@end itemize
Some of these aims are already attained, while others are still
-being worked upon. From the point of view of an end user, the
+being worked upon. From the point of view of an end user, the
following issues need special mentioning:
@table @asis
option as a synonym for @option{--old-archive}.
@GNUTAR{} starting from version 1.13.90 understands this option as
-a synonym for @option{--no-same-owner}. This is compatible with
+a synonym for @option{--no-same-owner}. This is compatible with
UNIX98 @command{tar} implementations.
However, to facilitate transition, @option{-o} option retains its
It is especially important, since versions of @acronym{GNU} Automake
up to and including 1.8.4 invoke tar with this option to produce
-distribution tarballs. @xref{Formats,v7}, for the detailed discussion
+distribution tarballs. @xref{Formats,v7}, for the detailed discussion
of this issue and its implications.
Future versions of @GNUTAR{} will understand @option{-o} only as a
@item Use of short option @option{-l}
Earlier versions of @GNUTAR{} understood @option{-l} option as a
-synonym for @option{--one-file-system}. Such usage is deprecated.
+synonym for @option{--one-file-system}. Such usage is deprecated.
For compatibility with other implementations future versions of
@GNUTAR{} will understand this option as a synonym for
@option{--check-links}.
@item Use of options @option{--portability} and @option{--old-archive}
-These options are deprecated. Please use @option{--format=v7} instead.
+These options are deprecated. Please use @option{--format=v7} instead.
@item Use of option @option{--posix}
-This option is deprecated. Please use @option{--format=posix} instead.
+This option is deprecated. Please use @option{--format=posix} instead.
@end table
@node Authors
In July, 2003 @GNUTAR{} was put on CVS at savannah.gnu.org
(see @url{http://savannah.gnu.org/projects/tar}), and
active development and maintenance work has started
-again. Currently @GNUTAR{} is being maintained by Paul Eggert, Sergey
+again. Currently @GNUTAR{} is being maintained by Paul Eggert, Sergey
Poznyakoff and Jeff Bailey.
Support for @acronym{POSIX} archives was added by Sergey Poznyakoff.
please report them to @file{bug-tar@@gnu.org}.
When reporting a bug, please be sure to include as much detail as
-possible, in order to reproduce it. @FIXME{Be more specific, I'd
+possible, in order to reproduce it. @FIXME{Be more specific, I'd
like to make this node as detailed as 'Bug reporting' node in Emacs
manual}.
Sometimes, a single instance of @option{--verbose} on the command line
will show a full, @samp{ls} style listing of an archive or files,
giving sizes, owners, and similar information. @FIXME{Describe the
-exact output format, e.g., how hard links are displayed.}
+exact output format, e.g., how hard links are displayed.}
Other times, @option{--verbose} will only show files or members that the particular
operation is operating on at the time. In the latter case, you can
use @option{--verbose} twice in a command to get a listing such as that
@noindent
This will put you into the directory which contains @file{practice},
-i.e. your home directory. Once in the superior directory, you can
+i.e., your home directory. Once in the superior directory, you can
specify the subdirectory, @file{practice}, as a file name argument. To
store @file{practice} in the new archive file @file{music.tar}, type:
@anchor{listing member and file names}
It is important to notice that the output of @kbd{tar --list
--verbose} does not necessarily match that produced by @kbd{tar
---create --verbose} while creating the archive. It is because
+--create --verbose} while creating the archive. It is because
@GNUTAR{}, unless told explicitly not to do so, removes some directory
prefixes from file names before storing them in the archive
-(@xref{absolute}, for more information). In other
+(@xref{absolute}, for more information). In other
words, in verbose mode @GNUTAR{} shows @dfn{file names} when creating
-an archive and @dfn{member names} when listing it. Consider this
+an archive and @dfn{member names} when listing it. Consider this
example:
@smallexample
@end smallexample
@cindex @option{--show-stored-names} described
- This default behavior can sometimes be inconvenient. You can force
+ This default behavior can sometimes be inconvenient. You can force
@GNUTAR{} show member names when creating archive by supplying
@option{--show-stored-names} option.
earlier (say, @file{blues}), you can extract it from the archive without
changing the archive's structure. It will be identical to the original
file @file{blues} that you deleted. @FIXME{At the time of this
-writing, atime and ctime are not restored. Since this is a tutorial
-for a beginnig user, it should hardly be mentioned here. Maybe in
-a footnote? --gray}.
+writing, atime and ctime are not restored. Since this is a tutorial
+for a beginnig user, it should hardly be mentioned here. Maybe in
+a footnote? --gray}.
First, make sure you are in the @file{practice} directory, and list the
files in the directory. Now, delete the file, @samp{blues}, and list
styles.
@FIXME{menu at end of this node. need to think of an actual outline
-for this chapter; probably do that after stuff from chap. 4 is
+for this chapter; probably do that after stuff from chapter 4 is
incorporated.}
@node Styles
only use the option style(s) which makes the most sense to you until you
feel comfortable with the others.
-Some options @emph{may} take an argument (currently, there are
-two such options: @value{op-backup} and @value{op-occurrence}). Such
+Some options @emph{may} take an argument (currently, there are
+two such options: @value{op-backup} and @value{op-occurrence}). Such
options may have at most long and short forms, they do not have old style
-equivalent. The rules for specifying an argument for such options
-are stricter than those for specifying mandatory arguments. Please,
+equivalent. The rules for specifying an argument for such options
+are stricter than those for specifying mandatory arguments. Please,
pay special attention to them.
@menu
"mnemonic" with "long", or *ugh* vice versa.}
Each option has at least one long (or mnemonic) name starting with two
-dashes in a row, e.g.@: @option{--list}. The long names are more clear than
+dashes in a row, e.g., @option{--list}. The long names are more clear than
their corresponding short or old names. It sometimes happens that a
single mnemonic option has many different different names which are
synonymous, such as @option{--compare} and @option{--diff}. In addition,
for those not fully acquainted with @command{tar}.
Mnemonic options which require arguments take those arguments
-immediately following the option name. There are two ways of
-specifying a mandatory argument. It can be separated from the
+immediately following the option name. There are two ways of
+specifying a mandatory argument. It can be separated from the
option name either by an equal sign, or by any amount of
-white space characters. For example, the @option{--file} option (which
+white space characters. For example, the @option{--file} option (which
tells the name of the @command{tar} archive) is given a file such as
@file{archive.tar} as argument by using any of the following notations:
@option{--file=archive.tar} or @option{--file archive.tar}.
In contrast, optional arguments must always be introduced using
-an equal sign. For example, the @option{--backup} option takes
-an optional argument specifying backup type. It must be used
+an equal sign. For example, the @option{--backup} option takes
+an optional argument specifying backup type. It must be used
as @option{--backup=@var{backup-type}}.
