediately to the repository, as
 with rtag, but the versions are supplied implicitly by the CVS records of your
 working files' history rather than applied explicitly.

 One use for tags is to record a snapshot of the current sources when the
 software freeze date of a project arrives.  As bugs are fixed after the freeze
 date, only those changed sources that are to be part of the release need be
 re-tagged.

 The symbolic tags are meant to permanently record which revisions of which
 files were used in creating a software distribution.  The checkout and update
 commands allow you to extract an exact copy of a tagged release at any time in
 the future, regardless of whether files have been changed, added, or removed
 since the release was tagged.

 This command can also be used to delete a symbolic tag, or to create a branch.
 See the options section below.

 If you attempt to use a tag name that already exists, CVS will complain and
 not overwrite that tag.  Use the '-F' option to force the new tag value.

 tag options                   tag options


ΓòÉΓòÉΓòÉ 17.17.1. tag options ΓòÉΓòÉΓòÉ

 These standard options are supported by tag (see Common options, for a
 complete description of them):

 -F
           Overwrite an existing tag of the same name on a different revision.

 -l
           Local; run only in current working directory.

 -R
           Tag directories recursively.  This is on by default.

 Two special options are available:

 -b
           Make the tag a branch tag (see Branching and merging), allowing
           concurrent, isolated development.  This is most useful for creating
           a patch to a previously released software distribution.

 -c
           Check that all files which are to be tagged are unmodified.  This
           can be used to make sure that you can reconstruct the current file
           contents.

 -d
           Delete a tag.

           If you use 'cvs tag -d symbolic_tag', the symbolic tag you specify
           is deleted instead of being added. Warning: Be very certain of your
           ground before you delete a tag; doing this permanently discards some
           historical information, which may later turn out to be valuable.


ΓòÉΓòÉΓòÉ 17.18. update---Bring work tree in sync with repository ΓòÉΓòÉΓòÉ

     update [-AdflPpR] [-d] [-r tag|-D date] files┬╖┬╖┬╖

     Requires: repository, working directory.

     Changes: working directory.

 After you've run checkout to create your private copy of source from the
 common repository, other developers will continue changing the central source.
 From time to time, when it is convenient in your development process, you can
 use the update command from within your working directory to reconcile your
 work with any revisions applied to the source repository since your last
 checkout or update.

 update options                update options
 update output                 update output


ΓòÉΓòÉΓòÉ 17.18.1. update options ΓòÉΓòÉΓòÉ

 These standard options are available with update (see Common options, for a
 complete description of them):

 -D date
           Use the most recent revision no later than date. This option is
           sticky, and implies '-P'. See Sticky tags, for more information on
           sticky tags/dates.

 -f
           Only useful with the '-D date' or '-r tag' flags.  If no matching
           revision is found, retrieve the most recent revision (instead of
           ignoring the file).

 -k kflag
           Process keywords according to kflag.  See Keyword substitution. This
           option is sticky; future updates of this file in this working
           directory will use the same kflag.  The status command can be viewed
           to see the sticky options.  See Invoking CVS, for more information
           on the status command.

 -l
           Local; run only in current working directory.  See Recursive
           behavior.

 -P
           Prune empty directories.  See Moving directories.

 -p
           Pipe files to the standard output.

 -R
           Update directories recursively (default).  See Recursive behavior.

 -r rev
           Retrieve revision/tag rev.  This option is sticky, and implies '-P'.
           See Sticky tags, for more information on sticky tags/dates.

 These special options are also available with update.

 -A
           Reset any sticky tags, dates, or '-k' options. See Sticky tags, for
           more information on sticky tags/dates.

 -d
           Create any directories that exist in the repository if they're
           missing from the working directory.  Normally, update acts only on
           directories and files that were already enrolled in your working
           directory.

           This is useful for updating directories that were created in the
           repository since the initial checkout; but it has an unfortunate
           side effect.  If you deliberately avoided certain directories in the
           repository when you created your working directory (either through
           use of a module name or by listing explicitly the files and
           directories you wanted on the command line), then updating with '-d'
           will create those directories, which may not be what you want.

 -I name
           Ignore files whose names match name (in your working directory)
           during the update.  You can specify '-I' more than once on the
           command line to specify several files to ignore.  Use '-I !' to
           avoid ignoring any files at all.  See cvsignore, for other ways to
           make CVS ignore some files.

 -Wspec
           Specify file names that should be filtered during update.  You can
           use this option repeatedly.

           spec can be a file name pattern of the same type that you can
           specify in the '.cvswrappers' file. See Wrappers.

 -jrevision
           With two '-j' options, merge changes from the revision specified
           with the first '-j' option to the revision specified with the second
           'j' option, into the working directory.

           With one '-j' option, merge changes from the ancestor revision to
           the revision specified with the '-j' option, into the working
           directory.  The ancestor revision is the common ancestor of the
           revision which the working directory is based on, and the revision
           specified in the '-j' option.

           In addition, each '-j' option can contain an optional date
           specification which, when used with branches, can limit the chosen
           revision to one within a specific date.  An optional date is
           specified by adding a colon (:) to the tag:
           '-jSymbolic_Tag:Date_Specifier'.

           See Branching and merging.


ΓòÉΓòÉΓòÉ 17.18.2. update output ΓòÉΓòÉΓòÉ

 update and checkout keep you informed of their progress by printing a line for
 each file, preceded by one character indicating the status of the file:

 U file
           The file was brought up to date with respect to the repository.
           This is done for any file that exists in the repository but not in
           your source, and for files that you haven't changed but are not the
           most recent versions available in the repository.

 P file
           Like 'U', but the CVS server sends a patch instead of an entire
           file.  These two things accomplish the same thing.

 A file
           The file has been added to your private copy of the sources, and
           will be added to the source repository when you run commit on the
           file.  This is a reminder to you that the file needs to be
           committed.

 R file
           The file has been removed from your private copy of the sources, and
           will be removed from the source repository when you run commit on
           the file.  This is a reminder to you that the file needs to be
           committed.

 M file
           The file is modified in  your  working  directory.

           'M' can indicate one of two states for a file you're working on:
           either there were no modifications to the same file in the
           repository, so that your file remains as you last saw it; or there
           were modifications in the repository as well as in your copy, but
           they were merged successfully, without conflict, in your working
           directory.

           CVS will print some messages if it merges your work, and a backup
           copy of your working file (as it looked before you ran update) will
           be made.  The exact name of that file is printed while update runs.

 C file
           A conflict was detected while trying to merge your changes to file
           with changes from the source repository.  file (the copy in your
           working directory) is now the result of attempting to merge the two
           revisions; an unmodified copy of your file is also in your working
           directory, with the name '.#file.revision' where revision is the
           revision that your modified file started from.  Resolve the conflict
           as described in Conflicts example. (Note that some systems
           automatically purge files that begin with '.#' if they have not been
           accessed for a few days.  If you intend to keep a copy of your
           original file, it is a very good idea to rename it.)  Under VMS, the
           file name starts with '__' rather than '.#'.

 ? file
           file is in your working directory, but does not correspond to
           anything in the source repository, and is not in the list of files
           for CVS to ignore (see the description of the '-I' option, and see
           cvsignore).


ΓòÉΓòÉΓòÉ 18. Quick reference to CVS commands ΓòÉΓòÉΓòÉ

 This appendix describes how to invoke CVS, with references to where each
 command or feature is described in detail.  For other references run the cvs
 --help command, or see Index.

 A CVS command looks like:

                      cvs [ global_options ] command [ command_options ] [ command_args ]

 Global options:

 --allow-root=rootdir
           Specify legal CVSROOT directory (server only) (not in CVS 1.9 and
           older).  See Password authentication server.

 -a
           Authenticate all communication (client only) (not in CVS 1.9 and
           older).  See Global options.

 -b
           Specify RCS location (CVS 1.9 and older).  See Global options.

 -d root
           Specify the CVSROOT.  See Repository.

 -e editor
           Edit messages with editor.  See Committing your changes.

 -f
           Do not read the '~/.cvsrc' file.  See Global options.

 -H

 --help
           Print a help message.  See Global options.

 -l
           Do not log in CVSROOT/history file.  See Global options.

 -n
           Do not change any files.  See Global options.

 -Q
           Be really quiet.  See Global options.

 -q
           Be somewhat quiet.  See Global options.

 -r
           Make new working files read-only.  See Global options.

 -s variable=value
           Set a user variable.  See Variables.

 -T tempdir
           Put temporary files in tempdir.  See Global options.

 -t
           Trace CVS execution.  See Global options.

 -v

 --version
           Display version and copyright information for CVS.

 -w
           Make new working files read-write.  See Global options.

 -x
           Encrypt all communication (client only).  See Global options.

 -z gzip-level
           Set the compression level (client only).

 Keyword expansion modes (see Substitution modes):

                      -kkv  ${}Id: file1,v 1.1 1993/12/09 03:21:13 joe Exp $
                      -kkvl ${}Id: file1,v 1.1 1993/12/09 03:21:13 joe Exp harry $
                      -kk  ${}Id$
                      -kv  file1,v 1.1 1993/12/09 03:21:13 joe Exp
                      -ko  no expansion
                      -kb  no expansion, file is binary

 Keywords (see Keyword list):

                      ${}Author: joe $
                      ${}Date: 1993/12/09 03:21:13 $
                      ${}Header: /home/files/file1,v 1.1 1993/12/09 03:21:13 joe Exp harry $
                      ${}Id: file1,v 1.1 1993/12/09 03:21:13 joe Exp harry $
                      ${}Locker: harry $
                      ${}Name: snapshot_1_14 $
                      ${}RCSfile: file1,v $
                      ${}Revision: 1.1 $
                      ${}Source: /home/files/file1,v $
                      ${}State: Exp $
                      ${}Log: file1,v $
                      Revision 1.1  1993/12/09 03:30:17  joe
                      Initial revision

 Commands, command options, and command arguments:

 add [options] [files┬╖┬╖┬╖]
           Add a new file/directory.  See Adding files.

             -k kflag
                         Set keyword expansion.

             -m msg
                         Set file description.

 admin [options] [files┬╖┬╖┬╖]
           Administration of history files in the repository.  See admin.

             -b[rev]
                         Set default branch.  See Reverting local changes.

             -cstring
                         Set comment leader.

             -ksubst
                         Set keyword substitution.  See Keyword substitution.

             -l[rev]
                         Lock revision rev, or latest revision.

             -mrev:msg
                         Replace the log message of revision rev with msg.

             -orange
                         Delete revisions from the repository.  See admin
                         options.

             -q
                         Run quietly; do not print diagnostics.

             -sstate[:rev]
                         Set the state.

             -t
                         Set file description from standard input.

             -tfile
                         Set file description from file.

             -t-string
                         Set file description to string.

             -u[rev]
                         Unlock revision rev, or latest revision.

 annotate [options] [files┬╖┬╖┬╖]
           Show last revision where each line was modified.  See annotate.

             -D date
                         Annotate the most recent revision no later than date.
                         See Common options.

             -f
                         Use head revision if tag/date not found.  See Common
                         options.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -R
                         Operate recursively (default).  See Recursive
                         behavior.

             -r tag
                         Annotate revision tag.  See Common options.

 checkout [options] modules┬╖┬╖┬╖
           Get a copy of the sources.  See checkout.

             -A
                         Reset any sticky tags/date/options.  See Sticky tags
                         and Keyword substitution.

             -c
                         Output the module database.  See checkout options.

             -D date
                         Check out revisions as of date (is sticky).  See
                         Common options.

             -d dir
                         Check out into dir.  See checkout options.

             -f
                         Use head revision if tag/date not found.  See Common
                         options.

             -j rev
                         Merge in changes.  See checkout options.

             -k kflag
                         Use kflag keyword expansion.  See Substitution modes.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -N
                         Don't ``shorten'' module paths if -d specified.  See
                         checkout options.

             -n
                         Do not run module program (if any).  See checkout
                         options.

             -P
                         Prune empty directories.  See Moving directories.

             -p
                         Check out files to standard output (avoids
                         stickiness).  See checkout options.

             -R
                         Operate recursively (default).  See Recursive
                         behavior.

             -r tag
                         Checkout revision tag (is sticky).  See Common
                         options.

             -s
                         Like -c, but include module status.  See checkout
                         options.

 commit [options] [files┬╖┬╖┬╖]
           Check changes into the repository.  See commit.

             -F file
                         Read log message from file.  See commit options.

             -f
                         Force the file to be committed; disables recursion.
                         See commit options.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -m msg
                         Use msg as log message.  See commit options.

             -n
                         Do not run module program (if any).  See commit
                         options.

             -R
                         Operate recursively (default).  See Recursive
                         behavior.

             -r rev
                         Commit to rev.  See commit options.

 diff [options] [files┬╖┬╖┬╖]
           Show differences between revisions.  See diff. In addition to the
           options shown below, accepts a wide variety of options to control
           output style, for example '-c' for context diffs.

