@smallbook
@c %**end of header
+@c Maintenance notes:
+@c 1. Pay attention to @FIXME{}s and @UNREVISED{}s
+@c 2. Before creating final variant:
+@c 1.1. Run `make check-options' to make sure all options are properly
+@c documented;
+@c 2.1. Run `make master-menu' (see comment before the master menu).
+
@include rendition.texi
@include value.texi
+@defcodeindex op
+
@c Put everything in one index (arbitrarily chosen to be the concept index).
@syncodeindex fn cp
@syncodeindex ky cp
@syncodeindex pg cp
@syncodeindex vr cp
-@defindex op
-
@copying
This manual is for @acronym{GNU} @command{tar} (version
document. The rest of the menu lists all the lower level nodes.
@end ifnottex
-@c The master menu, created with texinfo-master-menu, goes here.
-@c (However, getdate.texi's menu is interpolated by hand.)
+@c The master menu goes here.
+@c
+@c NOTE: To update it from within Emacs, make sure mastermenu.el is
+@c loaded and run texinfo-master-menu.
+@c To update it from the command line, run
+@c
+@c make master-menu
@menu
* Introduction::
* Changes::
* Configuring Help Summary::
* Genfile::
-* Snapshot Files::
+* Tar Internals::
* Free Software Needs Free Documentation::
* Copying This Manual::
* Index of Command Line Options::
* extracting archives::
* extracting files::
* extract dir::
+* extracting untrusted archives::
* failing commands::
Invoking @GNUTAR{}
The Three Option Styles
-* Mnemonic Options:: Mnemonic Option Style
+* Long Options:: Long Option Style
* Short Options:: Short Option Style
* Old Options:: Old Option Style
* Mixing:: Mixing Option Styles
* concatenate::
* delete::
* compare::
-* quoting styles::
How to Add Files to Existing Archives: @option{--append}
* Recursive Unlink::
* Data Modification Times::
* Setting Access Permissions::
+* Directory Modification Times and Permissions::
* Writing to Standard Output::
+* Writing to an External Program::
* remove files::
Coping with Scarce Resources
* Selecting Archive Members::
* files:: Reading Names from a File
* exclude:: Excluding Some Files
-* Wildcards:: Wildcards Patterns and Matching
+* wildcards:: Wildcards Patterns and Matching
+* quoting styles:: Ways of Quoting Special Characters in Names
+* transform:: Modifying File and Member Names
* after:: Operating Only on New Files
* recurse:: Descending into Directories
* one:: Crossing File System Boundaries
* problems with exclude::
+Wildcards Patterns and Matching
+
+* controlling pattern-matching::
+
Crossing File System Boundaries
* directory:: Changing Directory
* General date syntax:: Common rules.
* Calendar date items:: 19 Dec 1994.
* Time of day items:: 9:20pm.
-* Time zone items:: @sc{est}, @sc{pdt}, @sc{gmt}, ...
+* Time zone items:: @sc{est}, @sc{pdt}, @sc{gmt}.
* Day of week items:: Monday and others.
* Relative items in date strings:: next tuesday, 2 years ago.
* Pure numbers in date strings:: 19931219, 1440.
* Seconds since the Epoch:: @@1078100502.
+* Specifying time zone rules:: TZ="America/New_York", TZ="UTC0".
* Authors of get_date:: Bellovin, Eggert, Salz, Berets, et al.
Controlling the Archive Format
* Portability:: Making @command{tar} Archives More Portable
* Compression:: Using Less Space through Compression
* Attributes:: Handling File Attributes
-* Standard:: The Standard Format
-* Extensions:: @acronym{GNU} Extensions to the Archive Format
* cpio:: Comparison of @command{tar} and @command{cpio}
Making @command{tar} Archives More Portable
* Portable Names:: Portable Names
* dereference:: Symbolic Links
* old:: Old V7 Archives
+* ustar:: Ustar Archives
+* gnu:: GNU and old GNU format archives.
* posix:: @acronym{POSIX} archives
* Checksumming:: Checksumming Problems
* Large or Negative Values:: Large files, negative time stamps, etc.
+@GNUTAR{} and @acronym{POSIX} @command{tar}
+
+* PAX keywords:: Controlling Extended Header Keywords.
+
Using Less Space through Compression
* gzip:: Creating and Reading Compressed Archives
* Tape Files:: Tape Files
* Tarcat:: Concatenate Volumes into a Single Archive
-GNU tar internals and development
-* Genfile::
+Genfile
+
+* Generate Mode:: File Generation Mode.
+* Status Mode:: File Status Mode.
+* Exec Mode:: Synchronous Execution mode.
+
+Tar Internals
+
+* Standard:: Basic Tar Format
+* Extensions:: @acronym{GNU} Extensions to the Archive Format
* Snapshot Files::
+* Dumpdir::
Copying This Manual
-* Free Software Needs Free Documentation::
* GNU Free Documentation License:: License for copying this manual
@end detailmenu
Fran@,{c}ois Pinard put version 1.11.8 of the manual together by
taking information from all these sources and merging them. Melissa
Weisshaus finally edited and redesigned the book to create version
-1.12. @FIXME{update version number as necessary; i'm being
-optimistic!} @FIXME{Someone [maybe karl berry? maybe bob chassell?
-maybe melissa? maybe julie sussman?] needs to properly index the
-thing.}
+1.12. The book for versions from 1.14 up to @value{VERSION} were edited
+by the current maintainer, Sergey Poznyakoff.
For version 1.12, Daniel Hagerty contributed a great deal of technical
consulting. In particular, he is the primary author of @ref{Backups}.
exist in @GNUTAR{} for compatibility with Unix
@command{tar}. In this book we present a full discussion of this way
of writing options and operations (@pxref{Old Options}), and we discuss
-the other two styles of writing options (@xref{Mnemonic Options}, and
+the other two styles of writing options (@xref{Long Options}, and
@pxref{Short Options}).
