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UPDATE.DOC, ARJ 2.55b ALPHA TEST July 1996
This documents new or updated information since ARJ 2.50.
** IMPORTANT NEWS ****************************************************
*** THIS VERSION OF ARJ IS THE SECOND PUBLIC ALPHA TEST RELEASE.
*** A few bugs have been fixed. See WHATSNEW.DOC for details.
This is a test release with new features which may be changed in
the final release. The purpose of this release is to gather
comment on the design of the new features and to find program
bugs. We welcome any suggestions or bug reports that you might
have to improve upon this version of ARJ.
The most likely areas of bugs involve handling filenames longer
than 80 characters and using XMS memory to handle a large number
of filenames.
DO NOT USE THIS TEST VERSION OF ARJ AFTER DECEMBER 1996. Look
for an official release of ARJ then. There is NO expiration
timer in this program. The time limit is for your protection and
is strictly voluntary. You should not use a test version of any
software for too long.
The mailing address of ARJ Software has changed as of August 1993.
ARJ Software
Robert and Susan Jung
P.O. Box 249
Norwood MA 02062
USA
FAX: 617-769-4893
EMAIL: robjung@world.std.com
There is ARJ Internet mailing list and WEB site support
information added to the file ARJ.DOC.
---------
This version of ARJ will use more conventional memory than
previous versions of ARJ. However, using the "-hm1" or "-hm!"
option will reduce your memory requirements especially when
archiving a large number of files.
---------
After ARJ version 2.41a, full functionality of certain ARJ
software features will NOT be available in the shareware
versions of ARJ (registered or not). These features include the
multiple volume self-extractor, the ARJSFX embedded command line
feature, and the inhibit display messages option. The full
featured versions will ONLY be available from ARJ Software and
its agents. Registered ARJ users can upgrade to this version
for a small shipping/handling fee ($5) or a SASE with diskette.
For credit card users, the upgrade fee will be $10 because of
minimum fee charge requirements.
Check the WHATSNEW.DOC file for changes since ARJ 2.41a.
---------
** THIS VERSION OF ARJ HAS LONG FILENAME SUPPORT UNDER WINDOWS 95.
---------
This version now supports ARJ-SECURITY for multiple volume
archives and multiple volume self-extractors.
---------
New to this version of ARJ is a data damage protection option.
A slightly damaged/corrupted ARJ file can be repaired if the
archive was protected by creating a data protection file before
the damage occurred. See below for more information.
---------
New to this version of ARJ is the concept of backup CHAPTERS.
This allows the user to do MULTIPLE full backups to a SINGLE
archive in such a manner as to allow the full restoration of the
files at the time of ANY of the backups (CHAPTERS). This allows
the user to backtrack easily, a feature valuable to software
developers. Deleted files are also accounted for in this
chapter scheme.
To go along with the new CHAPTER feature, ARJ now fully supports
the UPDATE of multiple volume archives. To implement this
feature reliably in multiple volumes, all new or changed files
are added at the END of the LAST volume. This re-arrangement
only occurs with multiple volume archives. This prevents the
diskette overflow that would occur with earlier versions of ARJ.
Because of the new CHAPTER feature, ARJ NO LONGER SUPPORTS the
old ARJ backup file feature. This is the old "-jb / -jg"
functionality. This version of ARJ will not process this type
of archive properly.
See the "ac" command and "-jb" option for more information about
CHAPTER archives.
---------
New to this version is the "hollow" archive. This is an ARJ
archive that does NOT contain the compressed file data. The
main application for this kind of archive is scanning for
CHANGED files. This makes the hollow archive useful for file
integrity scanning as in virus damage scanning.
---------
This version of ARJ provides a new encryption scheme based upon
the Russian encryption algorithm (GOST 28147-89 cipher). This
algorithm is similar in design to DES; however, GOST is designed
for software implementation. This implementation uses the 64
bit cipher feedback mode.
This new encryption is accessed by using the "-g" option to
specify the password and the "-hg" option to specify the new
scheme. This new scheme is in addition to the older XOR garble
scheme.
** Please NOTE that losing your password means losing your file!
** Please do NOT ask for technical support on lost passwords.
** There is no shortcut/backdoor for determining lost passwords.
The encryption module is a separate COM file named ARJCRYPT.COM.