@node Short Options
@subsection Short Option Style
Most options also have a short option name. Short options start with
-a single dash, and are followed by a single character, e.g.@: @option{-t}
+a single dash, and are followed by a single character, e.g., @option{-t}
(which is equivalent to @option{--list}). The forms are absolutely
identical in function; they are interchangeable.
Short options' letters may be clumped together, but you are not
required to do this (as compared to old options; see below). When
short options are clumped as a set, use one (single) dash for them
-all, e.g.@: @w{@samp{@command{tar} -cvf}}. Only the last option in
+all, e.g., @w{@samp{@command{tar} -cvf}}. Only the last option in
such a set is allowed to have an argument@footnote{Clustering many
options, the last of which has an argument, is a rather opaque way to
write options. Some wonder if @acronym{GNU} @code{getopt} should not
@item --get
@itemx -x
-Same as @option{--extract}. @xref{extract}.
+Same as @option{--extract}. @xref{extract}.
@item --list
@itemx -t
@item --check-links
@itemx -l
If this option was given, @command{tar} will check the number of links
-dumped for each processed file. If this number does not match the
+dumped for each processed file. If this number does not match the
total number of hard links for the file, a warning message will be
output.
Future versions will take @option{-l} as a short version of
-@option{--check-links}. However, current release still retains the old
+@option{--check-links}. However, current release still retains the old
semantics for @option{-l}.
@xref{Current status}, for more information.
@item --format=@var{format}
-Selects output archive format. @var{Format} may be one of the
+Selects output archive format. @var{Format} may be one of the
following:
@table @samp
1.12 or earlier.
@item gnu
-Creates archive in GNU tar 1.13 format. Basically it is the same as
+Creates archive in GNU tar 1.13 format. Basically it is the same as
@samp{oldgnu} with the only difference in the way it handles long
numeric fields.
@itemx --seek
Assume that the archive media supports seeks to arbitrary
-locations. Usually @command{tar} determines automatically whether
-the archive can be seeked or not. This option is intended for use
+locations. Usually @command{tar} determines automatically whether
+the archive can be seeked or not. This option is intended for use
in cases when such recognition fails.
@item --newer=@var{date}
@item -o
When extracting files, this option is a synonym for
-@option{--no-same-owner}, i.e. it prevents @command{tar} from
+@option{--no-same-owner}, i.e. it prevents @command{tar} from
restoring ownership of files being extracted.
When creating an archive, @option{-o} is a synonym for
-@option{--old-archive}. This behavior is for compatibility
+@option{--old-archive}. This behavior is for compatibility
with previous versions of @GNUTAR{}, and will be
removed in the future releases.
line or via @option{-T} option.
This option instructs @command{tar} to process only the @var{number}th
-occurrence of each named file. @var{Number} defaults to 1, so
+occurrence of each named file. @var{Number} defaults to 1, so
@smallexample
tar -x -f archive.tar --occurrence filename
directory.
Earlier versions of @GNUTAR{} understood @option{-l} as a
-synonym for @option{--one-file-system}. Although such usage is still
+synonym for @option{--one-file-system}. Although such usage is still
allowed in the present version, it is @emph{strongly discouraged}.
The future versions of @GNUTAR{} will use @option{-l} as
a synonym for @option{--check-links}.
@item --pax-option=@var{keyword-list}
This option is meaningful only with @acronym{POSIX.1-2001} archives
-(@FIXME-xref{}). It modifies the way @command{tar} handles the
-extended header keywords. @var{Keyword-list} is a comma-separated
+(@FIXME-xref{}). It modifies the way @command{tar} handles the
+extended header keywords. @var{Keyword-list} is a comma-separated
list of keyword options, each keyword option taking one of
the following forms:
When used in extract or list mode, this option instructs tar
to ignore any keywords matching the given @var{pattern} in the extended
-header records. In both cases, matching is performed using the pattern
+header records. In both cases, matching is performed using the pattern
matching notation described in @acronym{POSIX 1003.2}, 3.13 @FIXME-xref{see
-man 7 glob}. For example:
+man 7 glob}. For example:
@smallexample
--pax-option delete=security.*
@item exthdr.name=@var{string}
This keyword allows user control over the name that is written into the
-ustar header blocks for the extended headers. The name is obtained
+ustar header blocks for the extended headers. The name is obtained
from @var{string} after substituting the following meta-characters:
@multitable @columnfractions .30 .70
@item globexthdr.name=@var{string}
This keyword allows user control over the name that is written into
-the ustar header blocks for global extended header records. The name
+the ustar header blocks for global extended header records. The name
shall will be obtained from the contents of @var{string}, after the
following character substitutions have been made:
@noindent
where @samp{$TMPDIR} represents the value of the @var{TMPDIR}
-environment variable. If @var{TMPDIR} is not set, @command{tar}
+environment variable. If @var{TMPDIR} is not set, @command{tar}
uses @samp{/tmp}.
@item @var{keyword}=@var{value}
When used with one of archive-creation commands, these keyword/value pairs
will be included at the beginning of the archive in a global extended
-header record. When used with one of archive-reading commands,
+header record. When used with one of archive-reading commands,
@command{tar} will behave as if it has encountered these keyword/value
pairs at the beginning of the archive in a global extended header
record.
@item @var{keyword}:=@var{value}
When used with one of archive-creation commands, these keyword/value pairs
will be included as records at the beginning of an extended header for
-each file. This is effectively equivalent to @var{keyword}=@var{value}
+each file. This is effectively equivalent to @var{keyword}=@var{value}
form except that it creates no global extended header records.
When used with one of archive-reading commands, @command{tar} will
@item --show-defaults
Displays the default options used by @command{tar} and exits
-successfully. This option is intended for use in shell scripts.
+successfully. This option is intended for use in shell scripts.
Here is an example of what you can see using this option:
@smallexample
@item --show-stored-names
This option has effect only when used in conjunction with one of
-archive creation operations. It instructs tar to list the member names
+archive creation operations. It instructs tar to list the member names
stored in the archive, as opposed to the actual file
-names. @xref{listing member and file names}.
+names. @xref{listing member and file names}.
@item --sparse
@itemx -S
@item --test-label
-Reads the volume label. If an argument is specified, test whether it
-matches the volume label. @xref{--test-label option}.
+Reads the volume label. If an argument is specified, test whether it
+matches the volume label. @xref{--test-label option}.
@item --to-stdout
@itemx -O
@item --utc
-Display file modification dates in @acronym{UTC}. This option implies
+Display file modification dates in @acronym{UTC}. This option implies
@option{--verbose}.
@item --verbose
@item -l
-@option{--one-file-system}. Use of this short option is deprecated. It
+@option{--one-file-system}. Use of this short option is deprecated. It
is retained for compatibility with the earlier versions of GNU
@command{tar}, and will be changed in future releases.
When creating --- @option{--no-same-owner}, when extracting ---
@option{--portability}.