In the examples and in the text of this tutorial, we usually use the
@unnumberedsubsec The @option{--file} Option
@table @option
-@opindex file, tutorial
+@xopindex{file, tutorial}
@item --file=@var{archive-name}
@itemx -f @var{archive-name}
Specify the name of an archive file.
@unnumberedsubsec The @option{--verbose} Option
@table @option
-@opindex verbose, introduced
+@xopindex{verbose, introduced}
@item --verbose
@itemx -v
Show the files being worked on as @command{tar} is running.
clear, and we will give many examples both using and not using
@option{--verbose} to show the differences.
-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.}
-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
-in the former case. For example, instead of saying
+Each instance of @option{--verbose} on the command line increases the
+verbosity level by one, so if you need more details on the output,
+specify it twice.
+
+When reading archives (@option{--list}, @option{--extract},
+@option{--diff}), @command{tar} by default prints only the names of
+the members being extracted. Using @option{--verbose} will show a full,
+@command{ls} style member listing.
+
+In contrast, when writing archives (@option{--create}, @option{--append},
+@option{--update}), @command{tar} does not print file names by
+default. So, a single @option{--verbose} option shows the file names
+being added to the archive, while two @option{--verbose} options
+enable the full listing.
+
+For example, to create an archive in verbose mode:
@smallexample
-@kbd{tar -cvf afiles.tar apple angst aspic}
+$ @kbd{tar -cvf afiles.tar apple angst aspic}
+apple
+angst
+aspic
@end smallexample
@noindent
-above, you might say
+Creating the same archive with the verbosity level 2 could give:
@smallexample
-@kbd{tar -cvvf afiles.tar apple angst aspic}
+$ @kbd{tar -cvvf afiles.tar apple angst aspic}
+-rw-r--r-- gray/staff 62373 2006-06-09 12:06 apple
+-rw-r--r-- gray/staff 11481 2006-06-09 12:06 angst
+-rw-r--r-- gray/staff 23152 2006-06-09 12:06 aspic
@end smallexample
@noindent
Later in the tutorial, we will give examples using @w{@option{--verbose
--verbose}}.
+@anchor{verbose member listing}
+The full output consists of six fields:
+
+@itemize @bullet
+@item File type and permissions in symbolic form.
+These are displayed in the same format as the first column of
+@command{ls -l} output (@pxref{What information is listed,
+format=verbose, Verbose listing, fileutils, GNU file utilities}).
+
+@item Owner name and group separated by a slash character.
+If these data are not available (for example, when listing a @samp{v7} format
+archive), numeric ID values are printed instead.
+
+@item Size of the file, in bytes.
+
+@item File modification date in ISO 8601 format.
+
+@item File modification time.
+
+@item File name.
+If the name contains any special characters (white space, newlines,
+etc.) these are displayed in an unambiguous form using so called
+@dfn{quoting style}. For the detailed discussion of available styles
+and on how to use them, see @ref{quoting styles}.
+
+Depending on the file type, the name can be followed by some
+additional information, described in the following table:
+
+@table @samp
+@item -> @var{link-name}
+The file or archive member is a @dfn{symbolic link} and
+@var{link-name} is the name of file it links to.
+
+@item link to @var{link-name}
+The file or archive member is a @dfn{hard link} and @var{link-name} is
+the name of file it links to.
+
+@item --Long Link--
+The archive member is an old GNU format long link. You will normally
+not encounter this.
+
+@item --Long Name--
+The archive member is an old GNU format long name. You will normally
+not encounter this.
+
+@item --Volume Header--
+The archive member is a GNU @dfn{volume header} (@pxref{Tape Files}).
+
+@item --Continued at byte @var{n}--
+Encountered only at the beginning of a multy-volume archive
+(@pxref{Using Multiple Tapes}). This archive member is a continuation
+from the previous volume. The number @var{n} gives the offset where
+the original file was split.
+
+@item --Mangled file names--
+This archive member contains @dfn{mangled file names} declarations,
+a special member type that was used by early versions of @GNUTAR{}.
+You probably will never encounter this, unless you are reading a very
+old archive.
+
+@item unknown file type @var{c}
+An archive member of unknown type. @var{c} is the type character from
+the archive header. If you encounter such a message, it means that
+either your archive contains proprietary member types @GNUTAR{} is not
+able to handle, or the archive is corrupted.
+@end table
+
+@end itemize
+
+For example, here is an archive listing containing most of the special
+suffixes explained above:
+
+@smallexample
+@group
+V--------- 0/0 1536 2006-06-09 13:07 MyVolume--Volume Header--
+-rw-r--r-- gray/staff 456783 2006-06-09 12:06 aspic--Continued at
+byte 32456--
+-rw-r--r-- gray/staff 62373 2006-06-09 12:06 apple
+lrwxrwxrwx gray/staff 0 2006-06-09 13:01 angst -> apple
+-rw-r--r-- gray/staff 35793 2006-06-09 12:06 blues
+hrw-r--r-- gray/staff 0 2006-06-09 12:06 music link to blues
+@end group
+@end smallexample
+
+@smallexample
+@end smallexample
+
@node help tutorial
@unnumberedsubsec Getting Help: Using the @option{--help} Option
@node Creating the archive
@subsection Creating the Archive
-@opindex create, introduced
+@xopindex{create, introduced}
To place the files @file{blues}, @file{folk}, and @file{jazz} into an
archive named @file{collection.tar}, use the following command:
@command{tar}, to avoid errors).
Note that the part of the command which says,
-@w{@option{--file=collection.tar}} is considered to be @emph{one} argument.
+@option{--file=@-collection.tar} is considered to be @emph{one} argument.
If you substituted any other string of characters for
@kbd{collection.tar}, then that string would become the name of the
archive file you create.
(@file{collection.tar}), and @option{--file} is the option which lets
you give it the name you chose. The files, @file{blues}, @file{folk},
and @file{jazz}, are now members of the archive, @file{collection.tar}
-(they are @dfn{file name arguments} to the @option{--create} operation).
