This is Info file ../info/emacs, produced by Makeinfo-1.54 from the input file emacs.texi. File: emacs, Node: Change Logs and VC, Next: Comparing Versions, Prev: Log Entries, Up: Version Control Change Logs and VC ------------------ If you use RCS for a program and also maintain a change log file for it (*note Change Log::.), you can generate change log entries automatically from the version control log entries: `C-x v a' Visit the current directory's change log file and create new entries for versions checked in since the most recent entry in the change log file (`vc-update-change-log'). This command works with RCS only; it does not work with SCCS. For example, suppose the first line of `ChangeLog' is dated 10 April 1992, and that the only check-in since then was by Nathaniel Bowditch to `rcs2log' on 8 May 1992 with log text `Ignore log messages that start with `#'.'. Then `C-x v a' visits `ChangeLog' and inserts text like this: Fri May 8 21:45:00 1992 Nathaniel Bowditch (nat@apn.org) * rcs2log: Ignore log messages that start with `#'. You can then edit the new change log entry further as you wish. Normally, the log entry for file `foo' is displayed as `* foo: TEXT OF LOG ENTRY'. The `:' after `foo' is omitted if the text of the log entry starts with `(FUNCTIONNAME): '. For example, if the log entry for `vc.el' is `(vc-do-command): Check call-process status.', then the text in `ChangeLog' looks like this: Wed May 6 10:53:00 1992 Nathaniel Bowditch (nat@apn.org) * vc.el (vc-do-command): Check call-process status. When `C-x v a' adds several change log entries at once, it groups related log entries together if they all are checked in by the same author at nearly the same time. If the log entries for several such files all have the same text, it coalesces them into a single entry. For example, suppose the most recent checkins have the following log entries: For `vc.texinfo': Fix expansion typos. For `vc.el': Don't call expand-file-name. For `vc-hooks.el': Don't call expand-file-name. They appear like this in `ChangeLog': Wed Apr 1 08:57:59 1992 Nathaniel Bowditch (nat@apn.org) * vc.texinfo: Fix expansion typos. * vc.el, vc-hooks.el: Don't call expand-file-name. Normally, `C-x v a' separates log entries by a blank line, but you can mark several related log entries to be clumped together (without an intervening blank line) by starting the text of each related log entry with a label of the form `{CLUMPNAME} '. The label itself is not copied to `ChangeLog'. For example, suppose the log entries are: For `vc.texinfo': {expand} Fix expansion typos. For `vc.el': {expand} Don't call expand-file-name. For `vc-hooks.el': {expand} Don't call expand-file-name. Then the text in `ChangeLog' looks like this: Wed Apr 1 08:57:59 1992 Nathaniel Bowditch (nat@apn.org) * vc.texinfo: Fix expansion typos. * vc.el, vc-hooks.el: Don't call expand-file-name. A log entry whose text begins with `#' is not copied to `ChangeLog'. For example, if you merely fix some misspellings in comments, you can log the change with an entry beginning with `#' to avoid putting such trivia into `ChangeLog'. File: emacs, Node: Comparing Versions, Next: VC Status, Prev: Change Logs and VC, Up: Version Control Comparing Versions ------------------ To compare two versions of a file, use the command `C-x v =' (`vc-diff'). Plain `C-x v =' compares the current buffer contents (saving them in the file if necessary) with the last checked-in version of the file. With a prefix argument, `C-x v =' reads a file name and two version numbers, then compares those versions of the specified file. If you supply a directory name instead of the name of a work file, this command compares the two specified versions of all registered files in that directory and its subdirectories. You can also specify a snapshot name (*note Snapshots::.) instead of one or both version numbers. You can specify a checked-in version by its number; you can specify the most recent checked-in version with an empty version number. This command works by running the `diff' utility, getting the options from the variable `diff-switches'. It displays the output in a special buffer in another window. Unlike the `M-x diff' command, `C-x v =' does not try to find the changes in the old and new versions. This is because one or both versions normally do not exist as files. They exist only in the records of the master file. *Note Comparing Files::, for more information about `M-x diff'. File: emacs, Node: VC Status, Next: Renaming and VC, Prev: Comparing Versions, Up: Version Control VC Status Commands ------------------ To view the detailed version control status and history of a file, type `C-x v l' (`vc-print-log'). It displays the history of changes to the current file, including the text of the log entries. The output appears in a separate window. When you are working on a large program, it's often useful to find all the files that are currently locked, or all the files maintained in version control at all. You can use `C-x v d' (`vc-directory') to show all the locked files in or beneath the current directory. This includes all files that are locked by any user. `C-u C-x v d' lists all files in or beneath the current directory that are maintained with version control. The list of files is displayed as a buffer that uses an augmented Dired mode. The names of the users locking various files are shown (in parentheses) in place of the owner and group. All the normal Dired commands work in this buffer. Most interactive VC commands work also, and apply to the file name on the current line. The `vc-next-action' command, when used in the augmented Dired buffer, operates on all the marked files (or the file on the current line). If it operates on more than one file, it handles each file according to its current state; thus, it may check in one file and check in another (which is already checked out). If it has to check in any files, it reads