-The later usage is deprecated. It is retained for compatibility with
-the earlier versions of @GNUTAR{}. In the future releases
+The later usage is deprecated. It is retained for compatibility with
+the earlier versions of @GNUTAR{}. In the future releases
@option{-o} will be equivalent to @option{--no-same-owner} only.
@item -p
amount written to the archive, after it has been fully created.
The @value{op-checkpoint} option prints an occasional message
-as @command{tar} reads or writes the archive. In fact, it prints
-a message each 10 records read or written. It is designed for
+as @command{tar} reads or writes the archive. In fact, it prints
+a message each 10 records read or written. It is designed for
those who don't need the more detailed (and voluminous) output of
@value{op-block-number}, but do want visual confirmation that @command{tar}
is actually making forward progress.
There exists a special option that allows you to get around this
behavior and extract (or list) only a particular copy of the file.
-This is @option{--occurrence} option. If you run @command{tar} with
-this option, it will extract only the first copy of the file. You
-may also give this option an argument specifying the number of
-copy to be extracted. Thus, for example if the archive
+This is @option{--occurrence} option. If you run @command{tar} with
+this option, it will extract only the first copy of the file. You
+may also give this option an argument specifying the number of
+copy to be extracted. Thus, for example if the archive
@file{archive.tar} contained three copies of file @file{myfile}, then
the command
@end smallexample
@noindent
-would extract only the second copy. @xref{Option Summary,---occurrence}, for the description of @value{op-occurrence} option.
+would extract only the second copy. @xref{Option Summary,---occurrence}, for the description of @value{op-occurrence} option.
@FIXME{ hag -- you might want to incorporate some of the above into the
MMwtSN node; not sure. i didn't know how to make it simpler...
Both @option{--update} and @option{--append} work by adding to the end
of the archive. When you extract a file from the archive, only the
version stored last will wind up in the file system, unless you use
-the @value{op-backup} option. @FIXME-ref{Multiple Members with the
+the @value{op-backup} option. @FIXME-ref{Multiple Members with the
Same Name}
@menu
already exist and must have been created using compatible format
parameters. @FIXME-pxref{Matching Format Parameters}The new,
concatenated archive will be called by the same name as the first
-archive listed on the command line. @FIXME{is there a way to specify a
+archive listed on the command line. @FIXME{is there a way to specify a
new name?}
Like @value{op-append}, this operation cannot be performed on some
Normally, @command{tar} stops reading when it encounters a block of zeros
between file entries (which usually indicates the end of the archive).
@value{op-ignore-zeros} allows @command{tar} to completely read an archive
-which contains a block of zeros before the end (i.e.@: a damaged
-archive, or one which was created by concatenating several archives
+which contains a block of zeros before the end (i.e., a damaged
+archive, or one that was created by concatenating several archives
together).
The @value{op-ignore-zeros} option is turned off by default because many
@table @option
@item --ignore-zeros
@itemx -i
-To ignore blocks of zeros (ie.@: end-of-archive entries) which may be
+To ignore blocks of zeros (i.e., end-of-archive entries) which may be
encountered while reading an archive. Use in conjunction with
@value{op-extract} or @value{op-list}.
@end table
@table @option
@item --keep-newer-files
Do not replace existing files that are newer than their archive
-copies. This option is meaningless with @value{op-list}.
+copies. This option is meaningless with @value{op-list}.
@end table
@node Unlink First
medium is a @dfn{pipe}, which is one a Unix redirection mechanism:
@smallexample
-$ @kbd{cd sourcedir; tar -cf - . | (cd targetdir; tar -xf -)}
+$ @kbd{cd sourcedir; tar -cf - . | (cd targetdir; tar -xf -)}
@end smallexample
@noindent
The command also works using short option forms:
@smallexample
-$ @w{@kbd{cd sourcedir; tar --create --file=- . | (cd targetdir; tar --extract --file=-)}}
+$ @w{@kbd{cd sourcedir; tar --create --file=- . | (cd targetdir; tar --extract --file=-)}}
@end smallexample
@noindent
@smallexample
.* dumps
-. + what are dumps
+. + what are dumps
-. + different levels of dumps
+. + different levels of dumps
. - full dump = dump everything
. - level 1, level 2 dumps etc, -
A level n dump dumps everything changed since the last level
n-1 dump (?)
-. + how to use scripts for dumps (ie, the concept)
+. + how to use scripts for dumps (ie, the concept)
. - scripts to run after editing backup specs (details)
-. + Backup Specs, what is it.
+. + Backup Specs, what is it.
. - how to customize
. - actual text of script [/sp/dump/backup-specs]
-. + Problems
+. + Problems
. - rsh doesn't work
. - rtape isn't installed
. - (others?)
-. + the --incremental option of tar
+. + the --incremental option of tar
-. + tapes
+. + tapes
. - write protection
. - types of media
. : different sizes and types, useful for different things
incremental backup. It has much the same effect as
@value{op-incremental}, but also the time when the dump is done and
the list of directories dumped is written to the given
-@var{file}. When restoring, only files newer than the saved time are
+@var{file}. When restoring, only files newer than the saved time are
restored, and the directory list is used to speed up operations.
@value{op-listed-incremental} acts like @value{op-incremental}, but when
and @samp{/var}.
@smallexample
-#! /bin/sh
+#! /bin/sh
tar --create \
--blocking-factor=126 \
--file=/dev/rmt/0 \
actually created.
Incremental dumps depend crucially on time stamps, so the results are
-unreliable if you modify a file's time stamps during dumping (e.g.@:
+unreliable if you modify a file's time stamps during dumping (e.g.,
with the @option{--atime-preserve} option), or if you set the clock
backwards.
Before you use these scripts, you need to edit the file
@file{backup-specs}, which specifies parameters used by the backup
-scripts and by the restore script. This file is usually located
-in @file{/etc/backup} directory. @FIXME-xref{Script Syntax} Once the
+scripts and by the restore script. This file is usually located
+in @file{/etc/backup} directory. @FIXME-xref{Script Syntax} Once the
backup parameters are set, you can perform backups or restoration by
running the appropriate script.
-The name of the backup script is @code{backup}. The name of the
-restore script is @code{restore}. The following sections describe
+The name of the backup script is @code{backup}. The name of the
+restore script is @code{restore}. The following sections describe
their use in detail.
@emph{Please Note:} The backup and restoration scripts are
designed to be used together. While it is possible to restore files by
hand from an archive which was created using a backup script, and to create
an archive by hand which could then be extracted using the restore script,
-it is easier to use the scripts. @value{xref-incremental}, and
+it is easier to use the scripts. @value{xref-incremental}, and
@value{xref-listed-incremental}, before making such an attempt.
@node Backup Parameters
before using these scripts.
Syntactically, @file{backup-specs} is a shell script, containing
-mainly variable assignments. However, any valid shell construct
-is allowed in this file. Particularly, you may wish to define
-functions within that script (e.g. see @code{RESTORE_BEGIN} below).