             -D date1
                         Diff revision for date against working file.  See diff
                         options.

             -D date2
                         Diff rev1/date1 against date2.  See diff options.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -N
                         Include diffs for added and removed files.  See diff
                         options.

             -R
                         Operate recursively (default).  See Recursive
                         behavior.

             -r rev1
                         Diff revision for rev1 against working file.  See diff
                         options.

             -r rev2
                         Diff rev1/date1 against rev2.  See diff options.

 edit [options] [files┬╖┬╖┬╖]
           Get ready to edit a watched file.  See Editing files.

             -a actions
                         Specify actions for temporary watch, where actions is
                         edit, unedit, commit, all, or none.  See Editing
                         files.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -R
                         Operate recursively (default).  See Recursive
                         behavior.

 editors [options] [files┬╖┬╖┬╖]
           See who is editing a watched file.  See Watch information.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -R
                         Operate recursively (default).  See Recursive
                         behavior.

 export [options] modules┬╖┬╖┬╖
           Export files from CVS.  See export.

             -D date
                         Check out revisions as of date.  See Common options.

             -d dir
                         Check out into dir.  See export options.

             -f
                         Use head revision if tag/date not found.  See Common
                         options.

             -k kflag
                         Use kflag keyword expansion.  See Substitution modes.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -N
                         Don't ``shorten'' module paths if -d specified.  See
                         export options.

             -n
                         Do not run module program (if any).  See export
                         options.

             -P
                         Prune empty directories.  See Moving directories.

             -R
                         Operate recursively (default).  See Recursive
                         behavior.

             -r tag
                         Checkout revision tag (is sticky).  See Common
                         options.

 history [options] [files┬╖┬╖┬╖]
           Show repository access history.  See history.

             -a
                         All users (default is self).  See history options.

             -b str
                         Back to record with str in module/file/repos field.
                         See history options.

             -c
                         Report on committed (modified) files.  See history
                         options.

             -D date
                         Since date.  See history options.

             -e
                         Report on all record types.  See history options.

             -l
                         Last modified (committed or modified report).  See
                         history options.

             -m module
                         Report on module (repeatable).  See history options.

             -n module
                         In module.  See history options.

             -o
                         Report on checked out modules.  See history options.

             -r rev
                         Since revision rev.  See history options.

             -T
                         Produce report on all TAGs.  See history options.

             -t tag
                         Since tag record placed in history file (by anyone).
                         See history options.

             -u user
                         For user user (repeatable).  See history options.

             -w
                         Working directory must match.  See history options.

             -x types
                         Report on types, one or more of TOEFWUCGMAR.  See
                         history options.

             -z zone
                         Output for time zone zone.  See history options.

 import [options] repository vendor-tag release-tags┬╖┬╖┬╖
           Import files into CVS, using vendor branches.  See import.

             -b bra
                         Import to vendor branch bra.  See Multiple vendor
                         branches.

             -d
                         Use the file's modification time as the time of
                         import.  See import options.

             -k kflag
                         Set default keyword substitution mode.  See import
                         options.

             -m msg
                         Use msg for log message.  See import options.

             -I ign
                         More files to ignore (! to reset).  See import
                         options.

             -W spec
                         More wrappers.  See import options.

 init
           Create a CVS repository if it doesn't exist.  See Creating a
           repository.

 log [options] [files┬╖┬╖┬╖]
           Print out history information for files.  See log.

             -b
                         Only list revisions on the default branch.  See log
                         options.

             -d dates
                         Specify dates (d1<d2 for range, d for latest before).
                         See log options.

             -h
                         Only print header.  See log options.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -N
                         Do not list tags.  See log options.

             -R
                         Only print name of RCS file.  See log options.

             -rrevs
                         Only list revisions revs.  See log options.

             -s states
                         Only list revisions with specified states.  See log
                         options.

             -t
                         Only print header and descriptive text.  See log
                         options.

             -wlogins
                         Only list revisions checked in by specified logins.
                         See log options.

 login
           Prompt for password for authenticating server.  See Password
           authentication client.

 logout
           Remove stored password for authenticating server.  See Password
           authentication client.

 rdiff [options] modules┬╖┬╖┬╖
           Show differences between releases.  See rdiff.

             -c
                         Context diff output format (default).  See rdiff
                         options.

             -D date
                         Select revisions based on date.  See Common options.

             -f
                         Use head revision if tag/date not found.  See Common
                         options.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -R
                         Operate recursively (default).  See Recursive
                         behavior.

             -r rev
                         Select revisions based on rev.  See Common options.

             -s
                         Short patch - one liner per file.  See rdiff options.

             -t
                         Top two diffs - last change made to the file.  See
                         diff options.

             -u
                         Unidiff output format.  See rdiff options.

             -V vers
                         Use RCS Version vers for keyword expansion (obsolete).
                         See rdiff options.

 release [options] directory
           Indicate that a directory is no longer in use.  See release.

             -d
                         Delete the given directory.  See release options.

 remove [options] [files┬╖┬╖┬╖]
           Remove an entry from the repository.  See Removing files.

             -f
                         Delete the file before removing it.  See Removing
                         files.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -R
                         Operate recursively (default).  See Recursive
                         behavior.

 rtag [options] tag modules┬╖┬╖┬╖
           Add a symbolic tag to a module.  See rtag.

             -a
                         Clear tag from removed files that would not otherwise
                         be tagged.  See rtag options.

             -b
                         Create a branch named tag.  See rtag options.

             -D date
                         Tag revisions as of date.  See rtag options.

             -d
                         Delete the given tag.  See rtag options.

             -F
                         Move tag if it already exists.  See rtag options.

             -f
                         Force a head revision match if tag/date not found. See
                         rtag options.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -n
                         No execution of tag program.  See rtag options.

             -R
                         Operate recursively (default).  See Recursive
                         behavior.

             -r tag
                         Tag existing tag tag.  See rtag options.

 status [options] files┬╖┬╖┬╖
           Display status information in a working directory.  See File status.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -R
                         Operate recursively (default).  See Recursive
                         behavior.

             -v
                         Include tag information for file.  See Tags.

 tag [options] tag [files┬╖┬╖┬╖]
           Add a symbolic tag to checked out version of files. See tag.

             -b
                         Create a branch named tag.  See tag options.

             -D date
                         Tag revisions as of date.  See tag options.

             -d
                         Delete the given tag.  See tag options.

             -F
                         Move tag if it already exists.  See tag options.

             -f
                         Force a head revision match if tag/date not found. See
                         tag options.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -n
                         No execution of tag program.  See tag options.

             -R
                         Operate recursively (default).  See Recursive
                         behavior.

             -r tag
                         Tag existing tag tag.  See tag options.

 unedit [options] [files┬╖┬╖┬╖]
           Undo an edit command.  See Editing files.

             -a actions
                         Specify actions for temporary watch, where actions is
                         edit, unedit, commit, all, or none.  See Editing
                         files.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -R
                         Operate recursively (default).  See Recursive
                         behavior.

 update [options] [files┬╖┬╖┬╖]
           Bring work tree in sync with repository.  See update.

             -A
                         Reset any sticky tags/date/options.  See Sticky tags
                         and Keyword substitution.

             -D date
                         Check out revisions as of date (is sticky).  See
                         Common options.

             -d
                         Create directories.  See update options.

             -f
                         Use head revision if tag/date not found.  See Common
                         options.

             -I ign
                         More files to ignore (! to reset).  See import
                         options.

             -j rev
                         Merge in changes.  See update options.

             -k kflag
                         Use kflag keyword expansion.  See Substitution modes.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -P
                         Prune empty directories.  See Moving directories.

             -p
                         Check out files to standard output (avoids
                         stickiness).  See update options.

             -R
                         Operate recursively (default).  See Recursive
                         behavior.

             -r tag
                         Checkout revision tag (is sticky).  See Common
                         options.

             -W spec
                         More wrappers.  See import options.

 watch [on|off|add|remove] [options] [files┬╖┬╖┬╖]
           on/off: turn on/off read-only checkouts of files.  See Setting a
           watch.

           add/remove: add or remove notification on actions.  See Getting
           Notified.

             -a actions
                         Specify actions for temporary watch, where actions is
                         edit, unedit, commit, all, or none.  See Editing
                         files.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -R
                         Operate recursively (default).  See Recursive
                         behavior.

 watchers [options] [files┬╖┬╖┬╖]
           See who is watching a file.  See Watch information.

             -l
                         Local; run only in current working directory.  See
                         Recursive behavior.

             -R
                         Operate recursively (default).  See Recursive
                         behavior.


ΓòÉΓòÉΓòÉ 19. Reference manual for Administrative files ΓòÉΓòÉΓòÉ

 Inside the repository, in the directory '$CVSROOT/CVSROOT', there are a number
 of supportive files for CVS.  You can use CVS in a limited fashion without any
 of them, but if they are set up properly they can help make life easier.  For
 a discussion of how to edit them, see Intro administrative files.

 The most important of these files is the 'modules' file, which defines the
 modules inside the repository.

 modules                       Defining modules
 Wrappers                      Treat directories as files
 commit files                  The commit support files
 commitinfo                    Pre-commit checking
 verifymsg                     How are log messages evaluated?
 editinfo                      Specifying how log messages are created
                               (obsolete)
 loginfo                       Where should log messages be sent?
 rcsinfo                       Templates for the log messages
 cvsignore                     Ignoring files via cvsignore
 history file                  History information
 Variables                     Various variables are expanded
 config                        Miscellaneous CVS configuration


ΓòÉΓòÉΓòÉ 19.1. The modules file ΓòÉΓòÉΓòÉ

 The 'modules' file records your definitions of names for collections of source
 code.  CVS will use these definitions if you use CVS to update the modules
 file (use normal commands like add, commit, etc).

 The 'modules' file may contain blank lines and comments (lines beginning with
 '#') as well as module definitions.  Long lines can be continued on the next
 line by specifying a backslash ('\') as the last character on the line.

 There are three basic types of modules: alias modules, regular modules, and
 ampersand modules.  The difference between them is the way that they map files
 in the repository to files in the working directory.  In all of the following
 examples, the top-level repository contains a directory called 'first-dir',
 which contains two files, 'file1' and 'file2', and a directory 'sdir'.
 'first-dir/sdir' contains a file 'sfile'.

 Alias modules                 The simplest kind of module
 Regular modules               Regular modules
 Ampersand modules             Ampersand modules
 Excluding directories         Excluding directories from a module
 Module options                Regular and ampersand modules can take options


ΓòÉΓòÉΓòÉ 19.1.1. Alias modules ΓòÉΓòÉΓòÉ

 Alias modules are the simplest kind of module:

 mname -a aliases┬╖┬╖┬╖
           This represents the simplest way of defining a module mname.  The
           '-a' flags the definition as a simple alias: CVS will treat any use
           of mname (as a command argument) as if the list of names aliases had
           been specified instead. aliases may contain either other module
           names or paths.  When you use paths in aliases, checkout creates all
           intermediate directories in the working directory, just as if the
           path had been specified explicitly in the CVS arguments.

 For example, if the modules file contains:

                      amodule -a first-dir

 then the following two commands are equivalent:

                      $ cvs co amodule
                      $ cvs co first-dir

 and they each would provide output such as:

                      cvs checkout: Updating first-dir
                      U first-dir/file1
                      U first-dir/file2
                      cvs checkout: Updating first-dir/sdir
                      U first-dir/sdir/sfile


ΓòÉΓòÉΓòÉ 19.1.2. Regular modules ΓòÉΓòÉΓòÉ

 mname [ options ] dir [ files┬╖┬╖┬╖ ]
           In the simplest case, this form of module definition reduces to
           'mname dir'.  This defines all the files in directory dir as module
           mname. dir is a relative path (from $CVSROOT) to a directory of
           source in the source repository.  In this case, on checkout, a
           single directory called mname is created as a working directory; no
           intermediate directory levels are used by default, even if dir was a
           path involving several directory levels.