-@FIXME{xref here to the discussion of file name args?}Now that they are
+(they are @dfn{file name arguments} to the @option{--create} operation.
+@xref{Choosing}, for the detailed discussion on these.) Now that they are
in the archive, they are called @emph{archive members}, not files.
(@pxref{Definitions,members}).
@node create verbose
@subsection Running @option{--create} with @option{--verbose}
-@opindex create, using with @option{--verbose}
-@opindex verbose, using with @option{--create}
+@xopindex{create, using with @option{--verbose}}
+@xopindex{verbose, using with @option{--create}}
If you include the @option{--verbose} (@option{-v}) option on the command line,
@command{tar} will list the files it is acting on as it is working. In
verbose mode, the @code{create} example above would appear as:
@opindex list
Frequently, you will find yourself wanting to determine exactly what a
-particular archive contains. You can use the @option{--list} (@option{-t}) operation
-to get the member names as they currently appear in the archive, as well
-as various attributes of the files at the time they were archived. For
-example, you can examine the archive @file{collection.tar} that you
-created in the last section with the command,
+particular archive contains. You can use the @option{--list}
+(@option{-t}) operation to get the member names as they currently
+appear in the archive, as well as various attributes of the files at
+the time they were archived. For example, you can examine the archive
+@file{collection.tar} that you created in the last section with the
+command,
@smallexample
$ @kbd{tar --list --file=collection.tar}
@var{archive-name}}) option just as with @option{--create}
(@option{-c}) to specify the name of the archive.
-@opindex list, using with @option{--verbose}
-@opindex verbose, using with @option{--list}
+@xopindex{list, using with @option{--verbose}}
+@xopindex{verbose, using with @option{--list}}
If you use the @option{--verbose} (@option{-v}) option with
@option{--list}, then @command{tar} will print out a listing
-reminiscent of @w{@samp{ls -l}}, showing owner, file size, and so forth.
+reminiscent of @w{@samp{ls -l}}, showing owner, file size, and so
+forth. This output is described in detail in @ref{verbose member listing}.
If you had used @option{--verbose} (@option{-v}) mode, the example
above would look like:
@end table
@cindex File name arguments, using @option{--list} with
-@opindex list, using with file name arguments
+@xopindex{list, using with file name arguments}
You can specify one or more individual member names as arguments when
using @samp{list}. In this case, @command{tar} will only list the
names of members you identify. For example, @w{@kbd{tar --list
--file=afiles.tar apple}} would only print @file{apple}.
Because @command{tar} preserves paths, file names must be specified as
-they appear in the archive (ie., relative to the directory from which
+they appear in the archive (i.e., relative to the directory from which
the archive was created). Therefore, it is essential when specifying
member names to @command{tar} that you give the exact member names.
For example, @w{@kbd{tar --list --file=bfiles.tar birds}} would produce an
@end smallexample
@noindent
-will list all members whose name contains @samp{b}. @xref{Wildcards},
+will list all members whose name contains @samp{b}. @xref{wildcards},
for a detailed discussion of globbing patterns and related
@command{tar} command line options.
command line arguments as globbing patterns and @option{--no-anchored}
informs it that the patterns apply to member names after any @samp{/}
delimiter. The use of globbing patterns is discussed in detail in
-@xref{Wildcards}.
+@xref{wildcards}.
You can extract a file to standard output by combining the above options
with the @option{--to-stdout} (@option{-O}) option (@pxref{Writing to Standard
The distinction between file names and archive member names is especially
important when shell globbing is used, and sometimes a source of confusion
-for newcomers. @xref{Wildcards}, for more information about globbing.
+for newcomers. @xref{wildcards}, for more information about globbing.
The problem is that shells may only glob using existing files in the
file system. Only @command{tar} itself may glob on archive members, so when
needed, you must ensure that wildcard characters reach @command{tar} without
pay special attention to them.
@menu
-* Mnemonic Options:: Mnemonic Option Style
+* Long Options:: Long Option Style
* Short Options:: Short Option Style
* Old Options:: Old Option Style
* Mixing:: Mixing Option Styles
@end menu
-@node Mnemonic Options
-@subsection Mnemonic Option Style
-
-@FIXME{have to decide whether or not to replace other occurrences of
-"mnemonic" with "long", or *ugh* vice versa.}
+@node Long Options
+@subsection Long Option Style
-Each option has at least one long (or mnemonic) name starting with two
+Each option has at least one @dfn{long} (or @dfn{mnemonic}) name starting with two
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
+single long option has many different different names which are
synonymous, such as @option{--compare} and @option{--diff}. In addition,
long option names can be given unique abbreviations. For example,
@option{--cre} can be used in place of @option{--create} because there is no
-other mnemonic option which begins with @samp{cre}. (One way to find
+other long option which begins with @samp{cre}. (One way to find
this out is by trying it and seeing what happens; if a particular
abbreviation could represent more than one option, @command{tar} will tell
you that that abbreviation is ambiguous and you'll know that that
unique abbreviation for the long name of an option you didn't want to
use, you are stuck; @command{tar} will perform the command as ordered.)
-Mnemonic options are meant to be obvious and easy to remember, and their
+Long options are meant to be obvious and easy to remember, and their
meanings are generally easier to discern than those of their
corresponding short options (see below). For example:
gives a fairly good set of hints about what the command does, even
for those not fully acquainted with @command{tar}.
-Mnemonic options which require arguments take those arguments
+Long 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
option name either by an equal sign, or by any amount of
@node Short Options
@subsection Short Option Style
-Most options also have a short option name. Short options start with
+Most options also have a @dfn{short option} name. Short options start with
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.