+mainly variable assignments. However, any valid shell construct
+is allowed in this file. Particularly, you may wish to define
+functions within that script (e.g., see @code{RESTORE_BEGIN} below).
For more information about shell script syntax, please refer to
@url{http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#ta
-g_02, the definition of the Shell Command Language}. See also
+g_02, the definition of the Shell Command Language}. See also
@ref{Top,,Bash Features,bashref,Bash Reference Manual}.
The shell variables controlling behavior of @code{backup} and
@subsection General-Purpose Variables
@defvr {Backup variable} ADMINISTRATOR
-The user name of the backup administrator. @code{Backup} scripts
+The user name of the backup administrator. @code{Backup} scripts
sends a backup report to this address.
@end defvr
@defvr {Backup variable} BACKUP_HOUR
-The hour at which the backups are done. This can be a number from 0
+The hour at which the backups are done. This can be a number from 0
to 23, or the time specification in form @var{hours}:@var{minutes},
or the string @samp{now}.
-This variable is used by @code{backup}. Its value may be overridden
+This variable is used by @code{backup}. Its value may be overridden
using @option{--time} option (@pxref{Scripted Backups}).
@end defvr
@defvr {Backup variable} TAPE_FILE
-The device @command{tar} writes the archive to. If @var{TAPE_FILE}
+The device @command{tar} writes the archive to. If @var{TAPE_FILE}
is a remote archive (@pxref{remote-dev}), backup script will suppose
-that your @command{mt} is able to access remote devices. If @var{RSH}
+that your @command{mt} is able to access remote devices. If @var{RSH}
(@pxref{RSH}) is set, @option{--rsh-command} option will be added to
-invocations of @command{mt}.
+invocations of @command{mt}.
@end defvr
@defvr {Backup variable} BLOCKING
@defvr {Backup variable} BACKUP_DIRS
A list of file systems to be dumped (for @code{backup}), or restored
-(for @code{restore}). You can include any directory
+(for @code{restore}). You can include any directory
name in the list --- subdirectories on that file system will be
included, regardless of how they may look to other networked machines.
Subdirectories on other file systems will be ignored.
the host machine must have @GNUTAR{} installed, and
must be able to access the directory containing the backup scripts and
their support files using the same file name that is used on the
-machine where the scripts are run (ie. what @command{pwd} will print
+machine where the scripts are run (ie. what @command{pwd} will print
when in that directory on that machine). If the host that contains
the file system does not have this capability, you can specify another
host as long as it can access the file system through NFS.
If the list of file systems is very long you may wish to put it
-in a separate file. This file is usually named
+in a separate file. This file is usually named
@file{/etc/backup/dirs}, but this name may be overridden in
@file{backup-specs} using @code{DIRLIST} variable.
@end defvr
@defvr {Backup variable} DIRLIST
A path to the file containing the list of the filesystems to backup
-or restore. By default it is @file{/etc/backup/dirs}.
+or restore. By default it is @file{/etc/backup/dirs}.
@end defvr
@defvr {Backup variable} BACKUP_FILES
A list of individual files to be dumped (for @code{backup}), or restored
-(for @code{restore}). These should be accessible from the machine on
+(for @code{restore}). These should be accessible from the machine on
which the backup script is run.
If the list of file systems is very long you may wish to store it
-in a separate file. This file is usually named
+in a separate file. This file is usually named
@file{/etc/backup/files}, but this name may be overridden in
@file{backup-specs} using @code{FILELIST} variable.
@end defvr
@defvr {Backup variable} FILELIST
A path to the file containing the list of the individual files to backup
-or restore. By default it is @file{/etc/backup/files}.
+or restore. By default it is @file{/etc/backup/files}.
@end defvr
@defvr {Backup variable} MT
@defvr {Backup variable} RSH
@anchor{RSH}
-Full file name of @command{rsh} binary or its equivalent. You may wish to
-set it to @code{ssh}, to improve security. In this case you will have
+Full file name of @command{rsh} binary or its equivalent. You may wish to
+set it to @code{ssh}, to improve security. In this case you will have
to use public key authentication.
@end defvr
@defvr {Backup variable} RSH_COMMAND
-Full file name of @command{rsh} binary on remote mashines. This will
+Full file name of @command{rsh} binary on remote mashines. This will
be passed via @option{--rsh-command} option to the remote invocation
-of @GNUTAR{}.
+of @GNUTAR{}.
@end defvr
@defvr {Backup variable} VOLNO_FILE
@defvr {Backup variable} XLIST
-Name of @dfn{exclude file list}. An @dfn{exclude file list} is a file
+Name of @dfn{exclude file list}. An @dfn{exclude file list} is a file
located on the remote machine and containing the list of files to
-be excluded from the backup. Exclude file lists are searched in
-/etc/tar-backup directory. A common use for exclude file lists
+be excluded from the backup. Exclude file lists are searched in
+/etc/tar-backup directory. A common use for exclude file lists
is to exclude files containing security-sensitive information
-(e.g. @file{/etc/shadow} from backups).
+(e.g., @file{/etc/shadow} from backups).
This variable affects only @code{backup}.
@end defvr
@defvr {Backup variable} DUMP_REMIND_SCRIPT
Script to be run when it's time to insert a new tape in for the next
-volume. Administrators may want to tailor this script for their site.
+volume. Administrators may want to tailor this script for their site.
If this variable isn't set, @GNUTAR{} will display its built-in prompt
@FIXME-xref{describe it somewhere!}, and will expect confirmation from
the console.
@defvr {Backup variable} TAR
-Full file name of the @GNUTAR{} executable. If this is not set, backup
+Full file name of the @GNUTAR{} executable. If this is not set, backup
scripts will search @command{tar} in the current shell path.
@end defvr
Backup scripts access tape device using special @dfn{hook functions}.
These functions take a single argument -- the name of the tape
-device. Their names are kept in the following variables:
+device. Their names are kept in the following variables:
@defvr {Backup variable} MT_BEGIN
-The name of @dfn{begin} function. This function is called before
-accessing the drive. By default it retensions the tape:
+The name of @dfn{begin} function. This function is called before
+accessing the drive. By default it retensions the tape:
@smallexample
MT_BEGIN=mt_begin
@end defvr
@defvr {Backup variable} MT_REWIND
-The name of @dfn{rewind} function. The default definition is as
+The name of @dfn{rewind} function. The default definition is as
follows:
@smallexample
@end defvr
@defvr {Backup variable} MT_OFFLINE
-The name of the function switching the tape off line. By default
+The name of the function switching the tape off line. By default
it is defined as follows:
@smallexample
@defvr {Backup variable} MT_STATUS
The name of the function used to obtain the status of the archive device,
-including error count. Default definition:
+including error count. Default definition:
@smallexample
MT_STATUS=mt_status
@subsection User Hooks
@dfn{User hooks} are shell functions executed before and after
-each @command{tar} invocation. Thus, there are @dfn{backup
+each @command{tar} invocation. Thus, there are @dfn{backup
hooks}, which are executed before and after dumping each file
system, and @dfn{restore hooks}, executed before and
-after restoring a file system. Each user hook is a shell function
+after restoring a file system. Each user hook is a shell function
taking four arguments:
@deffn {User Hook Function} hook @var{level} @var{host} @var{fs} @var{fsname}
Full path name to the filesystem being dumped or restored.