ARJ expects to find the encryption module in the same directory
as itself. ARJ treats the COM file as an overlay type module.
This has the advantage of saving space with the ARJSFXV module
and the DEARJ.EXE module when encryption is not needed. You
simply do not include the encryption module in the archive.
For non-USA users, the encryption overlay module is not included
with this version of ARJ. Because of USA export regulations,
the encryption overlay module may not be exported from the USA.
---------
ARJ can archive up to 32,000 files at one time when the "-hm"
option is specified. This option enables ARJ to use disk space
instead of memory space to manage the names of the files being
archived. The "-hm!" option uses XMS memory to manage the list
of names. At this revision of ARJ, checking for duplicates is
NOT disabled as it was in 2.50.
---------
The multiple volume SELF-EXTRACTION FUNCTION is LIMITED in the
ARJ shareware version. Only volumes of 360K or less in size can
be created AND only such volumes will be processed by the
self-extractor. This feature is accessed through the "-je"
option along with the "-v" option.
This multiple volume self-extractor supports ANSI escape
sequence displays. It also supports ARJ-SECURE over multiple
volumes and the new encryption method.
---------
The extraction "-jo" option now works in cooperation with the
"-f" and "-u" type options. Previously, the "-jo" option
disabled the "-f" and "-u" options.
---------
The "-g" option will NOW force compression even when a size
increase results except when the "-m0" option is used.
Encrypted compressed data is more secure than encrypted stored
(-m0) data.
---------
This version no longer detects the older 2.30 ARJ-SECURE
archives.
---------
** CAUTIONS **
Whenever archiving to diskettes, it is HIGHLY recommended that
the option "-jt" be used. This helps spot BAD diskettes or BAD
diskette drives. It is HIGHLY recommended that the "-jt" option
be used in a Windows or multi-tasking or network environment.
UNERASE or UNDELETE commands do not always recover a file
correctly. This will result in damaged archives. This is true
for all archive types. You should always test an archive after
unerasing it.
CAUTION: To those who use the "-t1" and/or "-t1g" options to
save a few extra bytes. This option should only be used on TEXT
FILES. Those are files created by EDLIN, EDIT, QEDIT, BRIEF,
NOTEPAD, and others. Text files typically contain only letters,
numbers, spaces, and punctuation marks. WORD PROCESSOR format
files ARE NOT TEXT FILES! MS WORD, Wordperfect, AMIPRO, WRITE,
and similar files ARE NOT TEXT FILES. Using the "-t1" or "-t1g"
on any other kind of file probably will result in DATA LOSS!
**********************************************************************
WINDOWS 95 LONG FILENAME SUPPORT
This version of ARJ supports the use of long filenames under the
Windows 95 in the MS-DOS Prompt environment. It does not support
long filenames under MS-DOS 6.22 and below. It supports long
filenames ONLY when the Windows 95 GUI (graphical user interface)
is running. In other words, there is no long filename support in
Windows 95 MS-DOS mode (accessed from the Win95 shutdown menu).
The small ARJ self-extractor (-je1) does NOT support the handling
of long filenames.
The ARJSFX and ARJSFXV modules (-je) support long filename
handling. However, they will only extract archived Win95 long
filename files under Win95. If long filename files are being
extracted to plain DOS, an error message will be displayed. They
can be forced to extract the Win95 archived files with the "-j"
option.
For compatibility with MS-DOS and older versions of ARJ, ARJ can
create a dual-name compatibility ARJ archive. This is an archive
with both shortnames and longnames stored in it. The longnames are
stored in the file comment field. New versions of ARJ will treat
the dual-name archive according to the operating system
environment. In other words, under MS-DOS, a dual-name archive
will look like a shortname archive. Under WIN95, a dual-name
archive will look like a longname archive. This is also true of
the ARJSFX and ARJSFXV modules (-je).
For efficiency reasons ARJ does not repeatedly check for file
system support of long filenames. ARJ only tests the "C:" file
system. An error may occur if ARJ under Win95 tries to access a
disk drive that does not support long filename handling. The "-hf"
option can be used to force ARJ to use the standard 8.3 filename
APIs instead of the longname APIs.