a single log entry, then uses that text for all the files being checked in. This can be convenient for registering or checking in several files at once, as part of the same change. File: emacs, Node: Renaming and VC, Next: Snapshots, Prev: VC Status, Up: Version Control Renaming VC Work Files and Master Files --------------------------------------- When you rename a registered file, you must also rename its master file correspondingly to get proper results. Use `vc-rename-file' to rename the source file as you specify, and rename its master file accordingly. It also updates any snapshots (*note Snapshots::.) that mention the file, so that they use the new name; despite this, the snapshot thus modified may not completely work (*note Snapshot Caveats::.). You cannot use `vc-rename-file' on a file that is locked by someone else. File: emacs, Node: Snapshots, Next: Version Headers, Prev: Renaming and VC, Up: Version Control Snapshots --------- A "snapshot" is a named set of file versions (one for each registered file) that you can treat as a unit. One important kind of snapshot is a "release", a (theoretically) stable version of the system that is ready for distribution to users. * Menu: * Making Snapshots:: The snapshot facilities. * Snapshot Caveats:: Things to be careful of when using snapshots. File: emacs, Node: Making Snapshots, Next: Snapshot Caveats, Up: Snapshots Making and Using Snapshots .......................... There are two basic commands for snapshots; one makes a snapshot with a given name, the other retrieves a named snapshot. `C-x v s NAME RET' Define the last saved versions of every registered file in or under the current directory as a snapshot named NAME (`vc-create-snapshot'). `C-x v r NAME RET' Check out all registered files at or below the current directory level using whatever versions correspond to the snapshot NAME (`vc-retrieve-snapshot'). This command reports an error if any files are locked at or below the current directory, without changing anything; this is to avoid overwriting work in progress. A snapshot uses a very small amount of resources--just enough to record the list of file names and which version belongs to the snapshot. Thus, you need not hesitate to create snapshots whenever they are useful. You can give a snapshot name as an argument to `C-x v =' (*note Comparing Versions::.). Thus, you can use it to compare a snapshot against the current files, or two snapshots against each other, or a snapshot against a named version. File: emacs, Node: Snapshot Caveats, Prev: Making Snapshots, Up: Snapshots Snapshot Caveats ................ VC's snapshot facilities are modeled on RCS's named-configuration support. They use RCS's native facilities for this, so under VC snapshots made using RCS are visible even when you bypass VC. For SCCS, VC implements snapshots itself. The files it uses contain name/file/version-number triples. These snapshots are visible only through VC. File renaming and deletion can create some difficulties with snapshots. This is not a VC-specific problem, but a general design issue in version control systems that no one has solved very well yet. If you rename a registered file, you need to rename its master along with it (the command `vc-rename-file' does this automatically). If you are using SCCS, you must also update the records of the snapshot, to mention the file by its new name (`vc-rename-file' does this, too). An old snapshot that refers to a master file that no longer exists under the recorded name is invalid; VC can no longer retrieve it. It would be beyond the scope of this manual to explain enough about RCS and SCCS to explain how to update the snapshots by hand. Using `vc-rename-file' makes the snapshot remain valid for retrieval, but it does not solve all problems. For example, some of the files in the program probably refer to others by name. At the very least, the makefile probably mentions the file that you renamed. If you retrieve an old snapshot, the renamed file is retrieved under its new name, which is not the name that the makefile expects. So the program won't really work as retrieved. File: emacs, Node: Version Headers, Prev: Snapshots, Up: Version Control Inserting Version Control Headers --------------------------------- Sometimes it is convenient to put version identification strings directly into working files. Certain special strings called "version headers" are replaced in each successive version by the number of that version. You can use the `C-x v h' command (`vc-insert-headers') to insert a suitable header string. `C-x v h' Insert headers in a file for use with your version-control system. The default header string is `$Id$' for RCS and `%W%' for SCCS. You can specify other headers to insert by setting the variable `vc-header-alist'. Its value is a list of elements of the form `(PROGRAM . STRING)' where PROGRAM is `RCS' or `SCCS' and STRING is the string to use. Instead of a single string, you can specify a list of strings; then each string in the list is inserted as a separate header on a line of its own. It is often necessary to use "superfluous" backslashes when writing the strings that you put in this variable. This is to prevent the string in the constant from being interpreted as a header itself if the Emacs Lisp file containing it is maintained with version control. Each header is inserted surrounded by tabs, inside comment delimiters, on a new line at the start of the buffer. Normally the ordinary comment start and comment end strings of the current mode are used, but for certain modes, there are special comment delimiters for this purpose; the variable `vc-comment-alist' specifies them. Each element of this list has the form `(MODE STARTER ENDER)'. The variable `vc-static-header-alist' specifies further strings to add based on the name of the buffer. Its value should be a list of elements of the form `(REGEXP . FORMAT)'. Whenever REGEXP