@item fsname
-Filesystem name with directory separators replaced with colons. This
-is useful e.g. for creating unique files.
+Filesystem name with directory separators replaced with colons. This
+is useful, e.g., for creating unique files.
@end table
@end deffn
Following variables keep the names of user hook functions
@defvr {Backup variable} DUMP_BEGIN
-Dump begin function. It is executed before dumping the filesystem.
+Dump begin function. It is executed before dumping the filesystem.
@end defvr
@defvr {Backup variable} DUMP_END
backup --level=@var{level} --time=@var{time}
@end smallexample
-The @option{level} option requests the dump level. Thus, to produce
+The @option{level} option requests the dump level. Thus, to produce
a full dump, specify @code{--level=0} (this is the default, so
@option{--level} may be omitted if its value is @code{0}).
@footnote{For backward compatibility, the @code{backup} will also
try to deduce the requested dump level from the name of the
-script itself. If the name consists of a string @samp{level-}
+script itself. If the name consists of a string @samp{level-}
followed by a single decimal digit, that digit is taken as
-the dump level number. Thus, you may create a link from @code{backup}
+the dump level number. Thus, you may create a link from @code{backup}
to @code{level-1} and then run @code{level-1} whenever you need to
create a level one dump.}
The @option{--time} option determines when should the backup be
-run. @var{Time} may take three forms:
+run. @var{Time} may take three forms:
@table @asis
@item @var{hh}:@var{mm}
@item -v[@var{level}]
@itemx --verbose[=@var{level}]
-Set verbosity level. The higher the level is, the more debugging
-information will be output during execution. Devault @var{level}
+Set verbosity level. The higher the level is, the more debugging
+information will be output during execution. Devault @var{level}
is 100, which means the highest debugging level.
@item -t @var{start-time}
@section Using the Restore Script
To restore files that were archived using a scripted backup, use the
-@code{restore} script. Its usage is quite straightforward. In the
+@code{restore} script. Its usage is quite straightforward. In the
simplest form, invoke @code{restore --all}, it will
then restore all the filesystems and files specified in
@file{backup-specs} (@pxref{General-Purpose Variables,BACKUP_DIRS}).
You may select the filesystems (and/or files) to restore by
giving @code{restore} list of @dfn{patterns} in its command
-line. For example, running
+line. For example, running
@smallexample
restore 'albert:*'
@end smallexample
@noindent
-will restore all filesystems on the machine @samp{albert}. A more
+will restore all filesystems on the machine @samp{albert}. A more
complicated example:
@smallexample
By default @code{restore} will start restoring files from the lowest
available dump level (usually zero) and will continue through
-all available dump levels. There may be situations where such a
-thorough restore is not necessary. For example, you may wish to
-restore only files from the recent level one backup. To do so,
+all available dump levels. There may be situations where such a
+thorough restore is not necessary. For example, you may wish to
+restore only files from the recent level one backup. To do so,
use @option{--level} option, as shown in the example below:
@smallexample
@item -v[@var{level}]
@itemx --verbose[=@var{level}]
-Set verbosity level. The higher the level is, the more debugging
-information will be output during execution. Devault @var{level}
+Set verbosity level. The higher the level is, the more debugging
+information will be output during execution. Devault @var{level}
is 100, which means the highest debugging level.
@item -h
If you do not name the archive, @command{tar} uses the value of the
environment variable @env{TAPE} as the file name for the archive. If
that is not available, @command{tar} uses a default, compiled-in archive
-name, usually that for tape unit zero (ie. @file{/dev/tu00}).
+name, usually that for tape unit zero (ie. @file{/dev/tu00}).
@command{tar} always needs an archive name.
If you use @file{-} as an @var{archive-name}, @command{tar} reads the
"notable tar usages".}
@smallexample
-$ @kbd{cd sourcedir; tar -cf - . | (cd targetdir; tar -xf -)}
+$ @kbd{cd sourcedir; tar -cf - . | (cd targetdir; tar -xf -)}
@end smallexample
@FIXME{help!}
have the @file{rmt} program installed (This command is included in
the @GNUTAR{} distribution and by default is installed under
@file{@var{prefix}/libexec/rmt}, were @var{prefix} means your
-installation prefix). If you need to use a file whose name includes a
+installation prefix). If you need to use a file whose name includes a
colon, then the remote tape drive behavior
can be inhibited by using the @value{op-force-local} option.
@value{op-files-from} option to @command{tar}. Give the name of the file
which contains the list of files to include as the argument to
@option{--files-from}. In the list, the file names should be separated by
-newlines. You will frequently use this option when you have generated
+newlines. You will frequently use this option when you have generated
the list of files to archive with the @command{find} utility.
@table @option
more information.)
@smallexample
-$ @kbd{find . -size -400 -print > small-files}
+$ @kbd{find . -size -400 -print > small-files}
$ @kbd{tar -c -v -z -T small-files -f little.tgz}
@end smallexample
@noindent
In this example, @command{tar} will first switch to @file{/etc}
directory and add files @file{passwd} and @file{hosts} to the
-archive. Then it will change to @file{/lib} directory and will archive
-the file @file{libc.a}. Thus, the resulting archive @file{foo.tar} will
+archive. Then it will change to @file{/lib} directory and will archive
+the file @file{libc.a}. Thus, the resulting archive @file{foo.tar} will
contain:
@smallexample
@noindent
Notice that the option parsing algorithm used with @option{-T} is
-stricter than the one used by shell. Namely, when specifying option
+stricter than the one used by shell. Namely, when specifying option
arguments, you should observe the following rules:
@itemize @bullet
@item
When using short (single-letter) option form, its argument must
immediately follow the option letter, without any intervening
-whitespace. For example: @code{-Cdir}.
+whitespace. For example: @code{-Cdir}.
@item
When using long option form, the option argument must be separated
-from the option by a single equal sign. No whitespace is allowed on
-any side of the equal sign. For example: @code{--directory=dir}.
+from the option by a single equal sign. No whitespace is allowed on
+any side of the equal sign. For example: @code{--directory=dir}.
@item
For both short and long option forms, the option argument can be given
@cindex @option{--add-file}
If you happen to have a file whose name starts with @samp{-},
precede it with @option{--add-file} option to prevent it from
-being recognized as an option. For example: @code{--add-file --my-file}.