 For example, if a module is defined by:

                      regmodule first-dir

 then regmodule will contain the files from first-dir:

                      $ cvs co regmodule
                      cvs checkout: Updating regmodule
                      U regmodule/file1
                      U regmodule/file2
                      cvs checkout: Updating regmodule/sdir
                      U regmodule/sdir/sfile
                      $

 By explicitly specifying files in the module definition after dir, you can
 select particular files from directory dir.  Here is an example:

                      regfiles first-dir/sdir sfile

 With this definition, getting the regfiles module will create a single working
 directory 'regfiles' containing the file listed, which comes from a directory
 deeper in the CVS source repository:

                      $ cvs co regfiles
                      U regfiles/sfile
                      $


ΓòÉΓòÉΓòÉ 19.1.3. Ampersand modules ΓòÉΓòÉΓòÉ

 A module definition can refer to other modules by including '&module' in its
 definition.

                      mname [ options ] &module┬╖┬╖┬╖

 Then getting the module creates a subdirectory for each such module, in the
 directory containing the module.  For example, if modules contains

                      ampermod &first-dir

 then a checkout will create an ampermod directory which contains a directory
 called first-dir, which in turns contains all the directories and files which
 live there.  For example, the command

                      $ cvs co ampermod

 will create the following files:

                      ampermod/first-dir/file1
                      ampermod/first-dir/file2
                      ampermod/first-dir/sdir/sfile

 There is one quirk/bug: the messages that CVS prints omit the 'ampermod', and
 thus do not correctly display the location to which it is checking out the
 files:

                      $ cvs co ampermod
                      cvs checkout: Updating first-dir
                      U first-dir/file1
                      U first-dir/file2
                      cvs checkout: Updating first-dir/sdir
                      U first-dir/sdir/sfile
                      $

 Do not rely on this buggy behavior; it may get fixed in a future release of
 CVS.


ΓòÉΓòÉΓòÉ 19.1.4. Excluding directories ΓòÉΓòÉΓòÉ

 An alias module may exclude particular directories from other modules by using
 an exclamation mark ('!') before the name of each directory to be excluded.

 For example, if the modules file contains:

                      exmodule -a !first-dir/sdir first-dir

 then checking out the module 'exmodule' will check out everything in
 'first-dir' except any files in the subdirectory 'first-dir/sdir'.


ΓòÉΓòÉΓòÉ 19.1.5. Module options ΓòÉΓòÉΓòÉ

 Either regular modules or ampersand modules can contain options, which supply
 additional information concerning the module.

 -d name
           Name the working directory something other than the module name.

 -e prog
           Specify a program prog to run whenever files in a module are
           exported.  prog runs with a single argument, the module name.

 -i prog
           Specify a program prog to run whenever files in a module are
           committed.  prog runs with a single argument, the full pathname of
           the affected directory in a source repository.  The 'commitinfo',
           'loginfo', and 'verifymsg' files provide other ways to call a
           program on commit.

 -o prog
           Specify a program prog to run whenever files in a module are checked
           out.  prog runs with a single argument, the module name.

 -s status
           Assign a status to the module.  When the module file is printed with
           'cvs checkout -s' the modules are sorted according to primarily
           module status, and secondarily according to the module name.  This
           option has no other meaning.  You can use this option for several
           things besides status: for instance, list the person that is
           responsible for this module.

 -t prog
           Specify a program prog to run whenever files in a module are tagged
           with rtag.  prog runs with two arguments: the module name and the
           symbolic tag specified to rtag.  It is not run when tag is executed.
           Generally you will find that taginfo is a better solution (see
           user-defined logging).

 -u prog
           Specify a program prog to run whenever 'cvs update' is executed from
           the top-level directory of the checked-out module.  prog runs with a
           single argument, the full path to the source repository for this
           module.


ΓòÉΓòÉΓòÉ 19.2. The cvswrappers file ΓòÉΓòÉΓòÉ

 Wrappers allow you to set a hook which transforms files on their way in and
 out of CVS.

 The file 'cvswrappers' defines the script that will be run on a file when its
 name matches a regular expresion. There are two scripts that can be run on a
 file or directory. One script is executed on the file/directory before being
 checked into the repository (this is denoted with the -t flag) and the other
 when the file is checked out of the repository (this is denoted with the -f
 flag).  The '-t'/'-f' feature does not work with client/server CVS. The
 'cvswrappers' also has a '-m' option to specify the merge methodology that
 should be used when a non-binary file is updated.  MERGE means the usual CVS
 behavior: try to merge the files.  COPY means that cvs update will refuse to
 merge files, as it also does for files specified as binary with '-kb' (but if
 the file is specified as binary, there is no need to specify '-m 'COPY''). CVS
 will provide the user with the two versions of the files, and require the user
 using mechanisms outside CVS, to insert any necessary changes.  WARNING: do
 not use COPY with CVS 1.9 or earlier--such versions of CVS will copy one
 version of your file over the other, wiping out the previous contents. The
 '-m' wrapper option only affects behavior when merging is done on update; it
 does not affect how files are stored.  See Binary files, for more on binary
 files.

 The basic format of the file 'cvswrappers' is:

                      wildcard   [option value][option value]┬╖┬╖┬╖
                      where option is one of
                      -f      from cvs filter     value: path to filter
                      -t      to cvs filter      value: path to filter
                      -m      update methodology    value: MERGE or COPY
                      -k      keyword expansion    value: expansion mode
                      and value is a single-quote delimited value.

                      *.nib   -f 'unwrap %s' -t 'wrap %s %s' -m 'COPY'
                      *.c    -t 'indent %s %s'

 The above example of a 'cvswrappers' file states that all files/directories
 that end with a .nib should be filtered with the 'wrap' program before
 checking the file into the repository. The file should be filtered though the
 'unwrap' program when the file is checked out of the repository. The
 'cvswrappers' file also states that a COPY methodology should be used when
 updating the files in the repository (that is, no merging should be
 performed).

 The last example line says that all files that end with .c should be filtered
 with 'indent' before being checked into the repository. Unlike the previous
 example, no filtering of the .c file is done when it is checked out of the
 repository.
 The -t filter is called with two arguments, the first is the name of the
 file/directory to filter and the second is the pathname to where the resulting
 filtered file should be placed.
 The -f filter is called with one argument, which is the name of the file to
 filter from. The end result of this filter will be a file in the users
 directory that they can work on as they normally would.

 Note that the '-t'/'-f' features do not conveniently handle one portion of
 CVS's operation: determining when files are modified.  CVS will still want a
 file (or directory) to exist, and it will use its modification time to
 determine whether a file is modified.  If CVS erroneously thinks a file is
 unmodified (for example, a directory is unchanged but one of the files within
 it is changed), you can force it to check in the file anyway by specifying the
 '-f' option to cvs commit (see commit options). For another example, the
 following command imports a directory, treating files whose name ends in
 '.exe' as binary:

                      cvs import -I ! -W "*.exe -k 'b'" first-dir vendortag reltag


ΓòÉΓòÉΓòÉ 19.3. The commit support files ΓòÉΓòÉΓòÉ

 The '-i' flag in the 'modules' file can be used to run a certain program
 whenever files are committed (see modules).  The files described in this
 section provide other, more flexible, ways to run programs whenever something
 is committed.

 There are three kind of programs that can be run on commit.  They are
 specified in files in the repository, as described below.  The following table
 summarizes the file names and the purpose of the corresponding programs.

 commitinfo
           The program is responsible for checking that the commit is allowed.
           If it exits with a non-zero exit status the commit will be aborted.

 verifymsg
           The specified program is used to evaluate the log message, and
           possibly verify that it contains all required fields.  This is most
           useful in combination with the 'rcsinfo' file, which can hold a log
           message template (see rcsinfo).

 editinfo
           The specified program is used to edit the log message, and possibly
           verify that it contains all required fields.  This is most useful in
           combination with the 'rcsinfo' file, which can hold a log message
           template (see rcsinfo).  (obsolete)

 loginfo
           The specified program is called when the commit is complete.  It
           receives the log message and some additional information and can
           store the log message in a file, or mail it to appropriate persons,
           or maybe post it to a local newsgroup, or┬╖┬╖┬╖  Your imagination is
           the limit!

 syntax                        The common syntax


ΓòÉΓòÉΓòÉ 19.3.1. The common syntax ΓòÉΓòÉΓòÉ

 The administrative files such as 'commitinfo', 'loginfo', 'rcsinfo',
 'verifymsg', etc., all have a common format.  The purpose of the files are
 described later on.  The common syntax is described here.

 Each line contains the following:

     A regular expression.  This is a basic regular expression in the syntax
      used by GNU emacs.

     A whitespace separator---one or more spaces and/or tabs.

     A file name or command-line template.

 Blank lines are ignored.  Lines that start with the character '#' are treated
 as comments.  Long lines unfortunately can not be broken in two parts in any
 way.

 The first regular expression that matches the current directory name in the
 repository is used.  The rest of the line is used as a file name or
 command-line as appropriate.


ΓòÉΓòÉΓòÉ 19.4. Commitinfo ΓòÉΓòÉΓòÉ

 The 'commitinfo' file defines programs to execute whenever 'cvs commit' is
 about to execute.  These programs are used for pre-commit checking to verify
 that the modified, added and removed files are really ready to be committed.
 This could be used, for instance, to verify that the changed files conform to
 to your site's standards for coding practice.

 As mentioned earlier, each line in the 'commitinfo' file consists of a regular
 expression and a command-line template.  The template can include a program
 name and any number of arguments you wish to supply to it.  The full path to
 the current source repository is appended to the template, followed by the
 file names of any files involved in the commit (added, removed, and modified
 files).

 The first line with a regular expression matching the relative path to the
 module will be used.  If the command returns a non-zero exit status the commit
 will be aborted.

 If the repository name does not match any of the regular expressions in this
 file, the 'DEFAULT' line is used, if it is specified.

 All occurances of the name 'ALL' appearing as a regular expression are used in
 addition to the first matching regular expression or the name 'DEFAULT'.

 Note: when CVS is accessing a remote repository, 'commitinfo' will be run on
 the remote (i.e., server) side, not the client side (see Remote repositories).


ΓòÉΓòÉΓòÉ 19.5. Verifying log messages ΓòÉΓòÉΓòÉ

 Once you have entered a log message, you can evaluate that message to check
 for specific content, such as a bug ID.  Use the 'verifymsg' file to specify a
 program that is used to verify the log message. This program could be a simple
 script that checks that the entered message contains the required fields.

 The 'verifymsg' file is often most useful together with the 'rcsinfo' file,
 which can be used to specify a log message template.

 Each line in the 'verifymsg' file consists of a regular expression and a
 command-line template.  The template must include a program name, and can
 include any number of arguments.  The full path to the current log message
 template file is appended to the template.

 One thing that should be noted is that the 'ALL' keyword is not supported.  If
 more than one matching line is found, the first one is used.  This can be
 useful for specifying a default verification script in a module, and then
 overriding it in a subdirectory.

 If the repository name does not match any of the regular expressions in this
 file, the 'DEFAULT' line is used, if it is specified.

 If the verification script exits with a non-zero exit status, the commit is
 aborted.

 Note that the verification script cannot change the log message; it can merely
 accept it or reject it. The following is a little silly example of a
 'verifymsg' file, together with the corresponding 'rcsinfo' file, the log
 message template and an verification  script.  We begin with the log message
 template. We want to always record a bug-id number on the first line of the
 log message.  The rest of log message is free text.  The following template is
 found in the file '/usr/cvssupport/tc.template'.

                      BugId:

 The script '/usr/cvssupport/bugid.verify' is used to evaluate the log message.

                      #!/bin/sh
                      #
                      #    bugid.verify filename
                      #
                      #  Verify that the log message contains a valid bugid
                      #  on the first line.
                      #
                      if head -1 < $1 | grep '^BugId:[ ]*[0-9][0-9]*$' > /dev/null; then
                        exit 0
                      else
                        echo "No BugId found."
                        exit 1
                      fi

 The 'verifymsg' file contains this line:

                      ^tc   /usr/cvssupport/bugid.edit

 The 'rcsinfo' file contains this line:

                      ^tc   /usr/cvssupport/tc.template


ΓòÉΓòÉΓòÉ 19.6. Editinfo ΓòÉΓòÉΓòÉ

 NOTE: The 'editinfo' feature has been rendered obsolete.  To set a default
 editor for log messages use the EDITOR environment variable (see Environment
 variables) or the '-e' global option (see Global options).  See verifymsg, for
 information on the use of the 'verifymsg' feature for evaluating log messages.

 If you want to make sure that all log messages look the same way, you can use
 the 'editinfo' file to specify a program that is used to edit the log message.
 This program could be a custom-made editor that always enforces a certain
 style of the log message, or maybe a simple shell script that calls an editor,
 and checks that the entered message contains the required fields.

 If no matching line is found in the 'editinfo' file, the editor specified in
 the environment variable $CVSEDITOR is used instead.  If that variable is not
 set, then the environment variable $EDITOR is used instead.  If that variable
 is not set a default will be used.  See Committing your changes.

 The 'editinfo' file is often most useful together with the 'rcsinfo' file,
 which can be used to specify a log message template.

 Each line in the 'editinfo' file consists of a regular expression and a
 command-line template.  The template must include a program name, and can
 include any number of arguments.  The full path to the current log message
 template file is appended to the template.

 One thing that should be noted is that the 'ALL' keyword is not supported.  If
 more than one matching line is found, the first one is used.  This can be
 useful for specifying a default edit script in a module, and then overriding
 it in a subdirectory.

 If the repository name does not match any of the regular expressions in this
 file, the 'DEFAULT' line is used, if it is specified.