matches the buffer name, FORMAT is inserted as part of the header. A header line is inserted for each element that matches the buffer name, and for each string specified by `vc-header-alist'. The header line is made by processing the string from `vc-header-alist' with the format taken from the element. The default value for `vc-static-header-alist' is: (("\\.c$" . "\n#ifndef lint\nstatic char vcid[] = \"\%s\";\n\ #endif /* lint */\n")) which specifies insertion of a string of this form: #ifndef lint static char vcid[] = "STRING"; #endif /* lint */ File: emacs, Node: ListDir, Next: Comparing Files, Prev: Version Control, Up: Files Listing a File Directory ======================== The file system groups files into "directories". A "directory listing" is a list of all the files in a directory. Emacs provides directory listings in brief format (file names only) and verbose format (sizes, dates, and authors included). `C-x C-d DIR-OR-PATTERN' Print a brief directory listing (`list-directory'). `C-u C-x C-d DIR-OR-PATTERN' Print a verbose directory listing. The command to display a directory listing is `C-x C-d' (`list-directory'). It reads using the minibuffer a file name which is either a directory to be listed or a wildcard-containing pattern for the files to be listed. For example, C-x C-d /u2/emacs/etc RET lists all the files in directory `/u2/emacs/etc'. An example of specifying a file name pattern is C-x C-d /u2/emacs/src/*.c RET Normally, `C-x C-d' prints a brief directory listing containing just file names. A numeric argument (regardless of value) tells it to print a verbose listing (like `ls -l'). The text of a directory listing is obtained by running `ls' in an inferior process. Two Emacs variables control the switches passed to `ls': `list-directory-brief-switches' is a string giving the switches to use in brief listings (`"-CF"' by default), and `list-directory-verbose-switches' is a string giving the switches to use in a verbose listing (`"-l"' by default). File: emacs, Node: Comparing Files, Next: Misc File Ops, Prev: ListDir, Up: Files Comparing Files =============== The command `M-x diff' compares two files, displaying the differences in an Emacs buffer named `*Diff*'. It works by running the `diff' program, using options taken from the variable `diff-switches', whose value should be a string. The buffer `*Diff*' has Compilation mode as its major mode, so you can use `C-x `' to visit successive changed locations in the two source files. You can also move to a particular hunk of changes and type `C-c C-c' to find the corresponding source location. You can also use the other special commands of Compilation mode: SPC and DEL for scrolling, and `M-p' and `M-n' for cursor motion. *Note Compilation::. The command `M-x diff-backup' compares a specified file with its most recent backup. If you specify the name of a backup file, `diff-backup' compares it with the source file that it is a backup of. The command `M-x compare-windows' compares the text in the current window with that in the next window. Comparison starts at point in each window. Point moves forward in each window, a character at a time in each window, until the next characters in the two windows are different. Then the command is finished. For more information about windows in Emacs, *Note Windows::. With a numeric argument, `compare-windows' ignores changes in whitespace. If the variable `compare-ignore-case' is non-`nil', it ignores differences in case as well. See also *Note Emerge::, for convenient facilities for merging two similar files. File: emacs, Node: Misc File Ops, Prev: Comparing Files, Up: Files Miscellaneous File Operations ============================= Emacs has commands for performing many other operations on files. All operate on one file; they do not accept wild card file names. `M-x view-file' allows you to scan or read a file by sequential screenfuls. It reads a file name argument using the minibuffer. After reading the file into an Emacs buffer, `view-file' displays the beginning. You can then type SPC to scroll forward one windowful, or DEL to scroll backward. Various other commands are provided for moving around in the file, but none for changing it; type `C-h' while viewing for a list of them. They are mostly the same as normal Emacs cursor motion commands. To exit from viewing, type `C-c'. The commands for viewing are defined by a special major mode called View mode. A related command, `M-x view-buffer', views a buffer already present in Emacs. *Note Misc Buffer::. `M-x insert-file' inserts a copy of the contents of the specified file into the current buffer at point, leaving point unchanged before the contents and the mark after them. `M-x write-region' is the inverse of `M-x insert-file'; it copies the contents of the region into the specified file. `M-x append-to-file' adds the text of the region to the end of the specified file. *Note Accumulating Text::. `M-x delete-file' deletes the specified file, like the `rm' command in the shell. If you are deleting many files in one directory, it may be more convenient to use Dired (*note Dired::.). `M-x rename-file' reads two file names OLD and NEW using the minibuffer, then renames file OLD as NEW. If a file named NEW already exists, you must confirm with `yes' or renaming is not done; this is because renaming causes the old meaning of the name NEW to be lost. If OLD and NEW are on different file systems, the file OLD is copied and deleted. The similar command `M-x add-name-to-file' is used to add an additional name to an existing file without removing its old name. The new name must belong on the same file system that the file is on. `M-x copy-file' reads the file OLD and writes a new file named NEW with the same contents. Confirmation is required if a file named NEW already exists, because copying has the consequence of overwriting the old contents of the file NEW. `M-x make-symbolic-link' reads