There are three new options "-hf", "-hf1", and "-hf2" that provide
choices in the handling of long filenames. See the discussion of
those options below for more information.
ARJ will save Win95 long filenames in the letter case they are
stored on disk; however, all filename matching is done without
regard to case. In other words, "ThisName.Ext" matches
"thisNAME.ext".
When archiving files under Windows 95, be sure to EXCLUDE files
from processing that are OPEN such as WIN386.SWP.
ARJ RESPONSE FILE PROCESSING:
ARJ will accept an ARJ command line from a response file as in
"ARJ @command.rsp". The "@" symbol indicates that the appended
name is the name of the response file. In this case, the file is
command.rsp. The response file symbol cannot be changed.
The response file should contain the ARJ command line minus the
initial "ARJ". The command line may be split over as many lines
as necessary. The response file feature will NOT accept QUOTED
command line options. Options with embedded blanks ("-vasTEST X")
will not be processed as expected. See the "-@" option for
help on options with blanks. When using the response file feature,
ARJ will accept only the "-+", and "-&" switch options on the DOS
command line along with the response file name. All other command
options must be specified in the response file or in the ARJ
environment variable.
To better support long filenames, ARJ provides the "-@" option to
handle the processing of filenames and switch options that contain
embedded spaces. The "-@" switch option enables the interpretation
of a text line in an ARJ response file as a single token. In other
words, when ARJ scans an "-@" option, it will process the NEXT text
line in the response file as a single token including all embedded,
leading, and trailing blanks. ARJ will continue to process each
subsequent text line in the same manner. If ARJ scans a subsequent
"-@" option, ARJ will revert to its normal multiple tokens per line
processing.
ARJ-PROTECT DATA PROTECTION FEATURE
With this version, ARJ can repair "protected" archives that suffer
from slight amounts of data damage (CRC error, bad header, etc). An
ARJ archive is "protected" with the "-hk" option. With the "-hk"
option, ARJ will generate a separate ARJ data protection file. This
protection file is REQUIRED in order to repair damaged ARJ
archives. The size of this file ranges from a minimum of 4096
bytes and upwards. For larger archives, the protection file size
is typically less than one percent of the archive file size.
For this release, the protection file is a separate file. This
avoids the problem of uploading unnecessary data to BBSes and ftp
sites. The name of the protection file is based upon the archive
name plus the extension ".XRJ". Volume protection files end in
".X01", etc.
This protection feature is sector based and allows repair due to
typical types of disk corruption (bad sector, virus damage, cross
links, etc). This type of sector protection is NOT effective for
most data transmission problems where data is missing from the
middle of a transmission.
Technically, this protection feature uses a series of XOR sums and
checksums in order to allow repairs. Larger archives are logically
treated as separate streams of data. ARJ can protect each "stream"
from one or two damaged sections 1024 bytes in size. However, for
large archives (1 MB or larger) ARJ can sometimes repair up to four
damaged sections per MByte. The "-hk1, "-hk2" ... "-hk9" options
can offer more data protection at the cost of a proportionately
larger protection file.
The "-hk" option sets ARJ to build a protection file. The "q"
command is used to repair a damaged archive. The repaired archive
is named ARJFIXED.ARJ.
Example: ARJ a archive -hk generates archive.xrj
ARJ q archive repairs archive.arj
ARJ ANSI COMMENT HANDLING
At version 2.55, ARJ will use its own ANSI sequence display handler
to display ARJ comments. In previous versions, ARJ depended upon
the "-ja" option and an installed ANSI.SYS driver to handle the
ANSI escape sequences. The "-ja" option has a new function now.
The "-ja" option will set the "P" command to display files using
the new ANSI sequence display handler.
The ARJSFXV module (-je -v) also will display ANSI comments now.
Please note that the ARJ comment field size is limited to about 2K
bytes.
ARJSFXV MULTIPLE VOLUME SELF-EXTRACTOR
This module now supports ARJ-SECURE and ANSI escape sequences in
the archive comment. You can build a single volume
self-extracting archive by specifying a larger volume size. The
ARJ distribution archive uses the ARJSFXV module because of the
ANSI comment support.
Example: ARJ a archive *.* -je -v300K
ARJ COMMANDS
"ac" command
This is a new two character command for ARJ. It is actually an
abbreviation for the following command and switch options:
"u -u2 -jb". The "ac" command will add a chapter backup to a new
archive or add a new chapter (updating) to a chapter archive.