@subsection Old Option Style
@UNREVISED
-Like short options, old options are single letters. However, old options
+Like short options, @dfn{old options} are single letters. However, old options
must be written together as a single clumped set, without spaces separating
them or dashes preceding them@footnote{Beware that if you precede options
with a dash, you are announcing the short option style instead of the
anywhere else. The letter of an old option is exactly the same letter as
the corresponding short option. For example, the old option @samp{t} is
the same as the short option @option{-t}, and consequently, the same as the
-mnemonic option @option{--list}. So for example, the command @w{@samp{tar
+long option @option{--list}. So for example, the command @w{@samp{tar
cv}} specifies the option @option{-v} in addition to the operation @option{-c}.
When options that need arguments are given together with the command,
All three styles may be intermixed in a single @command{tar} command,
so long as the rules for each style are fully
respected@footnote{Before @GNUTAR{} version 1.11.6,
-a bug prevented intermixing old style options with mnemonic options in
+a bug prevented intermixing old style options with long options in
some cases.}. Old style options and either of the modern styles of
options may be mixed within a single @command{tar} command. However,
old style options must be introduced as the first arguments only,
@table @option
-@opindex append, summary
+@opsummary{append}
@item --append
@itemx -r
Appends files to the end of the archive. @xref{append}.
-@opindex catenate, summary
+@opsummary{catenate}
@item --catenate
@itemx -A
Same as @option{--concatenate}. @xref{concatenate}.
-@opindex compare, summary
+@opsummary{compare}
@item --compare
@itemx -d
system, and reports differences in file size, mode, owner,
modification date and contents. @xref{compare}.
-@opindex concatenate, summary
+@opsummary{concatenate}
@item --concatenate
@itemx -A
Appends other @command{tar} archives to the end of the archive.
@xref{concatenate}.
-@opindex create, summary
+@opsummary{create}
@item --create
@itemx -c
Creates a new @command{tar} archive. @xref{create}.
-@opindex delete, summary
+@opsummary{delete}
@item --delete
Deletes members from the archive. Don't try this on a archive on a
tape! @xref{delete}.
-@opindex diff, summary
+@opsummary{diff}
@item --diff
@itemx -d
Same @option{--compare}. @xref{compare}.
-@opindex extract, summary
+@opsummary{extract}
@item --extract
@itemx -x
Extracts members from the archive into the file system. @xref{extract}.
-@opindex get, summary
+@opsummary{get}
@item --get
@itemx -x
Same as @option{--extract}. @xref{extract}.
-@opindex list, summary
+@opsummary{list}
@item --list
@itemx -t
Lists the members in an archive. @xref{list}.
-@opindex update, summary
+@opsummary{update}
@item --update
@itemx -u
@table @option
-@opindex absolute-names, summary
+@opsummary{absolute-names}
@item --absolute-names
@itemx -P
@samp{/} from member names. This option disables that behavior.
@xref{absolute}.
-@opindex after-date, summary
+@opsummary{after-date}
@item --after-date
(See @option{--newer}, @pxref{after})
-@opindex anchored, summary
+@opsummary{anchored}
@item --anchored
A pattern must match an initial subsequence of the name's components.
@xref{controlling pattern-matching}.
-@opindex atime-preserve, summary
+@opsummary{atime-preserve}
@item --atime-preserve
@itemx --atime-preserve=replace
@itemx --atime-preserve=system
as support for @option{--atime-preserve=system} improves.
If your operating system does not support
-@option{--atime-preserve=system}, you might be able to preserve access
+@option{--atime-preserve=@-system}, you might be able to preserve access
times reliably by by using the @command{mount} command. For example,
you can mount the file system read-only, or access the file system via
a read-only loopback mount, or use the @samp{noatime} mount option
available on some systems. However, mounting typically requires
superuser privileges and can be a pain to manage.
-@opindex backup, summary
+@opsummary{backup}
@item --backup=@var{backup-type}
Rather than deleting files from the file system, @command{tar} will
back them up using simple or numbered backups, depending upon
@var{backup-type}. @xref{backup}.
-@opindex block-number, summary
+@opsummary{block-number}
@item --block-number
@itemx -R
With this option present, @command{tar} prints error messages for read errors
with the block number in the archive file. @xref{block-number}.
-@opindex blocking-factor, summary
+@opsummary{blocking-factor}
@item --blocking-factor=@var{blocking}
@itemx -b @var{blocking}
Sets the blocking factor @command{tar} uses to @var{blocking} x 512 bytes per
record. @xref{Blocking Factor}.
-@opindex bzip2, summary
+@opsummary{bzip2}
@item --bzip2
@itemx -j
This option tells @command{tar} to read or write archives through
@code{bzip2}. @xref{gzip}.
-@opindex checkpoint, summary
-@item --checkpoint
+@opsummary{checkpoint}
+@item --checkpoint[=@var{number}]
-This option directs @command{tar} to print periodic checkpoint messages as it
-reads through the archive. It is intended for when you want a visual
-indication that @command{tar} is still running, but don't want to see
-@option{--verbose} output. @FIXME-xref{}
+This option directs @command{tar} to print periodic checkpoint
+messages as it reads through the archive. It is intended for when you
+want a visual indication that @command{tar} is still running, but
+don't want to see @option{--verbose} output. For a detailed
+description, see @ref{Progress information}.
-@opindex check-links, summary
+@opsummary{check-links}
@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
total number of hard links for the file, a warning message will be
output @footnote{Earlier versions of @GNUTAR{} understood @option{-l} as a
-synonym for @option{--one-file-system}. The current semantics, wich
+synonym for @option{--one-file-system}. The current semantics, which
complies to UNIX98, was introduced with version
1.15.91. @xref{Changes}, for more information.}.
-@opindex compress, summary
-@opindex uncompress, summary
+@opsummary{compress}
+@opsummary{uncompress}
@item --compress
@itemx --uncompress
@itemx -Z
writing the archive. This allows you to directly act on archives
while saving space. @xref{gzip}.
-@opindex confirmation, summary
+@opsummary{confirmation}
@item --confirmation
(See @option{--interactive}.) @xref{interactive}.