two file names OLD and LINKNAME, then creates a symbolic link named LINKNAME and pointing at OLD. The effect is that future attempts to open file LINKNAME will refer to whatever file is named OLD at the time the opening is done, or will get an error if the name OLD is not in use at that time. This command does not expand the argument FILENAME, so that it allows you to specify a relative name as the target of the link. Confirmation is required when creating the link if LINKNAME is in use. Note that not all systems support symbolic links. File: emacs, Node: Buffers, Next: Windows, Prev: Files, Up: Top Using Multiple Buffers ********************** The text you are editing in Emacs resides in an object called a "buffer". Each time you visit a file, a buffer is created to hold the file's text. Each time you invoke Dired, a buffer is created to hold the directory listing. If you send a message with `C-x m', a buffer named `*mail*' is used to hold the text of the message. When you ask for a command's documentation, that appears in a buffer called `*Help*'. At any time, one and only one buffer is "selected". It is also called the "current buffer". Often we say that a command operates on "the buffer" as if there were only one; but really this means that the command operates on the selected buffer (most commands do). When Emacs has multiple windows, each window has a chosen buffer which is displayed there, but at any time only one of the windows is selected and its chosen buffer is the selected buffer. Each window's mode line displays the name of the buffer that the window is displaying (*note Windows::.). Each buffer has a name, which can be of any length, and you can select any buffer by giving its name. Most buffers are made by visiting files, and their names are derived from the files' names. But you can also create an empty buffer with any name you want. A newly started Emacs has a buffer named `*scratch*' which can be used for evaluating Lisp expressions in Emacs. The distinction between upper and lower case matters in buffer names. Each buffer records individually what file it is visiting, whether it is modified, and what major mode and minor modes are in effect in it (*note Major Modes::.). Any Emacs variable can be made "local to" a particular buffer, meaning its value in that buffer can be different from the value in other buffers. *Note Locals::. * Menu: * Select Buffer:: Creating a new buffer or reselecting an old one. * List Buffers:: Getting a list of buffers that exist. * Misc Buffer:: Renaming; changing read-onliness; copying text. * Kill Buffer:: Killing buffers you no longer need. * Several Buffers:: How to go through the list of all buffers and operate variously on several of them. File: emacs, Node: Select Buffer, Next: List Buffers, Up: Buffers Creating and Selecting Buffers ============================== `C-x b BUFFER RET' Select or create a buffer named BUFFER (`switch-to-buffer'). `C-x 4 b BUFFER RET' Similar, but select BUFFER in another window (`switch-to-buffer-other-window'). To select the buffer named BUFNAME, type `C-x b BUFNAME RET'. This runs the command `switch-to-buffer' with argument BUFNAME. You can use completion on an abbreviation for the buffer name you want (*note Completion::.). An empty argument to `C-x b' specifies the most recently selected buffer that is not displayed in any window. Most buffers are created by visiting files, or by Emacs commands that want to display some text, but you can also create a buffer explicitly by typing `C-x b BUFNAME RET'. This makes a new, empty buffer which is not visiting any file, and selects it for editing. Such buffers are used for making notes to yourself. If you try to save one, you are asked for the file name to use. The new buffer's major mode is determined by the value of `default-major-mode' (*note Major Modes::.). Note that `C-x C-f', and any other command for visiting a file, can also be used to switch buffers. *Note Visiting::. File: emacs, Node: List Buffers, Next: Misc Buffer, Prev: Select Buffer, Up: Buffers Listing Existing Buffers ======================== `C-x C-b' List the existing buffers (`list-buffers'). To print a list of all the buffers that exist, type `C-x C-b'. Each line in the list shows one buffer's name, major mode and visited file. The buffers are listed in the order, most recently visited first. `*' at the beginning of a line indicates the buffer is "modified". If several buffers are modified, it may be time to save some with `C-x s' (*note Saving::.). `%' indicates a read-only buffer. `.' marks the selected buffer. Here is an example of a buffer list: MR Buffer Size Mode File -- ------ ---- ---- ---- .* emacs.tex 383402 Texinfo /u2/emacs/man/emacs.tex *Help* 1287 Fundamental files.el 23076 Emacs-Lisp /u2/emacs/lisp/files.el % RMAIL 64042 RMAIL /u/rms/RMAIL *% man 747 Dired /u2/emacs/man/ net.emacs 343885 Fundamental /u/rms/net.emacs fileio.c 27691 C /u2/emacs/src/fileio.c NEWS 67340 Text /u2/emacs/etc/NEWS *scratch* 0 Lisp Interaction Note that the buffer `*Help*' was made by a help request; it is not visiting any file. The buffer `man' was made by Dired on the directory `/u2/emacs/man/'. File: emacs, Node: Misc Buffer, Next: Kill Buffer, Prev: List Buffers, Up: Buffers Miscellaneous Buffer Operations =============================== `C-x C-q' Toggle read-only status of buffer (`toggle-read-only'). `M-x rename-buffer RET NAME RET' Change the name of the current buffer. `M-x rename-uniquely' Rename the current buffer by adding `' to the end. `M-x view-buffer RET BUFFER RET' Scroll through buffer BUFFER. A buffer can be "read-only", which means that commands to change its contents are not allowed. The mode line indicates read-only buffers with `%%' near the left margin. Read-only buffers are made by subsystems such as Dired and Rmail that have special commands to operate on the text; also if you visit a file that is protected so you