Example: ARJ ac archive c:\dir\*.* -r -jt
The advantage of a chapter archive is that you can make numerous
full backups (chapters) to a SINGLE archive. Major space savings
will result when some files do not change from backup to backup.
See the "-jb" option for more details.
"e" command
"x" command
Chapter archives do NOT support extraction with deletion.
ARJ x archive *.doc -d generates "Bad command syntax"
"q" command
The "q" command is used to repair a damaged "protected" archive.
An archive is protected with the "-hk" option. Both the protected
archive and its ARJ-PROTECT data protection file are required to
repair any damage. The "q" command will attempt to repair all
damages and put the repaired archive in a file named ARJFIXED.ARJ.
Example: ARJ q archive
When working with a damaged archive and the "Abort, Retry, Ignore,
Fail" prompt appears, you should select the "Ignore" option.
"y" command
When used with the "-g" option and optionally the "-hg" option,
ARJ will ungarble a previously garbled archive.
Example: ARJ y archive -gpasswrd
When used with the "-jb" option, ARJ will convert a standard
archive to a chapter archive.
Example: ARJ y archive -jb
When used with the "-jb*" option, ARJ will convert a chapter
archive to a standard archive.
Example: ARJ y archive -jb*
ARJ SWITCHES
"-@" switch
This switch sets ARJ to enable/disable the interpretation of text
lines in an ARJ RESPONSE file as a complete single token. Normally,
in an ARJ response file, blanks are interpreted as token
separators. (Tokens are commands, filenames, wildcards, and switch
options). However, if ARJ scans an "-@" option in a response file,
it will process subsequent text lines as single tokens per line. A
subsequent "-@" option will revert ARJ to normal multiple tokens
per line mode.
Example: ARJ @text.rsp
TEXT.RSP contains:
a c:\dir\archive -r -jt1 -@ -a1
c:\long directory name\*.*
c:\other directory name\*.*
-@
dir1\*.* dir2\*.* dir3\*.*
One common error when using the "-@" option is including extraneous
leading and/or trailing blanks. For example, ARJ will abort with
an invalid switch option error if the second "-@" above has one or
more trailing blanks.
"-b" switch
Under Windows 95, the use of the "-b" type switch options to reset
the archive bit may result in a sharing violation error. Under
ARJ 2.55b, ARJ will display the error and then proceed ignoring
the error.
"-e" switch
This switch used during extraction will exclude the beginning
characters of the filename. This can be useful for shortening a
long output pathname.
Examples: ARJ x archive -e10 will exclude the first 10
characters of the output filename.
ARJ x archive -e4 will exclude the first 4 characters.
"-f1" switch
This switch is used to select files that are OLDER for extracting
or adding.
"-f2" switch
This switch is used to select files that are DIFFERENT (different
date-time or different size) for extracting or adding.
There is a slight limitation to this switch. When processing
files that are split across volumes, the size test is skipped.
"-g" switch
The garble option in this version of ARJ has two versions. One
is the original version found in earlier ARJ releases. It is
compatible with older versions and works like those versions.
The other garble version uses a separate encryption module. ARJ
treats this module as an overlay.
This new option is accessed by using the new "-hg" option. This
option sets ARJ to use the separate encryption module to encrypt
the data. By default, ARJ will look for the file "ARJCRYPT.COM"
in the same directory where the ARJ.EXE being executed is found.
The user may specify the pathname of the module to use.
Examples: ARJ a archive *.doc -gThis_is_a_password -hg
ARJ a archive *.doc -gpassword -hgc:\dir\enc.com
The new garble option accepts a password key up to 32 characters
long. Excess characters are ignored. Garble passwords ARE CASE
SENSITIVE! DO NOT LOSE your password! There is no known method to
recover the password other than by brute force, which could take a
very long time. The longer the password, the longer it would take
to "guess" it.
This new encryption scheme is not compatible with the "-g" option
of pre-2.55 versions of ARJ. If you want to maintain compatibility
with pre-2.55 versions of ARJ, you should NOT use the "-hg" option.
Only the multiple volume self-extractor supports the new encryption
module.