 If the edit script exits with a non-zero exit status, the commit is aborted.

 Note: when CVS is accessing a remote repository, or when the '-m' or '-F'
 options to cvs commit are used, 'editinfo' will not be consulted. There is no
 good workaround for this; use 'verifymsg' instead.

 editinfo example              Editinfo example


ΓòÉΓòÉΓòÉ 19.6.1. Editinfo example ΓòÉΓòÉΓòÉ

 The following is a little silly example of a 'editinfo' file, together with
 the corresponding 'rcsinfo' file, the log message template and an editor
 script.  We begin with the log message template. We want to always record a
 bug-id number on the first line of the log message.  The rest of log message
 is free text.  The following template is found in the file
 '/usr/cvssupport/tc.template'.

                      BugId:

 The script '/usr/cvssupport/bugid.edit' is used to edit the log message.

                      #!/bin/sh
                      #
                      #    bugid.edit filename
                      #
                      #  Call $EDITOR on FILENAME, and verify that the
                      #  resulting file contains a valid bugid on the first
                      #  line.
                      if [ "x$EDITOR" = "x" ]; then EDITOR=vi; fi
                      if [ "x$CVSEDITOR" = "x" ]; then CVSEDITOR=$EDITOR; fi
                      $CVSEDITOR $1
                      until head -1|grep '^BugId:[ ]*[0-9][0-9]*$' < $1
                      do  echo -n  "No BugId found.  Edit again? ([y]/n)"
                        read ans
                        case ${ans} in
                          n*) exit 1;;
                        esac
                        $CVSEDITOR $1
                      done

 The 'editinfo' file contains this line:

                      ^tc   /usr/cvssupport/bugid.edit

 The 'rcsinfo' file contains this line:

                      ^tc   /usr/cvssupport/tc.template


ΓòÉΓòÉΓòÉ 19.7. Loginfo ΓòÉΓòÉΓòÉ

 The 'loginfo' file is used to control where 'cvs commit' log information is
 sent.  The first entry on a line is a regular expression which is tested
 against the directory that the change is being made to, relative to the
 $CVSROOT.  If a match is found, then the remainder of the line is a filter
 program that should expect log information on its standard input.

 If the repository name does not match any of the regular expressions in this
 file, the 'DEFAULT' line is used, if it is specified.

 All occurances of the name 'ALL' appearing as a regular expression are used in
 addition to the first matching regular expression or 'DEFAULT'.

 The first matching regular expression is used.

 See commit files, for a description of the syntax of the 'loginfo' file.

 The user may specify a format string as part of the filter.  The string is
 composed of a '%' followed by a space, or followed by a single format
 character, or followed by a set of format characters surrounded by '{' and '}'
 as separators.  The format characters are:

 s
           file name

 V
           old version number (pre-checkin)

 v
           new version number (post-checkin)

 All other characters that appear in a format string expand to an empty field
 (commas separating fields are still provided).

 For example, some valid format strings are '%', '%s', '%{s}', and '%{sVv}'.

 The output will be a string of tokens separated by spaces.  For backwards
 compatibility, the first token will be the repository name.  The rest of the
 tokens will be comma-delimited lists of the information requested in the
 format string.  For example, if '/u/src/master' is the repository, '%{sVv}' is
 the format string, and three files (ChangeLog, Makefile, foo.c) were modified,
 the output might be:

                      /u/src/master ChangeLog,1.1,1.2 Makefile,1.3,1.4 foo.c,1.12,1.13

 As another example, '%{}' means that only the name of the repository will be
 generated.

 Note: when CVS is accessing a remote repository, 'loginfo' will be run on the
 remote (i.e., server) side, not the client side (see Remote repositories).

 loginfo example               Loginfo example
 Keeping a checked out copy    Updating a tree on every checkin


ΓòÉΓòÉΓòÉ 19.7.1. Loginfo example ΓòÉΓòÉΓòÉ

 The following 'loginfo' file, together with the tiny shell-script below,
 appends all log messages to the file '$CVSROOT/CVSROOT/commitlog', and any
 commits to the administrative files (inside the 'CVSROOT' directory) are also
 logged in '/usr/adm/cvsroot-log'. Commits to the 'prog1' directory are mailed
 to ceder.

                      ALL       /usr/local/bin/cvs-log $CVSROOT/CVSROOT/commitlog $USER
                      ^CVSROOT     /usr/local/bin/cvs-log /usr/adm/cvsroot-log
                      ^prog1      Mail -s %s ceder

 The shell-script '/usr/local/bin/cvs-log' looks like this:

                      #!/bin/sh
                      (echo "------------------------------------------------------";
                       echo -n $2"  ";
                       date;
                       echo;
                       cat) >> $1


ΓòÉΓòÉΓòÉ 19.7.2. Keeping a checked out copy ΓòÉΓòÉΓòÉ

 It is often useful to maintain a directory tree which contains files which
 correspond to the latest version in the repository.  For example, other
 developers might want to refer to the latest sources without having to check
 them out, or you might be maintaining a web site with CVS and want every
 checkin to cause the files used by the web server to be updated. The way to do
 this is by having loginfo invoke cvs update.  Doing so in the naive way will
 cause a problem with locks, so the cvs update must be run in the background.
 Here is an example for unix (this should all be on one line):

                      ^cyclic-pages        (date; cat; (sleep 2; cd /u/www/local-docs;
                       cvs -q update -d) &) >> $CVSROOT/CVSROOT/updatelog 2>&1

 This will cause checkins to repository directories starting with cyclic-pages
 to update the checked out tree in '/u/www/local-docs'.


ΓòÉΓòÉΓòÉ 19.8. Rcsinfo ΓòÉΓòÉΓòÉ

 The 'rcsinfo' file can be used to specify a form to edit when filling out the
 commit log.  The 'rcsinfo' file has a syntax similar to the 'verifymsg',
 'commitinfo' and 'loginfo' files.  See syntax.  Unlike the other files the
 second part is not a command-line template.  Instead, the part after the
 regular expression should be a full pathname to a file containing the log
 message template.

 If the repository name does not match any of the regular expressions in this
 file, the 'DEFAULT' line is used, if it is specified.

 All occurances of the name 'ALL' appearing as a regular expression are used in
 addition to the first matching regular expression or 'DEFAULT'.

 The log message template will be used as a default log message.  If you
 specify a log message with 'cvs commit -m message' or 'cvs commit -f file'
 that log message will override the template.

 See verifymsg, for an example 'rcsinfo' file.

 When CVS is accessing a remote repository, the contents of 'rcsinfo' at the
 time a directory is first checked out will specify a template which does not
 then change.  If you edit 'rcsinfo' or its templates, you may need to check
 out a new working directory.


ΓòÉΓòÉΓòÉ 19.9. Ignoring files via cvsignore ΓòÉΓòÉΓòÉ

 There are certain file names that frequently occur inside your working copy,
 but that you don't want to put under CVS control.  Examples are all the object
 files that you get while you compile your sources. Normally, when you run 'cvs
 update', it prints a line for each file it encounters that it doesn't know
 about (see update output).

 CVS has a list of files (or sh(1) file name patterns) that it should ignore
 while running update, import and release. This list is constructed in the
 following way.

     The list is initialized to include certain file name patterns: names
      associated with CVS administration, or with other common source control
      systems; common names for patch files, object files, archive files, and
      editor backup files; and other names that are usually artifacts of
      assorted utilities. Currently, the default list of ignored file name
      patterns is:

                        RCS   SCCS   CVS   CVS.adm
                        RCSLOG  cvslog.*
                        tags   TAGS
                        .make.state   .nse_depinfo
                        *~    #*    .#*   ,*    _$*   *$
                        *.old  *.bak  *.BAK  *.orig  *.rej  .del-*
                        *.a   *.olb  *.o   *.obj  *.so   *.exe
                        *.Z   *.elc  *.ln
                        core

     The per-repository list in '$CVSROOT/CVSROOT/cvsignore' is appended to
      the list, if that file exists.

     The per-user list in '.cvsignore' in your home directory is appended to
      the list, if it exists.

     Any entries in the environment variable $CVSIGNORE is appended to the
      list.

     Any '-I' options given to CVS is appended.

     As CVS traverses through your directories, the contents of any
      '.cvsignore' will be appended to the list. The patterns found in
      '.cvsignore' are only valid for the directory that contains them, not for
      any sub-directories.

 In any of the 5 places listed above, a single exclamation mark ('!') clears
 the ignore list. This can be used if you want to store any file which normally
 is ignored by CVS.

 Specifying '-I !' to cvs import will import everything, which is generally
 what you want to do if you are importing files from a pristine distribution or
 any other source which is known to not contain any extraneous files.  However,
 looking at the rules above you will see there is a fly in the ointment; if the
 distribution contains any '.cvsignore' files, then the patterns from those
 files will be processed even if '-I !' is specified.  The only workaround is
 to remove the '.cvsignore' files in order to do the import.  Because this is
 awkward, in the future '-I !' might be modified to override '.cvsignore' files
 in each directory.

 Note that the syntax of the ignore files consists of a series of lines, each
 of which contains a space separated list of filenames.  This offers no clean
 way to specify filenames which contain spaces, but you can use a workaround
 like 'foo?bar' to match a file named 'foo bar' (it also matches 'fooxbar' and
 the like).  Also note that there is currently no way to specify comments.


ΓòÉΓòÉΓòÉ 19.10. The history file ΓòÉΓòÉΓòÉ

 The file '$CVSROOT/CVSROOT/history' is used to log information for the history
 command (see history).  This file must be created to turn on logging.  This is
 done automatically if the cvs init command is used to set up the repository
 (see Creating a repository).

 The file format of the 'history' file is documented only in comments in the
 CVS source code, but generally programs should use the cvs history command to
 access it anyway, in case the format changes with future releases of CVS.


ΓòÉΓòÉΓòÉ 19.11. Expansions in administrative files ΓòÉΓòÉΓòÉ

 Sometimes in writing an administrative file, you might want the file to be
 able to know various things based on environment CVS is running in.  There are
 several mechanisms to do that.

 To find the home directory of the user running CVS (from the HOME environment
 variable), use '~' followed by '/' or the end of the line. Likewise for the
 home directory of user, use '~user'.  These variables are expanded on the
 server machine, and don't get any reasonable expansion if pserver (see
 Password authenticated) is in use; therefore user variables (see below) may be
 a better choice to customize behavior based on the user running CVS. One may
 want to know about various pieces of information internal to CVS.  A CVS
 internal variable has the syntax ${variable}, where variable starts with a
 letter and consists of alphanumberic characters and '_'.  If the character
 following variable is a non-alphanumeric character other than '_', the '{' and
 '}' can be omitted.  The CVS internal variables are:

 CVSROOT
           This is the value of the CVS root in use. See Repository, for a
           description of the various ways to specify this.

 RCSBIN
           In CVS 1.9.18 and older, this specified the directory where CVS was
           looking for RCS programs.  Because CVS no longer runs RCS programs,
           specifying this internal variable is now an error.

 CVSEDITOR

 VISUAL

 EDITOR
           These all expand to the same value, which is the editor that CVS is
           using.  See Global options, for how to specify this.

 USER
           Username of the user running CVS (on the CVS server machine).

 If you want to pass a value to the administrative files which the user who is
 running CVS can specify, use a user variable.  To expand a user variable, the
 administrative file contains ${=variable}.  To set a user variable, specify
 the global option '-s' to CVS, with argument variable=value.  It may be
 particularly useful to specify this option via '.cvsrc' (see ~/.cvsrc).

 For example, if you want the administrative file to refer to a test directory
 you might create a user variable TESTDIR.  Then if CVS is invoked as

                      cvs -s TESTDIR=/work/local/tests

 and the administrative file contains sh ${=TESTDIR}/runtests, then that string
 is expanded to sh /work/local/tests/runtests.

 All other strings containing '$' are reserved; there is no way to quote a '$'
 character so that '$' represents itself.


ΓòÉΓòÉΓòÉ 19.12. The CVSROOT/config configuration file ΓòÉΓòÉΓòÉ

 The administrative file 'config' contains various miscellaneous settings which
 affect the behavior of CVS.  The syntax is slightly different from the other
 administrative files.  Variables are not expanded.  Lines which start with '#'
 are considered comments. Other lines consist of a keyword, '=', and a value.
 Note that this syntax is very strict. Extraneous spaces or tabs are not
 permitted. Currently defined keywords are:

 RCSBIN=bindir
           For CVS 1.9.12 through 1.9.18, this setting told CVS to look for RCS
           programs in the bindir directory.  Current versions of CVS do not
           run RCS programs; for compatibility this setting is accepted, but it
           does nothing.

 SystemAuth=value
           If value is 'yes', then pserver should check for users in the
           system's user database if not found in 'CVSROOT/passwd'.  If it is
           'no', then all pserver users must exist in 'CVSROOT/passwd'. The
           default is 'yes'.  For more on pserver, see Password authenticated.