-@opindex delay-directory-restore, summary
+@opsummary{delay-directory-restore}
@item --delay-directory-restore
Delay setting modification times and permissions of extracted
directories until the end of extraction. @xref{Directory Modification Times and Permissions}.
-@opindex dereference, summary
+@opsummary{dereference}
@item --dereference
@itemx -h
file that a symbolic link points to, rather than archiving the
symlink. @xref{dereference}.
-@opindex directory, summary
+@opsummary{directory}
@item --directory=@var{dir}
@itemx -C @var{dir}
to @var{dir} before performing any operations. When this option is used
during archive creation, it is order sensitive. @xref{directory}.
-@opindex exclude, summary
+@opsummary{exclude}
@item --exclude=@var{pattern}
When performing operations, @command{tar} will skip files that match
@var{pattern}. @xref{exclude}.
-@opindex exclude-from, summary
+@opsummary{exclude-from}
@item --exclude-from=@var{file}
@itemx -X @var{file}
Similar to @option{--exclude}, except @command{tar} will use the list of
patterns in the file @var{file}. @xref{exclude}.
-@opindex exclude-caches, summary
+@opsummary{exclude-caches}
@item --exclude-caches
Automatically excludes all directories
containing a cache directory tag. @xref{exclude}.
-@opindex file, summary
+@opsummary{file}
@item --file=@var{archive}
@itemx -f @var{archive}
performs operations on, rather than @command{tar}'s compilation dependent
default. @xref{file tutorial}.
-@opindex files-from, summary
+@opsummary{files-from}
@item --files-from=@var{file}
@itemx -T @var{file}
or files to operate on, in addition to those specified on the
command-line. @xref{files}.
-@opindex force-local, summary
+@opsummary{force-local}
@item --force-local
Forces @command{tar} to interpret the filename given to @option{--file}
as a local file, even if it looks like a remote tape drive name.
@xref{local and remote archives}.
-@opindex format, summary
+@opsummary{format}
@item --format=@var{format}
+@itemx -H @var{format}
Selects output archive format. @var{Format} may be one of the
following:
@xref{Formats}, for a detailed discussion of these formats.
-@opindex group, summary
+@opsummary{group}
@item --group=@var{group}
Files added to the @command{tar} archive will have a group id of @var{group},
Also see the comments for the @option{--owner=@var{user}} option.
-@opindex gzip, summary
-@opindex gunzip, summary
-@opindex ungzip, summary
+@opsummary{gzip}
+@opsummary{gunzip}
+@opsummary{ungzip}
@item --gzip
@itemx --gunzip
@itemx --ungzip
@command{gzip}, allowing @command{tar} to directly operate on several
kinds of compressed archives transparently. @xref{gzip}.
-@opindex help, summary
+@opsummary{help}
@item --help
+@itemx -?
@command{tar} will print out a short message summarizing the operations and
options to @command{tar} and exit. @xref{help}.
-@opindex ignore-case, summary
+@opsummary{ignore-case}
@item --ignore-case
Ignore case when matching member or file names with
patterns. @xref{controlling pattern-matching}.
-@opindex ignore-command-error, summary
+@opsummary{ignore-command-error}
@item --ignore-command-error
Ignore exit codes of subprocesses. @xref{Writing to an External Program}.
-@opindex ignore-failed-read, summary
+@opsummary{ignore-failed-read}
@item --ignore-failed-read
Do not exit unsuccessfully merely because an unreadable file was encountered.
@xref{Reading}.
-@opindex ignore-zeros, summary
+@opsummary{ignore-zeros}
@item --ignore-zeros
@itemx -i
With this option, @command{tar} will ignore zeroed blocks in the
archive, which normally signals EOF. @xref{Reading}.
-@opindex incremental, summary
+@opsummary{incremental}
@item --incremental
@itemx -G
primarily for backwards compatibility only. @xref{Incremental Dumps},
for a detailed discussion of incremental archives.
-@opindex index-file, summary
+@opsummary{index-file}
@item --index-file=@var{file}
Send verbose output to @var{file} instead of to standard output.
-@opindex info-script, summary
-@opindex new-volume-script, summary
+@opsummary{info-script}
+@opsummary{new-volume-script}
@item --info-script=@var{script-file}
@itemx --new-volume-script=@var{script-file}
@itemx -F @var{script-file}
@command{tar} fails immediately. @xref{info-script}, for a detailed
discussion of @var{script-file}.
-@opindex interactive, summary
+@opsummary{interactive}
@item --interactive
@itemx --confirmation
@itemx -w
performing potentially destructive options, such as overwriting files.
@xref{interactive}.
-@opindex keep-newer-files, summary
+@opsummary{keep-newer-files}
@item --keep-newer-files
Do not replace existing files that are newer than their archive copies
when extracting files from an archive.
-@opindex keep-old-files, summary
+@opsummary{keep-old-files}
@item --keep-old-files
@itemx -k
Do not overwrite existing files when extracting files from an archive.
@xref{Keep Old Files}.
-@opindex label, summary
+@opsummary{label}
@item --label=@var{name}
@itemx -V @var{name}
@command{tar} will only operate on archives that have a label matching
the pattern specified in @var{name}. @xref{Tape Files}.
-@opindex listed-incremental, summary
+@opsummary{listed-incremental}
@item --listed-incremental=@var{snapshot-file}
@itemx -g @var{snapshot-file}
With other operations, informs @command{tar} that the archive is in
incremental format. @xref{Incremental Dumps}.
-@opindex mode, summary
+@opsummary{mode}
@item --mode=@var{permissions}
When adding files to an archive, @command{tar} will use
permissions for everybody, while retaining executable bits on directories
or on any other file already marked as executable.
-@opindex multi-volume, summary
+@opsummary{multi-volume}
@item --multi-volume
@itemx -M
Informs @command{tar} that it should create or otherwise operate on a
multi-volume @command{tar} archive. @xref{Using Multiple Tapes}.