When garbling or ungarbling an existing archive, ARJ will detect
the method of encryption previously used and select that same
method even if the "-hg" option was not specified.
"-s3" switch
This switch sets ARJ to keep both the original archive file
time-stamp as well as the original internal archive modified
time-stamp when modifying the archive.
This feature is helpful when adding a copy of the data damage
protection file to the "protected" archive. Using this switch,
you can add a file to an archive and then remove that file and
end up with the original archive. This is necessary because any
change in archive contents would be perceived as damage by the
ARJ "q" (repair archive) command.
Example: ARJ a archive *.doc -hk
ARJ a archive archive.xrj -s3
ARJ e archive archive.xrj -d -s3
ARJ q archive
The above sequence of commands replicates a situation where the
user embeds a copy of the data damage protection file into the
"protected" archive. In the case of slight archive damage, the
protection file can be extracted and used to recover damaged data.
"-u1" switch
This switch is used to select files that are OLDER or NEW for
extracting or adding.
"-u2" switch
This switch is used to select files that are DIFFERENT (different
date-time or different size) or NEW for extracting or adding.
There is a slight limitation to this switch. When processing
files that are split across volumes, the size test is skipped.
"-v" switch
For specifying sizes for this option, ARJ will accept the "M"
modifier to multiply by 1,000,000 (one million).
Examples: ARJ a vol -v100M
ARJ a vol -vr1M1440
"-hf" switch
This switch disables Windows 95 long filename handling. ARJ will
use the standard DOS 8.3 APIs to do its processing. Files so
archived with this switch can be extracted under Windows 95 and
DOS.
This switch can be used while listing a dual-name archive under
Win95 to list/process the shortnames.
"-hf1" switch
This switch in Win95 during archival sets ARJ to build a dual-name
compatibility archive by storing the shortname in the filename
field and the longname in the file comment field, so that both long
filenames and short filenames are stored in the archive.
Such a dual-name archive is compatible with older versions of ARJ.
New versions of ARJ process such an archive according to the
current operating system environment. Under Win95, the long
filenames in the archive are used. Under MS-DOS, the short
filenames are used. This processing is automatic for this release
of ARJ.
The "-e1" option does not affect the short name that is stored.
This switch during extraction in an environment where long
filenames are not supported sets ARJ to extract files using
generated names. ARJ will generate a short name based upon
"W95LNAME.000" and its sequence number in the archive.
"-hf2" switch
This switch sets ARJ to attempt to extract using the long filenames
stored in the archive. No modification is done to the long
filenames except by DOS itself. This switch also sets ARJ to use
the standard DOS 8.3 APIs for processing. Because of the
shortening of the filenames by DOS, duplicate filenames may result.
"-hg" switch
This switch is used to specify the filename of the encryption
module to be used when encrypting a new archive. The default
filename is "ARJCRYPT.COM". ARJCRYPT.COM contains a new encryption
scheme that is incompatible with earlier releases of ARJ. ARJ will
look for the encryption module in the directory that contains the
copy ARJ.EXE that is being executed unless the specified module
name contains a path symbol "\" as in "ARJ\OLDCRYPT.COM". If you
want to use a module in the current directory, you should specify
the name as in ".\ARJCRYPT.COM". The "." indicates the current
directory.
With an existing archive, ARJ detects the encryption scheme that
was used to encrypt the archive and uses the same scheme regardless
of whether the "-hg" option is specified or not.
"-hk" switch
The "-hk" switch sets ARJ to create an ARJ-PROTECT data protection
file. This file is named similarly to the created archive except
for an "X" in the beginning of the file extension as in NAME.XRJ.
This ARJ-PROTECT file contains necessary information to repair
damage to the original archive. The "-hk1", "-hk2" ... "-hk9"
options will generate larger ARJ-PROTECT files affording a higher
probability of a successful repair.
For users who do not like the separate protection file feature,
there is a work-around. Using the new "-s3" option (keep original
time-stamps), the user can add the ARJ-PROTECT file to the
protected archive and extract it later for repair purposes.
Example: ARJ a docs *.txt -hk builds protected archive
ARJ a docs docs.xrj -s3 inserts protect file
ARJ e docs docs.xrj -s3 -d extracts and removes
protect file restoring
the original archive
ARJ q docs repairs archive
"-hm" switch
The "-hm" switch sets ARJ to transfer the list of filenames to be
archived from the limited conventional memory to file storage.