+being recognized as an option. For example: @code{--add-file --my-file}.
@menu
* nul::
This example shows how to use @command{find} to generate a list of files
larger than 800K in length and put that list into a file called
-@file{long-files}. The @option{-print0} option to @command{find} is just
+@file{long-files}. The @option{-print0} option to @command{find} is just
like @option{-print}, except that it separates files with a @code{NUL}
rather than with a newline. You can then run @command{tar} with both the
@option{--null} and @option{-T} options to specify that @command{tar} get the
@command{tar} to recognize the @code{NUL} separator between files.
@smallexample
-$ @kbd{find . -size +800 -print0 > long-files}
+$ @kbd{find . -size +800 -print0 > long-files}
$ @kbd{tar -c -v --null --files-from=long-files --file=big.tar}
@end smallexample
@item --anchored
@itemx --no-anchored
If anchored, a pattern must match an initial subsequence
-of the name's components. Otherwise, the pattern can match any
-subsequence. Default is @option{--no-anchored}.
+of the name's components. Otherwise, the pattern can match any
+subsequence. Default is @option{--no-anchored}.
@item --ignore-case
@itemx --no-ignore-case
directory entries themselves, but does not descend on them
recursively. Many people use @command{find} for locating files they
want to back up, and since @command{tar} @emph{usually} recursively
-descends on directories, they have to use the @samp{@w{! -d}} option
+descends on directories, they have to use the @samp{@w{! -d}} option
to @command{find} @FIXME{needs more explanation or a cite to another
info file}as they usually do not want all the files in a directory.
They then use the @value{op-files-from} option to archive the files
@option{--directory} option.
When using @option{--files-from} (@pxref{files}), you can put various
-@command{tar} options (including @option{-C}) in the file list. Notice,
+@command{tar} options (including @option{-C}) in the file list. Notice,
however, that in this case the option and its argument may not be
-separated by whitespace. If you use short option, its argument must
+separated by whitespace. If you use short option, its argument must
either follow the option letter immediately, without any intervening
-whitespace, or occupy the next line. Otherwise, if you use long
+whitespace, or occupy the next line. Otherwise, if you use long
option, separate its argument by an equal sign.
For instance, the file list for the above example will be:
@end smallexample
Notice also that you can only use the short option variant in the file
-list, i.e. always use @option{-C}, not @option{--directory}.
+list, i.e., always use @option{-C}, not @option{--directory}.
The interpretation of @value{op-directory} is disabled by
@value{op-null} option.
be @file{bin/ls}.@footnote{A side effect of this is that when
@option{--create} is used with @option{--verbose} the resulting output
is not, generally speaking, the same as the one you'd get running
-@kbd{tar --list} command. This may be important if you use some
-scripts for comparing both outputs. @xref{listing member and file names},
+@kbd{tar --list} command. This may be important if you use some
+scripts for comparing both outputs. @xref{listing member and file names},
for the information on how to handle this case.}
If you use the @value{op-absolute-names} option, @command{tar} will do
@table @asis
@item gnu
-Format used by @GNUTAR{} versions up to 1.13.25. This format derived
+Format used by @GNUTAR{} versions up to 1.13.25. This format derived
from an early @acronym{POSIX} standard, adding some improvements such as
-sparse file handling and incremental archives. Unfortunately these
+sparse file handling and incremental archives. Unfortunately these
features were implemented in a way incompatible with other archive
formats.
Format used by @GNUTAR{} of versions prior to 1.12.
@item v7
-Archive format, compatible with the V7 implementation of tar. This
-format imposes a number of limitations. The most important of them
+Archive format, compatible with the V7 implementation of tar. This
+format imposes a number of limitations. The most important of them
are:
@enumerate
@end enumerate
This format has traditionally been used by Automake when producing
-Makefiles. This practice will change in the future, in the meantime,
+Makefiles. This practice will change in the future, in the meantime,
however this means that projects containing filenames more than 99
characters long will not be able to use @GNUTAR{} @value{VERSION} and
Automake prior to 1.9.
@item ustar
-Archive format defined by @acronym{POSIX.1-1988} specification. It stores
-symbolic ownership information. It is also able to store
-special files. However, it imposes several restrictions as well:
+Archive format defined by @acronym{POSIX.1-1988} specification. It stores
+symbolic ownership information. It is also able to store
+special files. However, it imposes several restrictions as well:
@enumerate
@item The maximum length of a file name is limited to 256 characters,
provided that the filename can be split at directory separator in
-two parts, first of them being at most 155 bytes long. So, in most
+two parts, first of them being at most 155 bytes long. So, in most
cases the maximum file name length will be shorter than 256
characters.
@item The maximum length of a symbolic link name is limited to
@item star
Format used by J@"org Schilling @command{star}
-implementation. @GNUTAR{} is able to read @samp{star} archives but
+implementation. @GNUTAR{} is able to read @samp{star} archives but
currently does not produce them.
@item posix
-Archive format defined by @acronym{POSIX.1-2001} specification. This is the
-most flexible and feature-rich format. It does not impose any
-restrictions on file sizes or filename lengths. This format is quite
+Archive format defined by @acronym{POSIX.1-2001} specification. This is the
+most flexible and feature-rich format. It does not impose any
+restrictions on file sizes or filename lengths. This format is quite
recent, so not all tar implementations are able to handle it properly.
However, this format is designed in such a way that any tar
implementation able to read @samp{ustar} archives will be able to read
@end multitable
The default format for @GNUTAR{} is defined at compilation
-time. You may check it by running @command{tar --help}, and examining
-the last lines of its output. Usually, @GNUTAR{} is configured
+time. You may check it by running @command{tar --help}, and examining
+the last lines of its output. Usually, @GNUTAR{} is configured
to create archives in @samp{gnu} format, however, future version will
switch to @samp{posix}.
versions, specify the @value{op-format-v7} option in
conjunction with the @value{op-create} (@command{tar} also
accepts @option{--portability} or @samp{op-old-archive} for this
-option). When you specify it,
+option). When you specify it,
@command{tar} leaves out information about directories, pipes, fifos,
contiguous files, and device files, and specifies file ownership by
group and user IDs instead of group and user names.
@subsection Ustar Archive Format
Archive format defined by @acronym{POSIX}.1-1988 specification is called
-@code{ustar}. Although it is more flexible than the V7 format, it
+@code{ustar}. Although it is more flexible than the V7 format, it
still has many restrictions (@xref{Formats,ustar}, for the detailed
-description of @code{ustar} format). Along with V7 format,
+description of @code{ustar} format). Along with V7 format,
@code{ustar} format is a good choice for archives intended to be read
with other implementations of @command{tar}.
@command{tar} programs that follow it.
In the majority of cases, @command{tar} will be configured to create
-this format by default. This will change in the future releases, since
+this format by default. This will change in the future releases, since
we plan to make @samp{posix} format the default.