cannot write it. If you wish to make changes in a read-only buffer, use the command `C-x C-q' (`vc-toggle-read-only'). It makes a read-only buffer writable, and makes a writable buffer read-only. This works by setting the variable `buffer-read-only', which has a local value in each buffer and makes the buffer read-only if its value is non-`nil'. If the file is maintained with version control, `C-x C-q' works through the version control system to change the read-only status of the buffer. `M-x rename-buffer' changes the name of the current buffer. Specify the new name as a minibuffer argument. There is no default. If you specify a name that is in use for some other buffer, an error happens and no renaming is done. `M-x rename-uniquely' renames the current buffer to a similar name with a numeric suffix added to make it both different and unique. This command does not need an argument. It is useful for creating multiple shell buffers: if you rename the `*Shell*', then do `M-x shell' again, it makes a new shell buffer named `*Shell*'; meanwhile, the old shell buffer continues to exist under its altered name. This method is also good for mail buffers, compilation buffers, and any Emacs feature which creates a special buffer with a particular name. `M-x view-buffer' is much like `M-x view-file' (*note Misc File Ops::.) except that it examines an already existing Emacs buffer. View mode provides commands for scrolling through the buffer conveniently but not for changing it. When you exit View mode, the value of point that resulted from your perusal remains in effect. The commands `M-x append-to-buffer' and `M-x insert-buffer' can be used to copy text from one buffer to another. *Note Accumulating Text::. File: emacs, Node: Kill Buffer, Next: Several Buffers, Prev: Misc Buffer, Up: Buffers Killing Buffers =============== If you continue an Emacs session for a while, you may accumulate a large number of buffers. You may then find it convenient to "kill" the buffers you no longer need. On most operating systems, killing a buffer releases its space back to the operating system so that other programs can use it. There are several commands for killing buffers: `C-x k BUFNAME RET' Kill buffer BUFNAME (`kill-buffer'). `M-x kill-some-buffers' Offer to kill each buffer, one by one. `C-x k' (`kill-buffer') kills one buffer, whose name you specify in the minibuffer. The default, used if you type just RET in the minibuffer, is to kill the current buffer. If you kill the current buffer, another buffer is selected; one that has been selected recently but does not appear in any window now. If you ask to kill a buffer that is modified (has unsaved editing), then you must confirm with `yes' before the buffer is killed. The command `M-x kill-some-buffers' asks about each buffer, one by one. An answer of `y' means to kill the buffer. Killing the current buffer or a buffer containing unsaved changes selects a new buffer or asks for confirmation just like `kill-buffer'. If you want to do something special every time a buffer is killed, you can add hook functions to the hook `kill-buffer-hook' (*note Hooks::.). File: emacs, Node: Several Buffers, Prev: Kill Buffer, Up: Buffers Operating on Several Buffers ============================ The "buffer-menu" facility is like a "Dired for buffers"; it allows you to request operations on various Emacs buffers by editing an Emacs buffer containing a list of them. You can save buffers, kill them (here called "deleting" them, for consistency with Dired), or display them. `M-x buffer-menu' Begin editing a buffer listing all Emacs buffers. The command `buffer-menu' writes a list of all Emacs buffers into the buffer `*Buffer List*', and selects that buffer in Buffer Menu mode. The buffer is read-only, and can be changed only through the special commands described in this section. The usual Emacs cursor motion commands can be used in the `*Buffer List*' buffer. The following commands apply to the buffer described on the current line. Request to delete (kill) the buffer, then move down. The request shows as a `D' on the line, before the buffer name. Requested deletions take place when you type the `x' command. `C-d' Like `d' but move up afterwards instead of down. Request to save the buffer. The request shows as an `S' on the line. Requested saves take place when you type the `x' command. You may request both saving and deletion for the same buffer. Perform previously requested deletions and saves. Remove any request made for the current line, and move down. `DEL' Move to previous line and remove any request made for that line. The `d', `s' and `u' commands to add or remove flags also move down a line. They accept a numeric argument as a repeat count. These commands operate immediately on the buffer listed on the current line: Mark the buffer "unmodified". The command `~' does this immediately when you type it. Toggle the buffer's read-only flag. The command `%' does this immediately when you type it. Visit the buffer as a tag table. There are also commands to select another buffer or buffers: Quit the buffer menu--immediately display the most recent formerly visible buffer in its place. Immediately select this line's buffer in place of the `*Buffer List*' buffer. Immediately select this line's buffer in another window as if by `C-x 4 b', leaving `*Buffer List*' visible. `C-o' Immediately display this line's buffer in another window, but don't select the window. Immediately select this line's buffer in a full-screen window. Immediately set up two windows, with this line's buffer in one, and the previously selected buffer (aside from the buffer `*Buffer List*') in the other. Mark this line's buffer to be displayed in another window if the `q' command is used. The request shows as a `>' at the beginning of the line. The same buffer may not have both a delete request and a display request. Immediately select this line's buffer, and