 PreservePermissions=value
           Enable support for saving special device files, symbolic links, file
           permissions and ownerships in the repository.  The default value is
           'no'. See Special Files for the full implications of using this
           keyword.

 TopLevelAdmin=value
           Modify the 'checkout' command to create a 'CVS' directory at the top
           level of the new working directory, in addition to 'CVS' directories
           created within checked-out directories. The default value is 'no'.

           This option is useful if you find yourself performing many commands
           at the top level of your working directory, rather than in one of
           the checked out subdirectories.  The 'CVS' directory created there
           will mean you don't have to specify 'CVSROOT' for each command.  It
           also provides a place for the 'CVS/Template' file (see Working
           directory storage).


ΓòÉΓòÉΓòÉ 20. All environment variables which affect CVS ΓòÉΓòÉΓòÉ

 This is a complete list of all environment variables that affect CVS.

 $CVSIGNORE
           A whitespace-separated list of file name patterns that CVS should
           ignore. See cvsignore.

 $CVSWRAPPERS
           A whitespace-separated list of file name patterns that CVS should
           treat as wrappers. See Wrappers.

 $CVSREAD
           If this is set, checkout and update will try hard to make the files
           in your working directory read-only.  When this is not set, the
           default behavior is to permit modification of your working files.

 $CVSUMASK
           Controls permissions of files in the repository.  See File
           permissions.

 $CVSROOT
           Should contain the full pathname to the root of the CVS source
           repository (where the RCS files are kept).  This information must be
           available to CVS for most commands to execute; if $CVSROOT is not
           set, or if you wish to override it for one invocation, you can
           supply it on the command line: 'cvs -d cvsroot cvs_command┬╖┬╖┬╖' Once
           you have checked out a working directory, CVS stores the appropriate
           root (in the file 'CVS/Root'), so normally you only need to worry
           about this when initially checking out a working directory.

 $EDITOR

 $CVSEDITOR
           Specifies the program to use for recording log messages during
           commit.  $CVSEDITOR overrides $EDITOR.  See Committing your changes.

 $PATH
           If $RCSBIN is not set, and no path is compiled into CVS, it will use
           $PATH to try to find all programs it uses.

 $HOME

 $HOMEPATH

 $HOMEDRIVE
           Used to locate the directory where the '.cvsrc' file, and other such
           files, are searched.  On Unix, CVS just checks for HOME.  On Windows
           NT, the system will set HOMEDRIVE, for example to 'd:' and HOMEPATH,
           for example to '\joe'.  On Windows 95, you'll probably need to set
           HOMEDRIVE and HOMEPATH yourself.

 $CVS_RSH
           Specifies the external program which CVS connects with, when :ext:
           access method is specified. see Connecting via rsh.

 $CVS_SERVER
           Used in client-server mode when accessing a remote repository using
           RSH.  It specifies the name of the program to start on the server
           side when accessing a remote repository using RSH.  The default
           value is cvs.  see Connecting via rsh

 $CVS_PASSFILE
           Used in client-server mode when accessing the cvs login server.
           Default value is '$HOME/.cvspass'. see Password authentication
           client

 $CVS_CLIENT_PORT
           Used in client-server mode when accessing the server via Kerberos.
           see Kerberos authenticated

 $CVS_RCMD_PORT
           Used in client-server mode.  If set, specifies the port number to be
           used when accessing the RCMD demon on the server side. (Currently
           not used for Unix clients).

 $CVS_CLIENT_LOG
           Used for debugging only in client-server mode.  If set, everything
           send to the server is logged into '$CVS_CLIENT_LOG.in' and
           everything send from the server is logged into
           '$CVS_CLIENT_LOG.out'.

 $CVS_SERVER_SLEEP
           Used only for debugging the server side in client-server mode.  If
           set, delays the start of the server child process the specified
           amount of seconds so that you can attach to it with a debugger.

 $CVS_IGNORE_REMOTE_ROOT
           (What is the purpose of this variable?)

 $COMSPEC
           Used under OS/2 only.  It specifies the name of the command
           interpreter and defaults to CMD.EXE.

 $TMPDIR

 $TMP

 $TEMP
           Directory in which temporary files are located. The CVS server uses
           TMPDIR.  See Global options, for a description of how to specify
           this. Some parts of CVS will always use '/tmp' (via the tmpnam
           function provided by the system).

           On Windows NT, TMP is used (via the _tempnam function provided by
           the system).

           The patch program which is used by the CVS client uses TMPDIR, and
           if it is not set, uses '/tmp' (at least with GNU patch 2.1).  Note
           that if your server and client are both running CVS 1.9.10 or later,
           CVS will not invoke an external patch program.


ΓòÉΓòÉΓòÉ 21. Compatibility between CVS Versions ΓòÉΓòÉΓòÉ

 The repository format is compatible going back to CVS 1.3.  But see Watches
 Compatibility, if you have copies of CVS 1.6 or older and you want to use the
 optional developer communication features. The working directory format is
 compatible going back to CVS 1.5.  It did change between CVS 1.3 and CVS 1.5.
 If you run CVS 1.5 or newer on a working directory checked out with CVS 1.3,
 CVS will convert it, but to go back to CVS 1.3 you need to check out a new
 working directory with CVS 1.3.

 The remote protocol is interoperable going back to CVS 1.5, but no further
 (1.5 was the first official release with the remote protocol, but some older
 versions might still be floating around).  In many cases you need to upgrade
 both the client and the server to take advantage of new features and bugfixes,
 however.


ΓòÉΓòÉΓòÉ 22. Troubleshooting ΓòÉΓòÉΓòÉ

 If you are having trouble with CVS, this appendix may help.  If there is a
 particular error message which you are seeing, then you can look up the
 message alphabetically.  If not, you can look through the section on other
 problems to see if your problem is mentioned there.

 Error messages                Partial list of CVS errors
 Connection                    Trouble making a connection to a CVS server
 Other problems                Problems not readily listed by error message


ΓòÉΓòÉΓòÉ 22.1. Partial list of error messages ΓòÉΓòÉΓòÉ

 Here is a partial list of error messages that you may see from CVS.  It is not
 a complete list---CVS is capable of printing many, many error messages, often
 with parts of them supplied by the operating system, but the intention is to
 list the common and/or potentially confusing error messages.

 The messages are alphabetical, but introductory text such as 'cvs update: ' is
 not considered in ordering them.

 In some cases the list includes messages printed by old versions of CVS
 (partly because users may not be sure which version of CVS they are using at
 any particular moment).

 cvs command: authorization failed: server host rejected access
           This is a generic response when trying to connect to a pserver
           server which chooses not to provide a specific reason for denying
           authorization.  Check that the username and password specified are
           correct and that the CVSROOT specified is allowed by --allow-root in
           inetd.conf.  See Password authenticated.

 file:line: Assertion 'text' failed
           The exact format of this message may vary depending on your system.
           It indicates a bug in CVS, which can be handled as described in
           BUGS.

 cvs command: conflict: removed file was modified by second party
           This message indicates that you removed a file, and someone else
           modified it.  To resolve the conflict, first run 'cvs add file'.  If
           desired, look at the other party's modification to decide whether
           you still want to remove it.  If you don't want to remove it, stop
           here.  If you do want to remove it, proceed with 'cvs remove file'
           and commit your removal.

 cannot change permissions on temporary directory

                      Operation not permitted
 This message has been happening in a non-reproducible, occasional way when we
 run the client/server testsuite, both on Red Hat Linux 3.0.3 and 4.1.  We
 haven't been able to figure out what causes it, nor is it known whether it is
 specific to linux (or even to this particular machine!).  If the problem does
 occur on other unices, 'Operation not permitted' would be likely to read 'Not
 owner' or whatever the system in question uses for the unix EPERM error.  If
 you have any information to add, please let us know as described in BUGS.  If
 you experience this error while using CVS, retrying the operation which
 produced it should work fine.

 cannot open CVS/Entries for reading: No such file or directory
           This generally indicates a CVS internal error, and can be handled as
           with other CVS bugs (see BUGS).  Usually there is a workaround---the
           exact nature of which would depend on the situation but which
           hopefully could be figured out.

 cvs [init aborted]: cannot open CVS/Root: No such file or directory
           This message is harmless.  Provided it is not accompanied by other
           errors, the operation has completed successfully.  This message
           should not occur with current versions of CVS, but it is documented
           here for the benefit of CVS 1.9 and older.

 cvs [checkout aborted]: cannot rename file file to CVS/,,file: Invalid
 argument
           This message has been reported as intermittently happening with CVS
           1.9 on Solaris 2.5.  The cause is unknown; if you know more about
           what causes it, let us know as described in BUGS.

 cvs [command aborted]: cannot start server via rcmd
           This, unfortunately, is a rather nonspecific error message which CVS
           1.9 will print if you are running the CVS client and it is having
           trouble connecting to the server.  Current versions of CVS should
           print a much more specific error message.  If you get this message
           when you didn't mean to run the client at all, you probably forgot
           to specify :local:, as described in Repository.

 ci: file,v: bad diff output line: Binary files - and /tmp/T2a22651 differ
           CVS 1.9 and older will print this message when trying to check in a
           binary file if RCS is not correctly installed.  Re-read the
           instructions that came with your RCS distribution and the INSTALL
           file in the CVS distribution.  Alternately, upgrade to a current
           version of CVS, which checks in files itself rather than via RCS.

 cvs checkout: could not check out file
           With CVS 1.9, this can mean that the co program (part of RCS)
           returned a failure.  It should be preceded by another error message,
           however it has been observed without another error message and the
           cause is not well-understood.  With the current version of CVS,
           which does not run co, if this message occurs without another error
           message, it is definitely a CVS bug (see BUGS).

 cvs [login aborted]: could not find out home directory
           This means that you need to set the environment variables that CVS
           uses to locate your home directory. See the discussion of HOME,
           HOMEDRIVE, and HOMEPATH in Environment variables.

 cvs update: could not merge revision rev of file: No such file or directory
           CVS 1.9 and older will print this message if there was a problem
           finding the rcsmerge program.  Make sure that it is in your PATH, or
           upgrade to a current version of CVS, which does not require an
           external rcsmerge program.

 cvs [update aborted]: could not patch file: No such file or directory
           This means that there was a problem finding the patch program.  Make
           sure that it is in your PATH.  Note that despite appearances the
           message is not referring to whether it can find file. If both the
           client and the server are running a current version of CVS, then
           there is no need for an external patch program and you should not
           see this message.  But if either client or server is running CVS
           1.9, then you need patch.

 cvs update: could not patch file; will refetch
           This means that for whatever reason the client was unable to apply a
           patch that the server sent.  The message is nothing to be concerned
           about, because inability to apply the patch only slows things down
           and has no effect on what CVS does.

 dying gasps from server unexpected
           There is a known bug in the server for CVS 1.9.18 and older which
           can cause this.  For me, this was reproducible if I used the '-t'
           global option.  It was fixed by Andy Piper's 14 Nov 1997 change to
           src/filesubr.c, if anyone is curious. If you see the message, you
           probably can just retry the operation which failed, or if you have
           discovered information concerning its cause, please let us know as
           described in BUGS.

 end of file from server (consult above messages if any)
           The most common cause for this message is if you are using an
           external rsh program and it exited with an error.  In this case the
           rsh program should have printed a message, which will appear before
           the above message.  For more information on setting up a CVS client
           and server, see Remote repositories.

 cvs commit: Executing 'mkmodules'
           This means that your repository is set up for a version of CVS prior
           to CVS 1.8.  When using CVS 1.8 or later, the above message will be
           preceded by

                      cvs commit: Rebuilding administrative file database

 If you see both messages, the database is being rebuilt twice, which is
 unnecessary but harmless.  If you wish to avoid the duplication, and you have
 no versions of CVS 1.7 or earlier in use, remove -i mkmodules every place it
 appears in your modules file.  For more information on the modules file, see
 modules.

 missing author
           Typically this can happen if you created an RCS file with your
           username set to empty.  CVS will, bogusly, create an illegal RCS
           file with no value for the author field.  The solution is to make
           sure your username is set to a non-empty value and re-create the RCS
           file.

 *PANIC* administration files missing
           This typically means that there is a directory named CVS but it does
           not contain the administrative files which CVS puts in a CVS
           directory.  If the problem is that you created a CVS directory via
           some mechanism other than CVS, then the answer is simple, use a name
           other than CVS.  If not, it indicates a CVS bug (see BUGS).

 rcs error: Unknown option: -x,v/
           This message will be followed by a usage message for RCS.  It means
           that you have an old version of RCS (probably supplied with your
           operating system).  CVS only works with RCS version 5 and later.

 cvs [server aborted]: received broken pipe signal
           This message seems to be caused by a hard-to-track-down bug in CVS
           or the systems it runs on (we don't know---we haven't tracked it
           down yet!).  It seems to happen only after a CVS command has
           completed, and you should be able to just ignore the message.
           However, if you have discovered information concerning its cause,
           please let us know as described in BUGS.