To force creation a @GNUTAR{} archive, use option
-@value{op-format-gnu}.
+@value{op-format-gnu}.
Some @command{tar} options are currently basing on @GNUTAR{}
format, and can therefore be used only with @samp{gnu}
-or @samp{oldgnu} archive formats. The list of such options follows:
+or @samp{oldgnu} archive formats. The list of such options follows:
@itemize @bullet
@item @value{op-label}, when used with @value{op-create}.
A @acronym{POSIX} conformant archive will be created if @command{tar}
was given @value{op-format-posix} option.
Notice, that currently @acronym{GNU} extensions are not
-allowed with this format. Following is the list of options that
+allowed with this format. Following is the list of options that
cannot be used with @value{op-format-posix}:
@itemize @bullet
Portable archives should avoid members of 8 GB or larger, as @acronym{POSIX}
@command{tar} format cannot represent them.
-Portable archives should avoid time stamps from the future. @acronym{POSIX}
+Portable archives should avoid time stamps from the future. @acronym{POSIX}
@command{tar} format can represent time stamps in the range 1970-01-01
00:00:00 through 2242-03-16 12:56:31 @sc{utc}. However, many current
hosts use a signed 32-bit @code{time_t}, or internal time stamp format,
@cindex Compressed archives
@cindex Storing archives in compressed format
-@GNUTAR{} is able to create and read compressed archives. It supports
-@command{gzip} and @command{bzip2} compression programs. For backward
+@GNUTAR{} is able to create and read compressed archives. It supports
+@command{gzip} and @command{bzip2} compression programs. For backward
compatibilty, it also supports @command{compress} command, although
we strongly recommend against using it, since there is a patent
covering the algorithm it uses and you could be sued for patent
-infringement merely by running @command{compress}! Besides, it is less
+infringement merely by running @command{compress}! Besides, it is less
effective than @command{gzip} and @command{bzip2}.
Creating a compressed archive is simple: you just specify a
@dfn{compression option} along with the usual archive creation
-commands. The compression option is @option{-z} (@option{--gzip}) to
+commands. The compression option is @option{-z} (@option{--gzip}) to
create a @command{gzip} compressed archive, @option{-j}
(@option{--bzip2}) to create a @command{bzip2} compressed archive, and
@option{-Z} (@option{--compress}) to use @command{compress} program.
Reading compressed archive is even simpler: you don't need to specify
any additional options as @GNUTAR{} recognizes its format
-automatically. Thus, the following commands will list and extract the
+automatically. Thus, the following commands will list and extract the
archive created in previous example:
@smallexample
The only case when you have to specify a decompression option while
reading the archive is when reading from a pipe or from a tape drive
-that does not support random access. However, in this case @GNUTAR{}
-will indicate which option you should use. For example:
+that does not support random access. However, in this case @GNUTAR{}
+will indicate which option you should use. For example:
@smallexample
$ @kbd{cat archive.tar.gz | tar tf -}
-tar: Archive is compressed. Use -z option
+tar: Archive is compressed. Use -z option
tar: Error is not recoverable: exiting now
@end smallexample
@end smallexample
Notice also, that there are several restrictions on operations on
-compressed archives. First of all, compressed archives cannot be
-modified, i.e. you cannot update (@value{op-update}) them or delete
-(@value{op-delete}) members from them. Likewise, you cannot append
+compressed archives. First of all, compressed archives cannot be
+modified, i.e., you cannot update (@value{op-update}) them or delete
+(@value{op-delete}) members from them. Likewise, you cannot append
another @command{tar} archive to a compressed archive using
-@value{op-append}). Secondly, multi-volume archives cannot be
+@value{op-append}). Secondly, multi-volume archives cannot be
compressed.
The following table summarizes compression options used by @GNUTAR{}.
@command{compress}.
@item --use-compress-program=@var{prog}
-Use external compression program @var{prog}. Use this option if you
-have a compression program that @GNUTAR{} does not support. There
+Use external compression program @var{prog}. Use this option if you
+have a compression program that @GNUTAR{} does not support. There
are two requirements to which @var{prog} should comply:
First, when called without options, it should read data from standard
input, compress it and output it on standard output.
Secondly, if called with @option{-d} argument, it should do exactly
-the opposite, i.e. read the compressed data from the standard input
+the opposite, i.e., read the compressed data from the standard input
and produce uncompressed data on the standard output.
@end table
@FIXME{I have one question, or maybe it's a suggestion if there isn't a way
-to do it now. I would like to use @value{op-gzip}, but I'd also like
+to do it now. I would like to use @value{op-gzip}, but I'd also like
the output to be fed through a program like @acronym{GNU}
@command{ecc} (actually, right now that's @samp{exactly} what I'd like
to use :-)), basically adding ECC protection on top of compression.
Extract all protection information.
This option causes @command{tar} to set the modes (access permissions) of
-extracted files exactly as recorded in the archive. If this option
+extracted files exactly as recorded in the archive. If this option
is not used, the current @code{umask} setting limits the permissions
-on extracted files. This option is by default enabled when
+on extracted files. This option is by default enabled when
@command{tar} is executed by a superuser.
Physically, an archive consists of a series of file entries terminated
by an end-of-archive entry, which consists of two 512 blocks of zero
-bytes. A file
+bytes. A file
entry usually describes one of the files in the archive (an
@dfn{archive member}), and consists of a file header and the contents
of the file. File headers contain file names and statistics, checksum
of the file. At the end of the archive file there are two 512-byte blocks
filled with binary zeros as an end-of-file marker. A reasonable system
should write such end-of-file marker at the end of an archive, but
-must not assume that such a block exists when reading an archive. In
+must not assume that such a block exists when reading an archive. In
particular @GNUTAR{} always issues a warning if it does not encounter it.
The blocks may be @dfn{blocked} for physical I/O operations.
permissions, the mode bit(s) specifying those special permissions
are ignored. Modes which are not supported by the operating system
restoring files from the archive will be ignored. Unsupported modes
-should be faked up when creating or updating an archive; e.g.@: the
+should be faked up when creating or updating an archive; e.g., the
group permission could be copied from the @emph{other} permission.
The @code{uid} and @code{gid} fields are the numeric user and group
@quotation
Is there any differences between the ability to recover crashed
-archives between the two of them. (Is there any chance of recovering
+archives between the two of them. (Is there any chance of recovering
crashed archives at all.)
@end quotation
sign (@samp{@@}), it is treated as @samp{user@@hostname:file name}. In
either case, @command{tar} will invoke the command @command{rsh} (or
@command{remsh}) to start up an @command{/usr/libexec/rmt} on the remote
-machine. If you give an alternate login name, it will be given to the
+machine. If you give an alternate login name, it will be given to the
@command{rsh}.