also display in other windows any buffers previously marked with the `m' command. If you have not marked any buffers, this command is equivalent to `1'. All that `buffer-menu' does directly is create and select a suitable buffer, and turn on Buffer Menu mode. Everything else described above is implemented by the special commands provided in Buffer Menu mode. One consequence of this is that you can switch from the `*Buffer List*' buffer to another Emacs buffer, and edit there. You can reselect the `buffer-menu' buffer later, to perform the operations already requested, or you can kill it, or pay no further attention to it. The only difference between `buffer-menu' and `list-buffers' is that `buffer-menu' selects the `*Buffer List*' buffer and `list-buffers' does not. If you run `list-buffers' (that is, type `C-x C-b') and select the buffer list manually, you can use all of the commands described here. The buffer `*Buffer List*' is not updated automatically; its contents are just text. If you have created, deleted or renamed buffers, the way to update `*Buffer List*' to show what you have done is to repeat the `buffer-menu' command. File: emacs, Node: Windows, Next: Frames, Prev: Buffers, Up: Top Multiple Windows **************** Emacs can split a frame into two or many windows. Multiple windows can display parts of different buffers, or different parts of one buffer. Multiple frames always imply multiple windows, because each window belongs to one and only one frame. * Menu: * Basic Window:: Introduction to Emacs windows. * Split Window:: New windows are made by splitting existing windows. * Other Window:: Moving to another window or doing something to it. * Pop Up Window:: Finding a file or buffer in another window. * Change Window:: Deleting windows and changing their sizes. File: emacs, Node: Basic Window, Next: Split Window, Prev: Windows, Up: Windows Concepts of Emacs Windows ========================= When multiple windows are being displayed, each window has an Emacs buffer designated for display in it. The same buffer may appear in more than one window; if it does, any changes in its text are displayed in all the windows where it appears. But the windows showing the same buffer can show different parts of it, because each window has its own value of point. At any time, one of the windows is the "selected window"; the buffer this window is displaying is the current buffer. The terminal's cursor shows the location of point in this window. Each other window has a location of point as well, but since the terminal has only one cursor there is no way to show where those locations are. When you make multiple frames, each frame has a cursor which appears in the frame's selected window. Commands to move point affect the value of point for the selected Emacs window only. They do not change the value of point in any other Emacs window, even one showing the same buffer. The same is true for commands such as `C-x b' to change the selected buffer in the selected window; they do not affect other windows at all. However, there are other commands such as `C-x 4 b' that select a different window and switch buffers in it. Also, all commands that display information in a window, including (for example) `C-h f' (`describe-function') and `C-x C-b' (`list-buffers'), work by switching buffers in a nonselected window without affecting the selected window. When multiple windows show the same buffer, they can have different regions, because they can have different values of point. This means that in Transient Mark mode, each window highlights a different part of the buffer. The part that is highlighted in the selected window is the region that editing commands use. Each window has its own mode line, which displays the buffer name, modification status and major and minor modes of the buffer that is displayed in the window. *Note Mode Line::, for full details on the mode line. File: emacs, Node: Split Window, Next: Other Window, Prev: Basic Window, Up: Windows Splitting Windows ================= `C-x 2' Split the selected window into two windows, one above the other (`split-window-vertically'). `C-x 3' Split the selected window into two windows positioned side by side (`split-window-horizontally'). The command `C-x 2' (`split-window-vertically') breaks the selected window into two windows, one above the other. Both windows start out displaying the same buffer, with the same value of point. By default the two windows each get half the height of the window that was split; a numeric argument specifies how many lines to give to the top window. `C-x 3' (`split-window-horizontally') breaks the selected window into two side-by-side windows. A numeric argument specifies how many columns to give the one on the left. A line of vertical bars separates the two windows. Windows that are not the full width of the screen have mode lines, but they are truncated; also, they do not always appear in inverse video, because the Emacs display routines have not been taught how to display a region of inverse video that is only part of a line on the screen. When a window is less than the full width, text lines too long to fit are frequent. Continuing all those lines might be confusing. The variable `truncate-partial-width-windows' can be set non-`nil' to force truncation in all windows less than the full width of the screen, independent of the buffer being displayed and its value for `truncate-lines'. *Note Continuation Lines::. Horizontal scrolling is often used in side-by-side windows. *Note Display::. If `split-window-keep-point' is non-nil, `C-x 2' tries to avoid shifting any text on the screen by putting point in whichever window happens to contain the screen line the cursor is already on. The default is that `split-window-keep-point' is non-nil on slow terminals. File: emacs, Node: Other Window, Next: Pop Up Window, Prev: Split Window, Up: Windows Using Other Windows =================== `C-x o' Select another window (`other-window'). That is `o', not zero. `C-M-v' Scroll the next window (`scroll-other-window'). `M-x compare-windows' Find next place where the text in the selected window does not match the text in the next window. To select a different window, use `C-x o' (`other-window'). That is an `o', for `other', not a zero. When there are more than two windows, this command moves through all the windows in a cyclic order, generally top to bottom and left to right. After the rightmost and bottommost window, it goes back to the one at the upper left corner. A numeric argument means to move several steps in the cyclic order of windows. A negative argument moves around the cycle in the opposite order. When the minibuffer is active, the minibuffer is the last window in the cycle; you can switch from the minibuffer window to one of the other windows, and later switch back and finish supplying the minibuffer argument that is requested. *Note Minibuffer Edit::. The usual scrolling commands (*note Display::.) apply to the selected window only, but there is one command to scroll the next window. `C-M-v' (`scroll-other-window') scrolls the window that `C-x o' would select. It takes arguments, positive and negative, like `C-v'. (In the minibuffer, `C-M-v' scrolls the window that contains the minibuffer help display, if any, rather than the next window in the standard cyclic order.) The command `M-x compare-windows' lets you compare two files or buffers visible in two windows, by moving through them to the next mismatch. *Note Comparing Files::. File: emacs, Node: Pop Up Window, Next: Change Window, Prev: Other Window, Up: Windows Displaying in Another Window ============================ `C-x 4' is a prefix key for commands that select another window (splitting the window if there is only one) and select a buffer in that window. Different `C-x 4' commands have different ways of finding the buffer to select. `C-x 4 b BUFNAME RET' Select buffer BUFNAME in another window. This runs `switch-to-buffer-other-window'. `C-x 4 C-o BUFNAME RET' Display buffer BUFNAME in another window, but don't select that buffer or that window. This runs `display-buffer'. `C-x 4 f FILENAME RET' Visit file FILENAME and select its buffer in another window. This runs `find-file-other-window'. *Note Visiting::. `C-x 4 d DIRECTORY RET' Select a Dired buffer for directory DIRECTORY in another window. This runs `dired-other-window'. *Note Dired::. `C-x 4 m' Start composing a mail message in another window. This runs `mail-other-window'; its same-window analogue is `C-x m' (*note Sending Mail::.). `C-x 4 .' Find a tag in the current tag table in another window. This runs `find-tag-other-window', the multiple-window variant of `M-.' (*note Tags::.). `C-x 4 r FILENAME RET' Visit file FILENAME read-only, and select its buffer in another window. This runs `find-file-read-only-other-window'. *Note Visiting::. File: emacs, Node: Change Window, Prev: Pop Up Window, Up: Windows Deleting and Rearranging Windows ================================ `C-x 0' Get rid of the selected window (`delete-window'). That is a zero. `C-x 1' Get rid of all windows except the selected one (`delete-other-windows'). `C-x ^' Make selected window taller (`enlarge-window'). `C-x }' Make selected window wider (`enlarge-window-horizontally'). To delete a window, type `C-x 0' (`delete-window'). (That is a zero.) The space occupied by the deleted window is given to an adjacent window (but not the minibuffer window, even if that is active at the time). Once a window is deleted, its attributes are forgotten; only restoring a window configuration can bring it back. Deleting the window has no effect on the buffer it used to display; the buffer continues to exist, and you can select it in any window with `C-x b'. `C-x 1' (`delete-other-windows') is more powerful than `C-x 0'; it deletes all the windows except the selected one (and the minibuffer); the selected window expands to use the whole frame except for the echo area. To readjust the division of space among vertically adjacent windows, use `C-x ^' (`enlarge-window'). It makes the currently selected window get one line bigger, or as many lines as is specified with a numeric argument. With a negative argument, it makes the selected window smaller. `C-x }' (`enlarge-window-horizontally') makes the selected window wider by the specified number of columns. The extra screen space given to a window comes from one of its neighbors, if that is possible. If this makes any window too small, it is deleted and its space is given to an adjacent window. The minimum size is specified by the variables `window-min-height' and `window-min-width'. File: emacs, Node: Frames, Next: Major Modes, Prev: Windows, Up: Top Frames and X Windows ******************** When using the X Window System, you can create multiple windows at the X level in a single Emacs session. Each X window that belongs to Emacs displays a "frame" which can contain one or several Emacs windows. A frame initially contains a single general-purpose Emacs window which you can subdivide vertically or horizontally into smaller windows. A frame normally contains its own echo area and minibuffer, but you can make frames that don't have these--they use the echo area and minibuffer of another frame. Anything you do in one frame also affects the other frames. For instance, if you put text in the kill ring in one frame, you can yank it in another frame. If you exit emacs through `C-x C-c' in one frame, it terminates all the frames. To delete just one frame, use `C-x 5 0'. To avoid confusion, we reserve the word "window" for the subdivisions that Emacs implements, and never use it to refer to a frame. * Menu: * Mouse Commands:: Moving, cutting, and pasting, with the mouse. * Creating Frames:: Creating additional Emacs frames with various contents. * Frame Parameters:: Changing the colors and