 Too many arguments!
           This message is typically printed by the 'log.pl' script which is in
           the 'contrib' directory in the CVS source distribution.  In some
           versions of CVS, 'log.pl' has been part of the default CVS
           installation.  The 'log.pl' script gets called from the 'loginfo'
           administrative file. Check that the arguments passed in 'loginfo'
           match what your version of 'log.pl' expects.  In particular, the
           'log.pl' from CVS 1.3 and older expects the logfile as an argument
           whereas the 'log.pl' from CVS 1.5 and newer expects the logfile to
           be specified with a '-f' option.  Of course, if you don't need
           'log.pl' you can just comment it out of 'loginfo'.

 cvs commit: Up-to-date check failed for `file'
           This means that someone else has committed a change to that file
           since the last time that you did a cvs update.  So before proceeding
           with your cvs commit you need to cvs update.  CVS will merge the
           changes that you made and the changes that the other person made.
           If it does not detect any conflicts it will report 'M cacErrCodes.h'
           and you are ready to cvs commit.  If it detects conflicts it will
           print a message saying so, will report 'C cacErrCodes.h', and you
           need to manually resolve the conflict.  For more details on this
           process see Conflicts example.

 Usage:    diff3 [-exEX3 [-i | -m] [-L label1 -L label3]] file1 file2 file3

                      Only one of [exEX3] allowed
 This indicates a problem with the installation of diff3 and rcsmerge.
 Specifically rcsmerge was compiled to look for GNU diff3, but it is finding
 unix diff3 instead.  The exact text of the message will vary depending on the
 system.  The simplest solution is to upgrade to a current version of CVS,
 which does not rely on external rcsmerge or diff3 programs.

 warning: unrecognized response `text' from cvs server
           If text contains a valid response (such as 'ok') followed by an
           extra carriage return character (on many systems this will cause the
           second part of the message to overwrite the first part), then it
           probably means that you are using the ':ext:' access method with a
           version of rsh, such as most non-unix rsh versions, which does not
           by default provide a transparent data stream.  In such cases you
           probably want to try ':server:' instead of ':ext:'.  If text is
           something else, this may signify a problem with your CVS server.
           Double-check your installation against the instructions for setting
           up the CVS server.

 cvs commit: warning: editor session failed
           This means that the editor which CVS is using exits with a nonzero
           exit status.  Some versions of vi will do this even when there was
           not a problem editing the file.  If so, point the CVSEDITOR
           environment variable to a small script such as:

                      #!/bin/sh
                      vi $*
                      exit 0


ΓòÉΓòÉΓòÉ 22.2. Trouble making a connection to a CVS server ΓòÉΓòÉΓòÉ

 This section concerns what to do if you are having trouble making a connection
 to a CVS server.  If you are running the CVS command line client running on
 Windows, first upgrade the client to CVS 1.9.12 or later.  The error reporting
 in earlier versions provided much less information about what the problem was.
 If the client is non-Windows, CVS 1.9 should be fine.

 If the error messages are not sufficient to track down the problem, the next
 steps depend largely on which access method you are using.

 :ext:
           Try running the rsh program from the command line.  For example:
           "rsh servername cvs -v" should print CVS version information.  If
           this doesn't work, you need to fix it before you can worry about CVS
           problems.

 :server:
           You don't need a command line rsh program to use this access method,
           but if you have an rsh program around, it may be useful as a
           debugging tool.  Follow the directions given for :ext:.

 :pserver:
           One good debugging tool is to "telnet servername 2401".  After
           connecting, send any text (for example "foo" followed by return).
           If CVS is working correctly, it will respond with

                      cvs [pserver aborted]: bad auth protocol start: foo

 If this fails to work, then make sure inetd is working right.  Change the
 invocation in inetd.conf to run the echo program instead of cvs.  For example:

                      2401  stream  tcp  nowait  root /bin/echo echo hello

 After making that change and instructing inetd to re-read its configuration
 file, "telnet servername 2401" should show you the text hello and then the
 server should close the connection.  If this doesn't work, you need to fix it
 before you can worry about CVS problems.

 On AIX systems, the system will often have its own program trying to use port
 2401.  This is AIX's problem in the sense that port 2401 is registered for use
 with CVS.  I hear that there is an AIX patch available to address this
 problem.


ΓòÉΓòÉΓòÉ 22.3. Other common problems ΓòÉΓòÉΓòÉ

 Here is a list of problems which do not fit into the above categories.  They
 are in no particular order.

     If you are running CVS 1.9.18 or older, and cvs update finds a conflict
      and tries to merge, as described in Conflicts example, but doesn't tell
      you there were conflicts, then you may have an old version of RCS.  The
      easiest solution probably is to upgrade to a current version of CVS,
      which does not rely on external RCS programs.


ΓòÉΓòÉΓòÉ 23. Credits ΓòÉΓòÉΓòÉ

 Roland Pesch, then of Cygnus Support <[e-mail]> wrote the manual pages
 which were distributed with CVS 1.3.  Much of their text was copied into this
 manual.  He also read an early draft of this manual and contributed many ideas
 and corrections.

 The mailing-list info-cvs is sometimes informative. I have included
 information from postings made by the following persons: David G. Grubbs
 <[e-mail]>.

 Some text has been extracted from the man pages for RCS.

 The CVS FAQ by David G. Grubbs has provided useful material.  The FAQ is no
 longer maintained, however, and this manual is about the closest thing there
 is to a successor (with respect to documenting how to use CVS, at least).

 In addition, the following persons have helped by telling me about mistakes
 I've made:

                      Roxanne Brunskill <[e-mail]>,
                      Kathy Dyer <[e-mail]>,
                      Karl Pingle <[e-mail]>,
                      Thomas A Peterson <[e-mail]>,
                      Inge Wallin <[e-mail]>,
                      Dirk Koschuetzki <[e-mail]>
                      and Michael Brown <[e-mail]>.

 The list of contributors here is not comprehensive; for a more complete list
 of who has contributed to this manual see the file 'doc/ChangeLog' in the CVS
 source distribution.


ΓòÉΓòÉΓòÉ 24. Dealing with bugs in CVS or this manual ΓòÉΓòÉΓòÉ

 Neither CVS nor this manual is perfect, and they probably never will be.  If
 you are having trouble using CVS, or think you have found a bug, there are a
 number of things you can do about it.  Note that if the manual is unclear,
 that can be considered a bug in the manual, so these problems are often worth
 doing something about as well as problems with CVS itself.

     If you want someone to help you and fix bugs that you report, there are
      companies which will do that for a fee.  Two such companies are:

                      Signum Support AB
                      Box 2044
                      S-580 02  Linkoping
                      Sweden
                      Email: [e-mail]
                      Phone: +46 (0)13 - 21 46 00
                      Fax:  +46 (0)13 - 21 47 00
                      http://www.signum.se/
                      Cyclic Software
                      United States of America
                      http://www.cyclic.com/
                      [e-mail]

     If you got CVS through a distributor, such as an operating system vendor
      or a vendor of freeware CD-ROMs, you may wish to see whether the
      distributor provides support.  Often, they will provide no support or
      minimal support, but this may vary from distributor to distributor.

     If you have the skills and time to do so, you may wish to fix the bug
      yourself.  If you wish to submit your fix for inclusion in future
      releases of CVS, see the file HACKING in the CVS source distribution.  It
      contains much more information on the process of submitting fixes.

     There may be resources on the net which can help.  Two good places to
      start are:

                      http://www.cyclic.com
                      http://www.loria.fr/~molli/cvs-index.html

 If you are so inspired, increasing the information available on the net is
 likely to be appreciated.  For example, before the standard CVS distribution
 worked on Windows 95, there was a web page with some explanation and patches
 for running CVS on Windows 95, and various people helped out by mentioning
 this page on mailing lists or newsgroups when the subject came up.

     It is also possible to report bugs to bug-cvs. Note that someone may or
      may not want to do anything with your bug report---if you need a solution
      consider one of the options mentioned above.  People probably do want to
      hear about bugs which are particularly severe in consequences and/or easy
      to fix, however.  You can also increase your odds by being as clear as
      possible about the exact nature of the bug and any other relevant
      information.  The way to report bugs is to send email to [e-mail].
      Note that submissions to bug-cvs may be distributed under the terms of
      the GNU Public License, so if you don't like this, don't submit them.
      There is usually no justification for sending mail directly to one of the
      CVS maintainers rather than to bug-cvs; those maintainers who want to
      hear about such bug reports read bug-cvs.  Also note that sending a bug
      report to other mailing lists or newsgroups is not a substitute for
      sending it to bug-cvs.  It is fine to discuss CVS bugs on whatever forum
      you prefer, but there are not necessarily any maintainers reading bug
      reports sent anywhere except bug-cvs.

 People often ask if there is a list of known bugs or whether a particular bug
 is a known one.  The file BUGS in the CVS source distribution is one list of
 known bugs, but it doesn't necessarily try to be comprehensive.  Perhaps there
 will never be a comprehensive, detailed list of known bugs.