Naturally, the remote machine must have an executable
-@command{/usr/libexec/rmt}. This program is free software from the
+@command{/usr/libexec/rmt}. This program is free software from the
University of California, and a copy of the source code can be found
with the sources for @command{tar}; it's compiled and installed by default.
The exact path to this utility is determined when configuring the package.
It is @file{@var{prefix}/libexec/rmt}, where @var{prefix} stands for
-your installation prefix. This location may also be overridden at
+your installation prefix. This location may also be overridden at
runtime by using @value{op-rmt-command} option (@xref{Option Summary,
----rmt-command}, for detailed description of this option. @xref{Remote
+---rmt-command}, for detailed description of this option. @xref{Remote
Tape Server}, for the description of @command{rmt} command).
If this option is not given, but the environment variable @env{TAPE}
A copy of the source for the remote tape server is provided. It is
Copyright @copyright{} 1983 by the Regents of the University of
-California, but can be freely distributed. It is compiled and
+California, but can be freely distributed. It is compiled and
installed by default.
@cindex absolute file names
The data in an archive is grouped into blocks, which are 512 bytes.
Blocks are read and written in whole number multiples called
-@dfn{records}. The number of blocks in a record (ie. the size of a
+@dfn{records}. The number of blocks in a record (ie. the size of a
record in units of 512 bytes) is called the @dfn{blocking factor}.
The @value{op-blocking-factor} option specifies the blocking factor of
-an archive. The default blocking factor is typically 20 (ie.@:
+an archive. The default blocking factor is typically 20 (i.e.,
10240 bytes), but can be specified at installation. To find out
the blocking factor of an existing archive, use @samp{tar --list
--file=@var{archive-name}}. This may not work on some devices.
Records are separated by gaps, which waste space on the archive media.
If you are archiving on magnetic tape, using a larger blocking factor
(and therefore larger records) provides faster throughput and allows you
-to fit more data on a tape (because there are fewer gaps). If you are
+to fit more data on a tape (because there are fewer gaps). If you are
archiving on cartridge, a very large blocking factor (say 126 or more)
-greatly increases performance. A smaller blocking factor, on the other
+greatly increases performance. A smaller blocking factor, on the other
hand, may be useful when archiving small files, to avoid archiving lots
of nulls as @command{tar} fills out the archive to the end of the record.
In general, the ideal record size depends on the size of the
blocking factor (particularly if you're not sure what the blocking factor
is), you can usually use the @value{op-read-full-records} option while
specifying a blocking factor larger then the blocking factor of the archive
-(ie. @samp{tar --extract --read-full-records --blocking-factor=300}.
+(ie. @samp{tar --extract --read-full-records --blocking-factor=300}.
@xref{list}, for more information on the @value{op-list}
operation. @xref{Reading}, for a more detailed explanation of that option.
data on the tape will be overwritten (unless it is no longer needed).
Before reading an archive, you should make sure the tape head is at
the beginning of the archive you want to read. (The @code{restore}
-script will find the archive automatically. @FIXME-xref{Scripted Restoration}@xref{mt}, for
+script will find the archive automatically. @FIXME-xref{Scripted Restoration}@xref{mt}, for
an explanation of the tape moving utility.
If you want to add new archive file entries to a tape, you should
Moves tape position back @var{number} files.
@item rewind
-Rewinds the tape. (Ignores @var{number}).
+Rewinds the tape. (Ignores @var{number}).
@item offline
@itemx rewoff1
-Rewinds the tape and takes the tape device off-line. (Ignores @var{number}).
+Rewinds the tape and takes the tape device off-line. (Ignores @var{number}).
@item status
Prints status information about the tape unit.
that volume), use @value{op-extract}, again without
@value{op-multi-volume}.
-If an archive member is split across volumes (ie. its entry begins on
+If an archive member is split across volumes (ie. its entry begins on
one volume of the media and ends on another), you need to specify
@value{op-multi-volume} to extract it successfully. In this case, you
should load the volume where the archive member starts, and use
@FIXME{example}
@FIXME{There should be a sample program here, including an exit
-before end. Is the exit status even checked in tar? :-(}
+before end. Is the exit status even checked in tar? :-(}
@table @option
@item --multi-volume
@cindex Volume label, listing
@cindex Listing volume label
The volume label will be displayed by @option{--list} along with
-the file contents. If verbose display is requested, it will also be
+the file contents. If verbose display is requested, it will also be
explicitely marked as in the example below:
@smallexample
@anchor{--test-label option}
However, @option{--list} option will cause listing entire
contents of the archive, which may be undesirable (for example, if the
-archive is stored on a tape). You can request checking only the volume
-by specifying @option{--test-label} option. This option reads only the
+archive is stored on a tape). You can request checking only the volume
+by specifying @option{--test-label} option. This option reads only the
first block of an archive, so it can be used with slow storage
-devices. For example:
+devices. For example:
@smallexample
@group
If @option{--test-label} is used with a single command line
argument, @command{tar} compares the volume label with the
-argument. It exits with code 0 if the two strings match, and with code
-2 otherwise. In this case no output is displayed. For example:
+argument. It exits with code 0 if the two strings match, and with code
+2 otherwise. In this case no output is displayed. For example:
@smallexample
@group
If you request any operation, other than @option{--create}, along
with using @option{--label} option, @command{tar} will first check if
the archive label matches the one specified and will refuse to proceed
-if it does not. Use this as a safety precaution to avoid accidentally
-overwriting existing archives. For example, if you wish to add files
+if it does not. Use this as a safety precaution to avoid accidentally
+overwriting existing archives. For example, if you wish to add files
to @file{archive}, presumably labelled with string @samp{My volume},
you will get:
@end smallexample
@noindent
-in case its label does not match. This will work even if
+in case its label does not match. This will work even if
@file{archive} is not labelled at all.
Similarly, @command{tar} will refuse to list or extract the
archive if its label doesn't match the @var{archive-label}
-specified. In those cases, @var{archive-label} argument is interpreted
+specified. In those cases, @var{archive-label} argument is interpreted
as a globbing-style pattern which must match the actual magnetic
volume label. @xref{exclude}, for a precise description of how match
is attempted@footnote{Previous versions of @command{tar} used full
regular expression matching, or before that, only exact string
matching, instead of wildcard matchers. We decided for the sake of
simplicity to use a uniform matching device through
-@command{tar}.}. If the switch @value{op-multi-volume} is being used,
+@command{tar}.}. If the switch @value{op-multi-volume} is being used,
the volume label matcher will also suffix @var{archive-label} by
@w{@samp{ Volume [1-9]*}} if the initial match fails, before giving
up. Since the volume numbering is automatically added in labels at
creation time, it sounded logical to equally help the user taking care
-of it when the archive is being read.
+of it when the archive is being read.
The @value{op-label} was once called @option{--volume}, but is not available
under that name anymore.
projects / chaz / tar / commitdiff