-@opindex new-volume-script, summary
+@opsummary{new-volume-script}
@item --new-volume-script
(see --info-script)
-@opindex seek, summary
+@opsummary{seek}
@item --seek
@itemx -n
the archive can be seeked or not. This option is intended for use
in cases when such recognition fails.
-@opindex newer, summary
+@opsummary{newer}
@item --newer=@var{date}
@itemx --after-date=@var{date}
@itemx -N
is taken to be the name of a file whose data modification time specifies
the date. @xref{after}.
-@opindex newer-mtime, summary
+@opsummary{newer-mtime}
@item --newer-mtime=@var{date}
Like @option{--newer}, but add only files whose
contents have changed (as opposed to just @option{--newer}, which will
also back up files for which any status information has changed).
-@opindex no-anchored, summary
+@opsummary{no-anchored}
@item --no-anchored
An exclude pattern can match any subsequence of the name's components.
@xref{controlling pattern-matching}.
-@opindex no-delay-directory-restore, summary
+@opsummary{no-delay-directory-restore}
@item --no-delay-directory-restore
Setting modification times and permissions of extracted
directories when all files from this directory has been
extracted. This is the default. @xref{Directory Modification Times and Permissions}.
-@opindex no-ignore-case, summary
+@opsummary{no-ignore-case}
@item --no-ignore-case
Use case-sensitive matching.
@xref{controlling pattern-matching}.
-@opindex no-ignore-command-error, summary
+@opsummary{no-ignore-command-error}
@item --no-ignore-command-error
Print warnings about subprocesses terminated with a non-zero exit
code. @xref{Writing to an External Program}.
-@opindex no-quote-chars, summary
+@opsummary{no-overwrite-dir}
+@item --no-overwrite-dir
+
+Preserve metadata of existing directories when extracting files
+from an archive. @xref{Overwrite Old Files}.
+
+@opsummary{no-quote-chars}
@item --no-quote-chars=@var{string}
Remove characters listed in @var{string} from the list of quoted
characters set by the previous @option{--quote-chars} option
(@pxref{quoting styles}).
-@opindex no-recursion, summary
+@opsummary{no-recursion}
@item --no-recursion
With this option, @command{tar} will not recurse into directories.
@xref{recurse}.
-@opindex no-same-owner, summary
+@opsummary{no-same-owner}
@item --no-same-owner
@itemx -o
specified in the @command{tar} archive. This the default behavior
for ordinary users.
-@opindex no-same-permissions, summary
+@opsummary{no-same-permissions}
@item --no-same-permissions
When extracting an archive, subtract the user's umask from files from
the permissions specified in the archive. This is the default behavior
for ordinary users.
-@opindex no-wildcards, summary
+@opsummary{no-unquote}
+@item --no-unquote
+Treat all input file or member names literally, do not interpret
+escape sequences. @xref{input name quoting}.
+
+@opsummary{no-wildcards}
@item --no-wildcards
Do not use wildcards.
@xref{controlling pattern-matching}.
-@opindex no-wildcards-match-slash, summary
+@opsummary{no-wildcards-match-slash}
@item --no-wildcards-match-slash
Wildcards do not match @samp{/}.
@xref{controlling pattern-matching}.
-@opindex null, summary
+@opsummary{null}
@item --null
When @command{tar} is using the @option{--files-from} option, this option
@command{tar} can correctly work with file names that contain newlines.
@xref{nul}.
-@opindex numeric-owner, summary
+@opsummary{numeric-owner}
@item --numeric-owner
This option will notify @command{tar} that it should use numeric user
@xref{Changes}, for more information.
-@opindex occurrence, summary
+@opsummary{occurrence}
@item --occurrence[=@var{number}]
This option can be used in conjunction with one of the subcommands
will extract the first occurrence of @file{filename} from @file{archive.tar}
and will terminate without scanning to the end of the archive.
-@opindex old-archive, summary
+@opsummary{old-archive}
@item --old-archive
Synonym for @option{--format=v7}.
-@opindex one-file-system, summary
+@opsummary{one-file-system}
@item --one-file-system
Used when creating an archive. Prevents @command{tar} from recursing into
directories that are on different file systems from the current
synonym for @option{--one-file-system}. This has changed in version
1.15.91. @xref{Changes}, for more information.}.
-@opindex overwrite, summary
+@opsummary{overwrite}
@item --overwrite
Overwrite existing files and directory metadata when extracting files
from an archive. @xref{Overwrite Old Files}.
-@opindex overwrite-dir, summary
+@opsummary{overwrite-dir}
@item --overwrite-dir
Overwrite the metadata of existing directories when extracting files
from an archive. @xref{Overwrite Old Files}.
-@opindex owner, summary
+@opsummary{owner}
@item --owner=@var{user}
Specifies that @command{tar} should use @var{user} as the owner of members
This option does not affect extraction from archives.
-@opindex transform, summary
+@opsummary{transform}
@item --transform=@var{sed-expr}
Transform file or member names using @command{sed} replacement expression
@noindent
will add to @file{archive} files from the current working directory,
replacing initial @samp{./} prefix with @samp{usr/}. For the detailed
-discussion, see @FIXME-xref{transform}
+discussion, @xref{transform}.
To see transformed member names in verbose listings, use
@option{--show-transformed-names} option
-(@FIXME-pxref{show-transformed-names}).
+(@pxref{show-transformed-names}).
-@opindex quote-chars, summary
+@opsummary{quote-chars}
@item --quote-chars=@var{string}
Always quote characters from @var{string}, even if the selected
quoting style would not quote them (@pxref{quoting styles}).
-@opindex quoting-style, summary
+@opsummary{quoting-style}
@item --quoting-style=@var{style}
Set quoting style to use when printing member and file names
(@pxref{quoting styles}). Valid @var{style} values are:
style is @code{escape}, unless overridden while configuring the
package.