other modes of frames. * Scroll Bars:: How to enable and disable scroll bars; how to use them. * Menu Bars:: Enabling and disabling the menu bar. * Faces:: How to change the display style using faces. * Misc X:: Iconifying and deleting frames. Region highlighting. File: emacs, Node: Mouse Commands, Next: Creating Frames, Up: Frames Mouse Commands ============== `mouse-1' Move point to where you click (`mouse-set-point'). This is normally the left button. `drag-mouse-1' Move point to where you release the mouse, and set the mark where you initially clicked the mouse (`mouse-set-region'). Thus, you can specify both ends of the region. `mouse-2' Yank the last kill text, where you click (`mouse-yank-at-click'). This is normally the middle button. `mouse-3' Copy text to the kill ring (`mouse-save-then-click'). This is normally the right button. If you click it a second time at the same place, that kills the text. This operation applies to the text between point and the place where you click. Thus, to kill a section of text, you can press Mouse-1 at one end, then press Mouse-3 twice at the other end. To select the text for copying without deleting it from the buffer, press Mouse-3 just once. Then you can copy it elsewhere by yanking it. *Note Killing::. To yank the killed or copied text somewhere else, move the mouse there and press Mouse-2. *Note Yanking::. To copy text to another X window, kill it or save it in the kill ring. Under X, this also sets the "primary selection". Then use the "paste" or "yank" command of the program operating the other window to insert the text from the selection. To copy text from another X window, use the "cut" or "copy" command of the program operating the other window, to select the text you want. Then yank it in Emacs with `C-y' or Mouse-2. File: emacs, Node: Creating Frames, Next: Frame Parameters, Prev: Mouse Commands, Up: Frames Creating Frames =============== The prefix key `C-x 5' is analogous to `C-x 4', with parallel subcommands. The difference is that `C-x 5' commands create a new frame rather than just a new window in the selected frame. (*Note Pop Up Window::.) Different `C-x 4' commands have different ways of finding the buffer to select. `C-x 5 b BUFNAME RET' Select buffer BUFNAME in another window. This runs `switch-to-buffer-other-frame'. `C-x 5 f FILENAME RET' Visit file FILENAME and select its buffer in another frame. This runs `find-file-other-frame'. *Note Visiting::. `C-x 5 d DIRECTORY RET' Select a Dired buffer for directory DIRECTORY in another frame. This runs `dired-other-frame'. *Note Dired::. `C-x 5 m' Start composing a mail message in another frame. This runs `mail-other-frame', and its same-frame version is `C-x m'. *Note Sending Mail::. `C-x 5 .' Find a tag in the current tag table in another frame. This runs `find-tag-other-frame', the multiple-frame variant of `M-.'. *Note Tags::. `C-x 5 r FILENAME RET' Visit file FILENAME read-only, and select its buffer in another frame. This runs `find-file-read-only-other-frame'. *Note Visiting::. File: emacs, Node: Frame Parameters, Next: Scroll Bars, Prev: Creating Frames, Up: Frames Setting Frame Parameters ======================== This section describes commands for altering the display style and window management behavior of the selected frame. `M-x set-foreground-color RET COLOR RET' Specify color COLOR for the foreground of the selected frame. `M-x set-background-color RET COLOR RET' Specify color COLOR for the background of the selected frame. `M-x set-cursor-color RET COLOR RET' Specify color COLOR for the cursor of the selected frame. `M-x set-mouse-color RET COLOR RET' Specify color COLOR for the mouse cursor when it is over the selected frame. `M-x set-border-color RET COLOR RET' Specify color COLOR for the border of the selected frame. `M-x auto-raise-mode' Toggle whether or not the selected frame should auto-raise. Auto-raise means that every time you move the mouse onto the frame, it raises the frame. `M-x auto-lower-mode' Toggle whether or not the selected frame should auto-lower. Auto-lower means that every time you move the mouse off of the frame, the frame moves to the bottom of the stack of X windows. `M-x set-default-font RET FONT RET' Specify font FONT as the default for the selected frame. *Note Font X::, for ways to list the available fonts on your system. You can also set a frame's default font through a pop-up menu. Press `C-Mouse-3' to activate this menu. File: emacs, Node: Scroll Bars, Next: Menu Bars, Prev: Frame Parameters, Up: Frames Scroll Bars =========== When using X, Emacs normally makes a "scroll bar" at the right of each Emacs window. The scroll bar runs the height of the window, and shows a moving rectangular inner box which represents the portion of the buffer currently displayed. The entire height of the scroll bar represents the entire length of the buffer. You can use Mouse-2 (normally, the middle button) in the scroll bar to move or drag the inner box up and down. If you move it to the top of the scroll bar, you see the top of the buffer. If you move it to the bottom of the scroll bar, you see the bottom of the buffer. The left and right buttons in the scroll bar scroll by controlled increments. Mouse-1 (normally, the left button) moves the line at the level where you click up to the top of the window. Mouse-3 (normally, the right button) moves the line at the top of the window down to the level where you click. By clicking repeatedly in the same place, you can scroll by the same distance over and over. You can enable or disable Scroll Bar mode with the command `M-x scroll-bar-mode'. With no argument, it toggles the use of scroll bars. With an argument, it turns use of scroll bars on if and only if the argument is positive. This command applies to all frames, including frames yet to be created. To enable or disable scroll bars for just the selected frame, use the `M-x toggle-scroll-bar' command.