ΓòÉΓòÉΓòÉ 25. Index ΓòÉΓòÉΓòÉ

 !, in modules file                                Excluding directories
 #cvs.lock, removing                               Several developers
                                                   simultaneously attempting to
                                                   run CVS
 #cvs.lock, technical details                      CVS locks in the repository
 #cvs.rfl, and backups                             Backing up a repository
 #cvs.rfl, removing                                Several developers
                                                   simultaneously attempting to
                                                   run CVS
 #cvs.rfl, technical details                       CVS locks in the repository
 #cvs.tfl                                          CVS locks in the repository
 #cvs.wfl, removing                                Several developers
                                                   simultaneously attempting to
                                                   run CVS
 #cvs.wfl, technical details                       CVS locks in the repository
 &, in modules file                                Ampersand modules
 :ext:, setting up                                 Connecting with rsh
 :ext:, troubleshooting                            Trouble making a connection
                                                   to a CVS server
 :gserver:, setting up                             Direct connection with
                                                   GSSAPI
 :kserver:, setting up                             Direct connection with
                                                   kerberos
 :local:, setting up                               The Repository
 :pserver:, setting up                             Using the client with
                                                   password authentication
 :pserver:, troubleshooting                        Trouble making a connection
                                                   to a CVS server
 :server:, setting up                              Connecting with rsh
 :server:, troubleshooting                         Trouble making a connection
                                                   to a CVS server
 ┬╖# files                                          update output
 ┬╖bashrc, setting CVSROOT in                       Telling CVS where your
                                                   repository is
 ┬╖cshrc, setting CVSROOT in                        Telling CVS where your
                                                   repository is
 ┬╖profile, setting CVSROOT in                      Telling CVS where your
                                                   repository is
 ┬╖tcshrc, setting CVSROOT in                       Telling CVS where your
                                                   repository is
 -a, in modules file                               Alias modules
 -d, in modules file                               Module options
 -e, in modules file                               Module options
 -i, in modules file                               Module options
 -j (merging branches)                             Merging an entire branch
 -k (keyword substitution)                         Substitution modes
 -o, in modules file                               Module options
 -s, in modules file                               Module options
 -t, in modules file                               Module options
 -u, in modules file                               Module options
 .cvsrc file                                       Default options and the
                                                   ~/.cvsrc file
 /usr/local/cvsroot, as example repository         The Repository
 <<<<<<<                                           Conflicts example
 =======                                           Conflicts example
 >>>>>>>                                           Conflicts example
 abandoning work                                   How to edit a file which is
                                                   being watched
 Access a branch                                   Accessing branches
 add (subcommand)                                  Adding files to a directory
 Adding a tag                                      Tags--Symbolic revisions
 Adding files                                      Adding files to a directory
 Admin (subcommand)                                admin---Administration
 Administrative files (intro)                      The administrative files
 Administrative files (reference)                  Reference manual for
                                                   Administrative files
 Administrative files, editing them                Editing administrative files
 Alias modules                                     Alias modules
 ALL in commitinfo                                 Commitinfo
 Ampersand modules                                 Ampersand modules
 annotate (subcommand)                             Annotate command
 Atomic transactions, lack of                      Several developers
                                                   simultaneously attempting to
                                                   run CVS
 attic                                             The attic
 authenticated client, using                       Using the client with
                                                   password authentication
 authenticating server, setting up                 Setting up the server for
                                                   password authentication
 authentication, stream                            Global options
 Author keyword                                    Keyword List
 Automatically ignored files                       Ignoring files via cvsignore
 Avoiding editor invocation                        Common command options
 Backing up, repository                            Backing up a repository
 Base directory, in CVS directory                  How data is stored in the
                                                   working directory
 BASE, as reserved tag name                        Tags--Symbolic revisions
 BASE, special tag                                 Common command options
 Baserev file, in CVS directory                    How data is stored in the
                                                   working directory
 Baserev.tmp file, in CVS directory                How data is stored in the
                                                   working directory
 bill of materials                                 How your build system
                                                   interacts with CVS
 Binary files                                      Handling binary files
 Branch merge example                              Merging an entire branch
 Branch number                                     Revision numbers
                                                   Branches and revisions
 Branch, accessing                                 Accessing branches
 Branch, check out                                 Accessing branches
 Branch, creating a                                Creating a branch
 Branch, identifying                               Accessing branches
 Branch, retrieving                                Accessing branches
 Branch, vendor-                                   Tracking third-party sources
 Branches motivation                               What branches are good for
 Branches, copying changes between                 Branching and merging
 Branches, sticky                                  Accessing branches
 Branching                                         Branching and merging
 Bringing a file up to date                        Bringing a file up to date
 Bugs in this manual or CVS                        Dealing with bugs in CVS or
                                                   this manual
 Bugs, reporting                                   Dealing with bugs in CVS or
                                                   this manual
 builds                                            How your build system
                                                   interacts with CVS
 Changes, copying between branches                 Branching and merging
 Changing a log message                            admin options
 Check out a branch                                Accessing branches
 checked out copy, keeping                         Keeping a checked out copy
 Checkin program                                   Module options
 Checkin.prog file, in CVS directory               How data is stored in the
                                                   working directory
 Checking commits                                  Commitinfo
 Checking out source                               Getting the source
 Checkout (subcommand)                             checkout---Check out sources
                                                   for editing
 Checkout program                                  Module options
 checkout, as term for getting ready to edit       How to edit a file which is
                                                   being watched
 Checkout, example                                 Getting the source
 checkoutlist                                      How files are stored in the
                                                   CVSROOT directory
 choosing, reserved or unreserved checkouts        Choosing between reserved or
                                                   unreserved checkouts
 Cleaning up                                       Cleaning up
 Client/Server Operation                           Remote repositories
 Co (subcommand)                                   checkout---Check out sources
                                                   for editing
 Command reference                                 Quick reference to CVS
                                                   commands
 Command structure                                 Overall structure of CVS
                                                   commands
 comment leader                                    admin options
 Commit (subcommand)                               commit---Check files into
                                                   the repository
 Commit files                                      The commit support files
 Commit, when to                                   When to commit?
 Commitinfo                                        Commitinfo
 Committing changes                                Committing your changes
 Common options                                    Common command options
 Common syntax of info files                       The common syntax
 compatibility, between CVS versions               Compatibility between CVS
                                                   Versions
 COMSPEC, environment variable                     All environment variables
                                                   which affect CVS
 config, in CVSROOT                                The CVSROOT/config
                                                   configuration file
 Conflict markers                                  Conflicts example
 Conflict resolution                               Conflicts example
 Conflicts (merge example)                         Conflicts example
 Contributors (CVS program)                        What is CVS?
 Contributors (manual)                             Credits
 copying a repository                              Moving a repository
 Copying changes                                   Branching and merging
 Correcting a log message                          admin options
 Creating a branch                                 Creating a branch
 Creating a project                                Starting a project with CVS
 Creating a repository                             Creating a repository
 Credits (CVS program)                             What is CVS?
 Credits (manual)                                  Credits
 CVS 1.6, and watches                              Using watches with old
                                                   versions of CVS
 CVS command structure                             Overall structure of CVS
                                                   commands
 CVS directory, in repository                      The CVS directory in the
                                                   repository
 CVS directory, in working directory               How data is stored in the
                                                   working directory
 CVS passwd file                                   Setting up the server for
                                                   password authentication
 CVS, history of                                   What is CVS?
 CVS, introduction to                              What is CVS?
 CVS, versions of                                  Compatibility between CVS
                                                   Versions
 CVS/Base directory                                How data is stored in the
                                                   working directory
 CVS/Baserev file                                  How data is stored in the
                                                   working directory
 CVS/Baserev.tmp file                              How data is stored in the
                                                   working directory
 CVS/Checkin.prog file                             How data is stored in the
                                                   working directory
 CVS/Entries file                                  How data is stored in the
                                                   working directory
 CVS/Entries.Backup file                           How data is stored in the
                                                   working directory
 CVS/Entries.Log file                              How data is stored in the
                                                   working directory
 CVS/Entries.Static file                           How data is stored in the
                                                   working directory
 CVS/Notify file                                   How data is stored in the
                                                   working directory
 CVS/Notify.tmp file                               How data is stored in the
                                                   working directory
 CVS/Repository file                               How data is stored in the
                                                   working directory
 CVS/Root file                                     Telling CVS where your
                                                   repository is
 CVS/Tag file                                      How data is stored in the
                                                   working directory
 CVS/Template file                                 How data is stored in the
                                                   working directory
 CVS/Update.prog file                              How data is stored in the
                                                   working directory
 CVSEDITOR, environment variable                   Committing your changes
 cvsignore (admin file), global                    Ignoring files via cvsignore
 CVSIGNORE, environment variable                   All environment variables
                                                   which affect CVS
 CVSREAD, environment variable                     All environment variables
                                                   which affect CVS
 CVSREAD, overriding                               Global options
 cvsroot                                           The Repository
 CVSROOT (file)                                    Reference manual for
                                                   Administrative files
 CVSROOT, environment variable                     Telling CVS where your
                                                   repository is
 CVSROOT, module name                              The administrative files
 CVSROOT, multiple repositories                    Multiple repositories
 CVSROOT, overriding                               Global options
 CVSROOT, storage of files                         How files are stored in the
                                                   CVSROOT directory
 CVSROOT/config                                    The CVSROOT/config
                                                   configuration file
 CVSUMASK, environment variable                    File permissions
 cvswrappers (admin file)                          The cvswrappers file
 CVSWRAPPERS, environment variable                 The cvswrappers file
                                                   All environment variables
                                                   which affect CVS
 CVS_CLIENT_LOG, environment variable              All environment variables
                                                   which affect CVS
 CVS_CLIENT_PORT                                   Direct connection with
                                                   kerberos
 CVS_IGNORE_REMOTE_ROOT, environment variable      All environment variables
                                                   which affect CVS
 CVS_PASSFILE, environment variable                Using the client with
                                                   password authentication
 CVS_RCMD_PORT, environment variable               All environment variables
                                                   which affect CVS
 CVS_RSH, environment variable                     All environment variables
                                                   which affect CVS
 CVS_SERVER, environment variable                  Connecting with rsh
 CVS_SERVER_SLEEP, environment variable            All environment variables
                                                   which affect CVS
 Cyclic Software                                   Dealing with bugs in CVS or
                                                   this manual
 Date keyword                                      Keyword List
 Dates                                             Common command options
 dead state                                        The attic
 Decimal revision number                           Revision numbers
 DEFAULT in commitinfo                             Commitinfo
 DEFAULT in editinfo                               Editinfo
 DEFAULT in verifymsg                              Verifying log messages
 Defining a module                                 Defining the module
 Defining modules (intro)                          The administrative files
 Defining modules (reference manual)               The modules file
 Deleting files                                    Removing files
 Deleting revisions                                admin options
 Deleting sticky tags                              Sticky tags
 Descending directories                            Recursive behavior
 device nodes                                      Special Files
 Diff                                              Viewing differences
 Diff (subcommand)                                 diff---Show differences
                                                   between revisions
 Differences, merging                              Merging differences between
                                                   any two revisions
 Directories, moving                               Moving and renaming
                                                   directories
 directories, removing                             Removing directories
 Directory, descending                             Recursive behavior
 Disjoint repositories                             Multiple repositories
 Distributing log messages                         Loginfo
 driver.c (merge example)                          Conflicts example
 edit (subcommand)                                 How to edit a file which is
                                                   being watched
 editinfo (admin file)                             Editinfo
 Editing administrative files                      Editing administrative files
 Editing the modules file                          Defining the module
 Editor, avoiding invocation of                    Common command options
 EDITOR, environment variable                      Committing your changes
 EDITOR, overriding                                Global options
 Editor, specifying per module                     Editinfo
 editors (subcommand)                              Information about who is
                                                   watching and editing
 emerge                                            Conflicts example
 encryption                                        Global options
 Entries file, in CVS directory                    How data is stored in the
                                                   working directory
 Entries.Backup file, in CVS directory             How data is stored in the
                                                   working directory
 Entries.Log file, in CVS directory                How data is stored in the
                                                   working directory
 Entries.Static file, in CVS directory             How data is stored in the
                                                   working directory
 Environment variables                             All environment variables
                                                   which affect CVS
 Errors, reporting                                 Dealing with bugs in CVS or
                                                   this manual
 Example of a work-session                         A sample session
 Example of merge                                  Conflicts example
 Example, branch merge                             Merging an entire branch
 excluding directories, in modules file            Excluding directories
 exit status, of commitinfo                        Commitinfo
 exit status, of CVS                               CVS's exit status
 exit status, of editor                            Partial list of error
                                                   messages
 exit status, of taginfo                           User-defined logging
 exit status, of verifymsg                         Verifying log messages
 Export (subcommand)                               export---Export sources from
                                                   CVS, similar to checkout
 Export program                                    Module options
 Fetching source                                   Getting the source
 File had conflicts on merge                       File status
 File locking                                      Multiple developers
 File permissions, general                         File permissions
 File permissions, Windows-specific                File Permission issues
                                                   specific to Windows
 File status                                       File status
 Files, moving                                     Moving and renaming files
 Files, reference manual                           Reference manual for
                                                   Administrative files
 Fixing a log message                              admin options
 Forcing a tag match                               Common command options
 Form for log message                              Rcsinfo
 Format of CVS commands                            Overall structure of CVS
                                                   commands
 Getting started                                   A sample session
 Getting the source                                Getting the source
 Global cvsignore                                  Ignoring files via cvsignore
 Global options                                    Global options
 Group                                             File permissions
 GSSAPI                                            Direct connection with
                                                   GSSAPI
 hard links                                        Special Files
 HEAD, as reserved tag name                        Tags--Symbolic revisions
 HEAD, special tag                                 Common command options
 Header keyword                                    Keyword List
 History (subcommand)                              history---Show status of
                                                   files and users
 History browsing                                  History browsing
 History file                                      The history file
 History files                                     Where files are stored
                                                   within the repository
 History of CVS                                    What is CVS?
 HOME, environment variable                        All environment variables
                                                   which affect CVS
 HOMEDRIVE, environment variable                   All environment variables
                                                   which affect CVS
 HOMEPATH, environment variable                    All environment variables
                                                   which affect CVS
 Id keyword                                        Keyword List
 Ident (shell command)                             Using keywords
 Identifying a branch                              Accessing branches
 Identifying files                                 Keyword substitution
 Ignored files                                     Ignoring files via cvsignore
 Ignoring files                                    Ignoring files via cvsignore
 Import (subcommand)                               import---Import sources into
                                                   CVS, using vendor branches
 Importing files                                   Creating a directory tree
                                                   from a number of files
 Importing files, from other version control systems Creating Files From Other
                                                   Version Control Systems
 Importing modules                                 Importing a module for the
                                                   first time