-@opindex pax-option, summary
+@opsummary{pax-option}
@item --pax-option=@var{keyword-list}
-@FIXME{Such a detailed description does not belong there, move it elsewhere.}
This option is meaningful only with @acronym{POSIX.1-2001} archives
(@pxref{posix}). 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:
-
-@table @asis
-@item delete=@var{pattern}
-When used with one of archive-creation commands,
-this option instructs @command{tar} to omit from extended header records
-that it produces any keywords matching the string @var{pattern}.
-
-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
-matching notation described in @acronym{POSIX 1003.2}, 3.13
-(See @cite{glob(7)}). For example:
-
-@smallexample
---pax-option delete=security.*
-@end smallexample
-
-would suppress security-related information.
-
-@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
-from @var{string} after making the following substitutions:
-
-@multitable @columnfractions .30 .70
-@headitem Meta-character @tab Replaced By
-@item %d @tab The directory name of the file, equivalent to the
-result of the @command{dirname} utility on the translated pathname.
-@item %f @tab The filename of the file, equivalent to the result
-of the @command{basename} utility on the translated pathname.
-@item %p @tab The process ID of the @command{tar} process.
-@item %% @tab A @samp{%} character.
-@end multitable
-
-Any other @samp{%} characters in @var{string} produce undefined
-results.
-
-If no option @samp{exthdr.name=string} is specified, @command{tar}
-will use the following default value:
-
-@smallexample
-%d/PaxHeaders.%p/%f
-@end smallexample
-
-@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
-is obtained from the contents of @var{string}, after making
-the following substitutions:
-
-@multitable @columnfractions .30 .70
-@headitem Meta-character @tab Replaced By
-@item %n @tab An integer that represents the
-sequence number of the global extended header record in the archive,
-starting at 1.
-@item %p @tab The process ID of the @command{tar} process.
-@item %% @tab A @samp{%} character.
-@end multitable
-
-Any other @samp{%} characters in @var{string} produce undefined results.
-
-If no option @samp{globexthdr.name=string} is specified, @command{tar}
-will use the following default value:
-
-@smallexample
-$TMPDIR/GlobalHead.%p.%n
-@end smallexample
-
-@noindent
-where @samp{$TMPDIR} represents the value of the @var{TMPDIR}
-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,
-@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}
-form except that it creates no global extended header records.
-
-When used with one of archive-reading commands, @command{tar} will
-behave as if these keyword/value pairs were included as records at the
-end of each extended header; thus, they will override any global or
-file-specific extended header record keywords of the same names.
-For example, in the command:
-
-@smallexample
-tar --format=posix --create \
- --file archive --pax-option gname:=user .
-@end smallexample
-
-the group name will be forced to a new value for all files
-stored in the archive.
-@end table
+list of keyword options. @xref{PAX keywords}, for a detailed
+discussion.
-@opindex portability, summary
+@opsummary{portability}
@item --portability
@itemx --old-archive
Synonym for @option{--format=v7}.
-@opindex posix, summary
+@opsummary{posix}
@item --posix
Same as @option{--format=posix}.
-@opindex preserve, summary
+@opsummary{preserve}
@item --preserve
Synonymous with specifying both @option{--preserve-permissions} and
@option{--same-order}. @xref{Setting Access Permissions}.
-@opindex preserve-order, summary
+@opsummary{preserve-order}
@item --preserve-order
(See @option{--same-order}; @pxref{Reading}.)
-@opindex preserve-permissions, summary
-@opindex same-permissions, summary
+@opsummary{preserve-permissions}
+@opsummary{same-permissions}
@item --preserve-permissions
@itemx --same-permissions
@itemx -p
Specifying this option instructs @command{tar} that it should use the
permissions directly from the archive. @xref{Setting Access Permissions}.
-@opindex read-full-records, summary
+@opsummary{read-full-records}
@item --read-full-records
@itemx -B
Specifies that @command{tar} should reblock its input, for reading
from pipes on systems with buggy implementations. @xref{Reading}.
-@opindex record-size, summary
+@opsummary{record-size}
@item --record-size=@var{size}
Instructs @command{tar} to use @var{size} bytes per record when accessing the
archive. @xref{Blocking Factor}.
-@opindex recursion, summary
+@opsummary{recursion}
@item --recursion
With this option, @command{tar} recurses into directories.
@xref{recurse}.
-@opindex recursive-unlink, summary
+@opsummary{recursive-unlink}
@item --recursive-unlink
Remove existing
directory hierarchies before extracting directories of the same name
from the archive. @xref{Recursive Unlink}.
-@opindex remove-files, summary
+@opsummary{remove-files}
@item --remove-files
Directs @command{tar} to remove the source file from the file system after
appending it to an archive. @xref{remove files}.
-@opindex restrict, summary
+@opsummary{restrict}
@item --restrict
Disable use of some potentially harmful @command{tar} options.
Currently this option disables shell invocaton from multi-volume menu
(@pxref{Using Multiple Tapes}).
-@opindex rmt-command, summary
+@opsummary{rmt-command}
@item --rmt-command=@var{cmd}
Notifies @command{tar} that it should use @var{cmd} instead of
the default @file{/usr/libexec/rmt} (@pxref{Remote Tape Server}).
-@opindex rsh-command, summary
+@opsummary{rsh-command}
@item --rsh-command=@var{cmd}
Notifies @command{tar} that is should use @var{cmd} to communicate with remote
devices. @xref{Device}.
-@opindex same-order, summary
+@opsummary{same-order}
@item --same-order
@itemx --preserve-order
@itemx -s
arguments has already been sorted to match the order of files in the
archive. @xref{Reading}.
-@opindex same-owner, summary
+@opsummary{same-owner}
@item --same-owner
When extracting an archive, @command{tar} will attempt to preserve the owner
This is the default behavior for the superuser; this option has an
effect only for ordinary users. @xref{Attributes}.
-@opindex same-permissions, summary
+@opsummary{same-permissions}
@item --same-permissions
(See @option{--preserve-permissions}; @pxref{Setting Access Permissions}.)