This allows a much larger number of files to be processed (over
32,000). This option is ignored for all ARJ commands except
"a", "f", "j", "m", "u".
Normally, this switch sets ARJ to wait until it is out of memory
storing filenames into a list before transferring that list to a
temporary file. That temporary file is put in the current
directory or the special work directory if specified (-hm!F:\) or
XMS memory is specified (-hm!).
However, there may be a few cases where ARJ will run out of memory
doing other tasks while it is storing this list. In these cases,
ARJ will abort. The user can specify a numeric argument of "1" to
this switch to force ARJ to transfer the list to file storage
immediately.
The "-hm" work directory is specified by appending a "!" to the
"-hm" or "-hm1" options and then appending the filename to the
option. See below.
Examples: ARJ a archive c:\*.* -r -hm
ARJ a archive c:\*.* -r -hm1
ARJ a a:archive c:\*.* -r -va -hm500!F:\
ARJ a a:archive c:\*.* -r -hm!G:\temp\
The use of a RAMDISK directory will provide the fastest operation.
"-hm!" switch
The "-hm!" option with no pathname appended to it will set ARJ to
store its list of filenames in XMS memory. List processing will be
faster using XMS memory as opposed to using disk space. If no XMS
memory is available, ARJ will use conventional memory and then disk
space if needed.
If there is not enough XMS memory for available for the internal
list, ARJ will abort.
"-j#" switch
This switch allows the building and testing of a special ARJ
"HOLLOW" archive that is missing the actual compressed file
contents. This allows the creation of small archives for CRC
testing against the CRCs of actual files. This is suited for
special applications. Please take note that NO actual file data can
be extracted from these "HOLLOW" archives.
For example, a user has transported a directory of files from one
PC to another PC. At a later time, that user would like to
determine which files have actually changed their contents
regardless of the date-time stamps. That user could archive the
original directory using the -j# switch which builds the ARJ
"hollow" archive with the sole exception that no compressed data is
stored with the archive. This allows the rapid building of a much
smaller archive. The file CRC is computed and stored in the
archive. This new "hollow" archive is transported to the other PC.
A simple ARJ test command with the "-jt1" option on the other PC
would point out files whose content's CRC do not match.
Another use of this "hollow" archive is for FILE INTEGRITY
checking. You can create this "hollow" CRC archive and use it at a
later time to determine if any files have been corrupted or damaged
by VIRUS or system problems.
Please note that there is a VERY SMALL possibility that a file has
been changed and its new 32 bit CRC still matches. That
possibility is approximately one in four billion.
The -j# option during an ARJ archive build will set the compression
method to 9. The only change is that the file header will indicate
that the compressed file size is ZERO. Otherwise, the file header
is the same as in an archive where the file was actually compressed
and stored.
To use this "hollow" archive to test CRCs against actual file CRCs,
use the following syntax:
Syntax: ARJ t archive_name -jt1
ARJ t archive_name target_dir\ -jt1
The second command above is used where the relative pathnames
stored in the archive do not match up with the current directory.
See the discussion in ARJ.DOC for more information on the option
"-jt".
When ARJ displays "NOT matched" for a "hollow" archive, it means
the file size in the archive and the size of the actual file do NOT
match.
"-ja" switch
This switch has acquired NEW functionality. Its OLD function was
to set ARJ to fully display ANSI escape sequences. It now is used
with the "ARJ p" command to display files using ARJ's own ANSI
display handler. ANSI.SYS is no longer needed.
Example: ARJ p ansifile -ja -q
"-jb" switch
This switch sets ARJ to build a chapter archive. Once an archive
is set to a chapter archive, all subsequent processing will
continue to treat it as a chapter archive.
The advantage of a chapter archive over a series of separate
archives of the same set of files is that space can be saved when
archived files do not change. A single chapter archive can produce
the same results as one hundred standard archive backups. In other
words, one can update a chapter archive one hundred times and fully
recover any one of those updates.