 Index                                             Index
 Info files (syntax)                               The common syntax
 Informing others                                  Informing others about
                                                   commits
 init (subcommand)                                 Creating a repository
 installed images (VMS)                            File permissions
 Introduction to CVS                               What is CVS?
 Invoking CVS                                      Quick reference to CVS
                                                   commands
 Isolation                                         History browsing
 Join                                              Merging an entire branch
 keeping a checked out copy                        Keeping a checked out copy
 kerberos                                          Direct connection with
                                                   kerberos
 Keyword expansion                                 Keyword substitution
 Keyword List                                      Keyword List
 Keyword substitution                              Keyword substitution
 Kflag                                             Substitution modes
 kinit                                             Direct connection with
                                                   kerberos
 Known bugs in this manual or CVS                  Dealing with bugs in CVS or
                                                   this manual
 Layout of repository                              The Repository
 Left-hand options                                 Global options
 Linear development                                Revision numbers
 link, symbolic, importing                         import output
 List, mailing list                                What is CVS?
 Locally Added                                     File status
 Locally Modified                                  File status
 Locally Removed                                   File status
 Locker keyword                                    Keyword List
 Locking files                                     Multiple developers
 locks, cvs, and backups                           Backing up a repository
 locks, cvs, introduction                          Several developers
                                                   simultaneously attempting to
                                                   run CVS
 locks, cvs, technical details                     CVS locks in the repository
 Log (subcommand)                                  log---Print out log
                                                   information for files
 Log information, saving                           The history file
 Log keyword                                       Keyword List
 Log message entry                                 Committing your changes
 Log message template                              Rcsinfo
 Log message, correcting                           admin options
 log message, verifying                            Verifying log messages
 Log messages                                      Loginfo
 Log messages, editing                             Editinfo
 Login (subcommand)                                Using the client with
                                                   password authentication
 loginfo (admin file)                              Loginfo
 Logout (subcommand)                               Using the client with
                                                   password authentication
 Mail, automatic mail on commit                    Informing others about
                                                   commits
 Mailing list                                      What is CVS?
 Mailing log messages                              Loginfo
 Main trunk and branches                           Branching and merging
 make                                              How your build system
                                                   interacts with CVS
 Many repositories                                 Multiple repositories
 Markers, conflict                                 Conflicts example
 Merge, an example                                 Conflicts example
 Merge, branch example                             Merging an entire branch
 Merging                                           Branching and merging
 Merging a branch                                  Merging an entire branch
 Merging a file                                    Bringing a file up to date
 Merging two revisions                             Merging differences between
                                                   any two revisions
 mkmodules                                         Partial list of error
                                                   messages
 Modifications, copying between branches           Branching and merging
 Module status                                     Module options
 Module, defining                                  Defining the module
 Modules (admin file)                              The modules file
 Modules file                                      The administrative files
 Modules file, changing                            Defining the module
 modules.db                                        How files are stored in the
                                                   CVSROOT directory
 modules.dir                                       How files are stored in the
                                                   CVSROOT directory
 modules.pag                                       How files are stored in the
                                                   CVSROOT directory
 Motivation for branches                           What branches are good for
 moving a repository                               Moving a repository
 Moving directories                                Moving and renaming
                                                   directories
 Moving files                                      Moving and renaming files
 moving tags                                       tag options
 Multiple developers                               Multiple developers
 Multiple repositories                             Multiple repositories
 Name keyword                                      Keyword List
 Name, symbolic (tag)                              Tags--Symbolic revisions
 Needs Checkout                                    File status
 Needs Merge                                       File status
 Needs Patch                                       File status
 Newsgroups                                        What is CVS?
 notify (admin file)                               Telling CVS to notify you
 Notify file, in CVS directory                     How data is stored in the
                                                   working directory
 Notify.tmp file, in CVS directory                 How data is stored in the
                                                   working directory
 Number, branch                                    Revision numbers
                                                   Branches and revisions
 Number, revision-                                 Revision numbers
 option defaults                                   Default options and the
                                                   ~/.cvsrc file
 Options, global                                   Global options
 options, in modules file                          Module options
 Outdating revisions                               admin options
 Overlap                                           Bringing a file up to date
 Overriding CVSREAD                                Global options
 Overriding CVSROOT                                Global options
 Overriding EDITOR                                 Global options
 Overriding RCSBIN                                 Global options
 Overriding TMPDIR                                 Global options
 Overview                                          Overview
 ownership, saving in CVS                          Special Files
 Parallel repositories                             Multiple repositories
 passwd (admin file)                               Setting up the server for
                                                   password authentication
 password client, using                            Using the client with
                                                   password authentication
 password server, setting up                       Setting up the server for
                                                   password authentication
 PATH, environment variable                        All environment variables
                                                   which affect CVS
 Per-directory sticky tags/dates                   How data is stored in the
                                                   working directory
 Per-module editor                                 Editinfo
 permissions, general                              File permissions
 permissions, saving in CVS                        Special Files
 permissions, Windows-specific                     File Permission issues
                                                   specific to Windows
 Policy                                            When to commit?
 Precommit checking                                Commitinfo
 PreservePermissions, in CVSROOT/config            The CVSROOT/config
                                                   configuration file
 Pserver (subcommand)                              Setting up the server for
                                                   password authentication
 PVCS, importing files from                        Creating Files From Other
                                                   Version Control Systems
 RCS history files                                 Where files are stored
                                                   within the repository
 RCS revision numbers                              Tags--Symbolic revisions
 RCS, importing files from                         Creating Files From Other
                                                   Version Control Systems
 RCS-style locking                                 Multiple developers
 RCSBIN, in CVSROOT/config                         The CVSROOT/config
                                                   configuration file
 RCSBIN, overriding                                Global options
 RCSfile keyword                                   Keyword List
 rcsinfo (admin file)                              Rcsinfo
 Rdiff (subcommand)                                rdiff---'patch' format diffs
                                                   between releases
 read-only files, and -r                           Global options
 read-only files, and CVSREAD                      All environment variables
                                                   which affect CVS
 read-only files, and watches                      Telling CVS to watch certain
                                                   files
 read-only files, in repository                    File permissions
 Read-only mode                                    Global options
 read-only repository access                       Read-only repository access
 readers (admin file)                              Read-only repository access
 Recursive (directory descending)                  Recursive behavior
 Reference manual (files)                          Reference manual for
                                                   Administrative files
 Reference manual for variables                    All environment variables
                                                   which affect CVS
 Reference, commands                               Quick reference to CVS
                                                   commands
 regular expression syntax                         The common syntax
 Regular modules                                   Regular modules
 Release (subcommand)                              release---Indicate that a
                                                   Module is no longer in use
 Releases, revisions and versions                  Versions, revisions and
                                                   releases
 Releasing your working copy                       Cleaning up
 Remote repositories                               Remote repositories
 Remove (subcommand)                               Removing files
 Removing a change                                 Merging differences between
                                                   any two revisions
 removing directories                              Removing directories
 Removing files                                    Removing files
 Removing your working copy                        Cleaning up
 Renaming directories                              Moving and renaming
                                                   directories
 Renaming files                                    Moving and renaming files
 renaming tags                                     tag options
 Replacing a log message                           admin options
 Reporting bugs                                    Dealing with bugs in CVS or
                                                   this manual
 Repositories, multiple                            Multiple repositories
 Repositories, remote                              Remote repositories
 Repository (intro)                                The Repository
 Repository file, in CVS directory                 How data is stored in the
                                                   working directory
 Repository, backing up                            Backing up a repository
 Repository, example                               The Repository
 Repository, how data is stored                    How data is stored in the
                                                   repository
 repository, moving                                Moving a repository
 Repository, setting up                            Creating a repository
 reserved checkouts                                Multiple developers
 Resetting sticky tags                             Sticky tags
 Resolving a conflict                              Conflicts example
 Restoring old version of removed file             Sticky tags
 Resurrecting old version of dead file             Sticky tags
 Retrieve a branch                                 Accessing branches
 Retrieving an old revision using tags             Tags--Symbolic revisions
 reverting to repository version                   How to edit a file which is
                                                   being watched
 Revision keyword                                  Keyword List
 Revision management                               Revision management
 Revision numbers                                  Revision numbers
 Revision numbers (branches)                       Branches and revisions
 Revision tree                                     Revision numbers
 Revision tree, making branches                    Branching and merging
 Revisions, merging differences between            Merging differences between
                                                   any two revisions
 Revisions, versions and releases                  Versions, revisions and
                                                   releases
 Right-hand options                                Common command options
 Root file, in CVS directory                       Telling CVS where your
                                                   repository is
 rsh                                               Connecting with rsh
 Rtag (subcommand)                                 rtag---Add a symbolic tag to
                                                   a module
 rtag, creating a branch using                     Creating a branch
 Saving space                                      admin options
 SCCS, importing files from                        Creating Files From Other
                                                   Version Control Systems
 Security, file permissions in repository          File permissions
 security, GSSAPI                                  Direct connection with
                                                   GSSAPI
 security, kerberos                                Direct connection with
                                                   kerberos
 security, of pserver                              Security considerations with
                                                   password authentication
 security, setuid                                  File permissions
 server, CVS                                       Remote repositories
 server, temporary directories                     Temporary directories for
                                                   the server
 setgid                                            File permissions
 Setting up a repository                           Creating a repository
 setuid                                            File permissions
 Signum Support                                    Dealing with bugs in CVS or
                                                   this manual
 Source keyword                                    Keyword List
 Source, getting CVS source                        What is CVS?
 Source, getting from CVS                          Getting the source
 special files                                     Special Files
 Specifying dates                                  Common command options
 Spreading information                             Informing others about
                                                   commits
 Starting a project with CVS                       Starting a project with CVS
 State keyword                                     Keyword List
 Status of a file                                  File status
 Status of a module                                Module options
 sticky date                                       Sticky tags
 Sticky tags                                       Sticky tags
 Sticky tags, resetting                            Sticky tags
 Sticky tags/dates, per-directory                  How data is stored in the
                                                   working directory
 Storing log messages                              Loginfo
 stream authentication                             Global options
 Structure                                         Overall structure of CVS
                                                   commands
 Subdirectories                                    Recursive behavior
 Support, getting CVS support                      Dealing with bugs in CVS or
                                                   this manual
 symbolic link, importing                          import output
 symbolic links                                    Special Files
 Symbolic name (tag)                               Tags--Symbolic revisions
 Syntax of info files                              The common syntax
 SystemAuth, in CVSROOT/config                     The CVSROOT/config
                                                   configuration file
 Tag (subcommand)                                  tag---Add a symbolic tag to
                                                   checked out versions of
                                                   files
 Tag file, in CVS directory                        How data is stored in the
                                                   working directory
 Tag program                                       Module options
 tag, command, introduction                        Tags--Symbolic revisions
 tag, creating a branch using                      Creating a branch
 tag, example                                      Tags--Symbolic revisions
 Tag, retrieving old revisions                     Tags--Symbolic revisions
 Tag, symbolic name                                Tags--Symbolic revisions
 taginfo                                           User-defined logging
 Tags                                              Tags--Symbolic revisions
 tags, renaming                                    tag options
 Tags, sticky                                      Sticky tags
 tc, Trivial Compiler (example)                    A sample session
 Team of developers                                Multiple developers
 TEMP, environment variable                        All environment variables
                                                   which affect CVS
 Template file, in CVS directory                   How data is stored in the
                                                   working directory
 Template for log message                          Rcsinfo
 temporary directories, and server                 Temporary directories for
                                                   the server
 temporary files, location of                      All environment variables
                                                   which affect CVS
 Third-party sources                               Tracking third-party sources
 Time                                              Common command options
 timezone, in input                                Common command options
 timezone, in output                               log---Print out log
                                                   information for files
 TMP, environment variable                         All environment variables
                                                   which affect CVS
 TMPDIR, environment variable                      All environment variables
                                                   which affect CVS
 TMPDIR, overriding                                Global options
 TopLevelAdmin, in CVSROOT/config                  The CVSROOT/config
                                                   configuration file
 Trace                                             Global options
 Traceability                                      History browsing
 Tracking sources                                  Tracking third-party sources
 Transactions, atomic, lack of                     Several developers
                                                   simultaneously attempting to
                                                   run CVS
 Trivial Compiler (example)                        A sample session
 Typical repository                                The Repository
 umask, for repository files                       File permissions
 Undoing a change                                  Merging differences between
                                                   any two revisions
 unedit (subcommand)                               How to edit a file which is
                                                   being watched
 Unknown                                           File status
 unreserved checkouts                              Multiple developers
 Up-to-date                                        File status
 Update (subcommand)                               update---Bring work tree in
                                                   sync with repository
 Update program                                    Module options
 update, introduction                              Bringing a file up to date
 update, to display file status                    File status
 Update.prog file, in CVS directory                How data is stored in the
                                                   working directory
 Updating a file                                   Bringing a file up to date
 user aliases                                      Setting up the server for
                                                   password authentication
 users (admin file)                                Telling CVS to notify you
 Vendor                                            Tracking third-party sources
 Vendor branch                                     Tracking third-party sources
 verifymsg (admin file)                            Verifying log messages
 versions, of CVS                                  Compatibility between CVS
                                                   Versions
 Versions, revisions and releases                  Versions, revisions and
                                                   releases
 Viewing differences                               Viewing differences
 watch add (subcommand)                            Telling CVS to notify you
 watch off (subcommand)                            Telling CVS to watch certain
                                                   files
 watch on (subcommand)                             Telling CVS to watch certain
                                                   files
 watch remove (subcommand)                         Telling CVS to notify you
 watchers (subcommand)                             Information about who is
                                                   watching and editing
 Watches                                           Mechanisms to track who is
                                                   editing files
 Wdiff (import example)                            Importing a module for the
                                                   first time
 web pages, maintaining with CVS                   Keeping a checked out copy
 What (shell command)                              Using keywords
 What branches are good for                        What branches are good for
 What is CVS not?                                  What is CVS not?
 What is CVS?                                      What is CVS?
 When to commit                                    When to commit?
 Windows, and permissions                          File Permission issues
                                                   specific to Windows
 Work-session, example of                          A sample session
 Working copy                                      Multiple developers
 Working copy, removing                            Cleaning up
 Wrappers                                          The cvswrappers file
 writers (admin file)                              Read-only repository access
 zone, time, in input                              Common command options
 zone, time, in output                             log---Print out log
                                                   information for files
 __ files (VMS)                                    update output