Technically speaking, each file in a chapter archive has a chapter
lifespan range. When a file is backed up and has not changed since
the last backup, only the lifespan range is changed. A copy of the
file is NOT added to the archive since a copy already exists in the
archive. If the backed up file is different from the previous
version, then that file is added to the archive with an appropriate
chapter range. The previous version of the file is still kept in
the chapter archive. When a particular chapter is restored, ARJ
selects only the files whose lifespan includes the chapter number
requested.
As an example, suppose one made a series of daily chapter backups
of a document directory where only one document out of the one
hundred documents changes on a daily basis. The chapter archive
would contain the original one hundred documents plus a copy of
each day's changed document.
When processing chapter archives, all ARJ add type commands
(A,M,F,U) will create a new chapter in the chapter archive. Up to
a maximum of 250 chapters can be stored in a single archive. The
proper way to build and update a chapter archive is with the "ac"
command. You should use the same command line arguments for
each chapter update. If you fail to select the same files as
before, the chapter archive will not update the lifespan ranges
properly and those unselected files will "appear" to have been
deleted for the current chapter. By default, the "ac" command
will update a chapter archive with files that are DIFFERENT from
the previous chapter (different size or date-time stamp). The
"ac" command is actually an abbreviation for the following
command and options: "u -u2 -jb", so you CANNOT use the "-u" or
"-jb" options with the "ac" command.
ARJ ac archive dir\ *.txt *.doc *.wri initial build
ARJ ac archive dir\ *.txt *.doc *.wri second chapter
ARJ ac archive dir\ *.txt *.doc *.wri third chapter
ARJ ac archive dir\ *.txt *.doc *.wri fourth chapter
ARJ ac archive dir\ *.txt *.doc fifth chapter will
be missing all *.wri files
An expert with ARJ may want to use the actual commands and switches
instead of the "ac" command.
ARJ u -u2 -jb archive dir\ *.txt
The "-jb$" option will allow ARJ add type commands to update/replace
files in the most recent chapter in the archive. This option can be
used to "fix" a chapter where files are missing. Be careful doing
this. It is much simpler and safer to add a new chapter to the
archive.
ARJ a archive -jb$ dir\ *.wri
It is possible to change a standard ARJ archive to a chapter archive
with the "y" command and the "-jb" option. The opposite is possible
with the "-jb*" option.
ARJ y archive -jb converts archive to chapter archive
ARJ y archive -jb* converts chapter archive to standard archive
You can restore the files in the most recent chapter as in:
ARJ x archive
You can restore a specific chapter as in:
ARJ x archive -jb10 restores chapter 10
ARJ x archive -jb20 restores chapter 20
You can list a specific chapter as in:
ARJ l archive -jb10 lists chapter 10
ARJ l archive lists the most recent chapter
You can see the chapter ranges for each file in the archive with
the following command:
ARJ l archive -jb* -jv
To start all over again with a chapter archive, you should purge all
of the previous chapters, convert the archive to a standard archive,
and then back to an archive chapter.
You cannot modify specific chapters other than the most recent
chapter.
You can remove the most recent chapter with the following command:
ARJ d archive *.* -jb
If you do not specify the "-jb" with a delete command, the archive
chapter header will not be deleted.
"-jb*" switch
This switch is used to select all chapters.
When it is used with the LIST command, ARJ displays all chapters.
ARJ l archive -jb* displays all chapters
This switch can be used with the DELETE command to remove all
chapters of selected file(s).
ARJ d archive -jb* *.bak *.tmp
This switch is also used with the "y" command to convert a standard
archive to a chapter archive.
ARJ y archive -jb* converts chapter archive to standard archive
"-jb$" switch
This switch can be used with the ADD command to modify the most
recent chapter files.
ARJ a archive -jb$ dir\ *.wri
This switch can be used with the DELETE command to purge all BUT
the current chapter.
ARJ d archive -jb$ *.* is the same as ARJ k archive *.*
"-jo" switch
New to this release, the "-jo" option during extraction works along
with the "-f" and "-u" type options. In other words, if you want to
freshen a set of files from an archive, the use of the "-jo" option
will generate unique names for any files extracted.
Example: ARJ x archive *.* -u -jo
"-jyv" switch
As a clarification of older documentation, the "-jyv" option will
disable the next volume prompt EVEN with removable media. The
global "-y" option does not disable the next volume prompt with
removable media.
end document