-@opindex show-defaults, summary
+@opsummary{show-defaults}
@item --show-defaults
Displays the default options used by @command{tar} and exits
--rmt-command=/usr/libexec/rmt --rsh-command=/usr/bin/rsh
@end smallexample
-@opindex show-omitted-dirs, summary
+@opsummary{show-omitted-dirs}
@item --show-omitted-dirs
Instructs @command{tar} to mention directories its skipping over when
operating on a @command{tar} archive. @xref{show-omitted-dirs}.
-@opindex show-transformed-names, summary
-@opindex show-stored-names, summary
+@opsummary{show-transformed-names}
+@opsummary{show-stored-names}
@item --show-transformed-names
@itemx --show-stored-names
Display file or member names after applying any transformations
-(@FIXME-pxref{}). In particular, when used in conjunction with one of
+(@pxref{transform}). In particular, when used in conjunction with one of
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}.
-@opindex sparse, summary
+@opsummary{sparse}
@item --sparse
@itemx -S
Invokes a @acronym{GNU} extension when adding files to an archive that handles
sparse files efficiently. @xref{sparse}.
-@opindex starting-file, summary
+@opsummary{starting-file}
@item --starting-file=@var{name}
@itemx -K @var{name}
files in the archive until it finds one that matches @var{name}.
@xref{Scarce}.
-@opindex strip-components, summary
+@opsummary{strip-components}
@item --strip-components=@var{number}
Strip given @var{number} of leading components from file names before
extraction.@footnote{This option was called @option{--strip-path} in
@end smallexample
@noindent
-would extracted this file to file @file{name}.
+would extract this file to file @file{name}.
-@opindex suffix, summary
+@opsummary{suffix}, summary
@item --suffix=@var{suffix}
Alters the suffix @command{tar} uses when backing up files from the default
@samp{~}. @xref{backup}.
-@opindex tape-length, summary
+@opsummary{tape-length}
@item --tape-length=@var{num}
@itemx -L @var{num}
Specifies the length of tapes that @command{tar} is writing as being
@w{@var{num} x 1024} bytes long. @xref{Using Multiple Tapes}.
-@opindex test-label, summary
+@opsummary{test-label}
@item --test-label
Reads the volume label. If an argument is specified, test whether it
matches the volume label. @xref{--test-label option}.
-@opindex to-command, summary
+@opsummary{to-command}
@item --to-command=@var{command}
During extraction @command{tar} will pipe extracted files to the
-standard input of @var{command}. @xref{Writing to an External Program}.
+standard input of @var{command}. @xref{Writing to an External Program}.
-@opindex to-stdout, summary
+@opsummary{to-stdout}
@item --to-stdout
@itemx -O
During extraction, @command{tar} will extract files to stdout rather
than to the file system. @xref{Writing to Standard Output}.
-@opindex totals, summary
-@item --totals
+@opsummary{totals}
+@item --totals[=@var{signo}]
-Displays the total number of bytes written after creating an archive.
-@xref{verbose}.
+Displays the total number of bytes transferred when processing an
+archive. If an argument is given, these data are displayed on
+request, when signal @var{signo} is delivered to @command{tar}.
+@xref{totals}.
-@opindex touch, summary
+@opsummary{touch}
@item --touch
@itemx -m
rather than the data modification time stored in the archive.
@xref{Data Modification Times}.
-@opindex uncompress, summary
+@opsummary{uncompress}
@item --uncompress
(See @option{--compress}. @pxref{gzip})
-@opindex ungzip, summary
+@opsummary{ungzip}
@item --ungzip
(See @option{--gzip}. @pxref{gzip})
-@opindex unlink-first, summary
+@opsummary{unlink-first}
@item --unlink-first
@itemx -U
Directs @command{tar} to remove the corresponding file from the file
system before extracting it from the archive. @xref{Unlink First}.
-@opindex use-compress-program, summary
+@opsummary{unquote}
+@item --unquote
+Enable unquoting input file or member names (default). @xref{input
+name quoting}.
+
+@opsummary{use-compress-program}
@item --use-compress-program=@var{prog}
Instructs @command{tar} to access the archive through @var{prog}, which is
presumed to be a compression program of some sort. @xref{gzip}.
-@opindex utc, summary
+@opsummary{utc}
@item --utc
Display file modification dates in @acronym{UTC}. This option implies
@option{--verbose}.
-@opindex verbose, summary
+@opsummary{verbose}
@item --verbose
@itemx -v
operations to increase the amount of information displayed.
@xref{verbose}.
-@opindex verify, summary
+@opsummary{verify}
@item --verify
@itemx -W
Verifies that the archive was correctly written when creating an
archive. @xref{verify}.
-@opindex version, summary
+@opsummary{version}
@item --version
Print information about the program's name, version, origin and legal
status, all on standard output, and then exit successfully.
@xref{help}.
-@opindex volno-file, summary
+@opsummary{volno-file}
@item --volno-file=@var{file}
-Used in conjunction with @option{--multi-volume}. @command{tar} will keep track
-of which volume of a multi-volume archive its working in @var{file}.
-@xref{volno-file}.
+Used in conjunction with @option{--multi-volume}. @command{tar} will
+keep track of which volume of a multi-volume archive its working in
+@var{file}. @xref{volno-file}.
-@opindex wildcards, summary
+@opsummary{wildcards}
@item --wildcards
Use wildcards when matching member names with patterns.
@xref{controlling pattern-matching}.
-@opindex wildcards-match-slash, summary
+@opsummary{wildcards-match-slash}
@item --wildcards-match-slash
Wildcards match @samp{/}.
@xref{controlling pattern-matching}.
Here is an alphabetized list of all of the short option forms, matching
them with the equivalent long option.
-@table @option
-
-@item -A
-
-@option{--concatenate}
-
-@item -B
-
-@option{--read-full-records}
-
-@item -C
+@multitable @columnfractions 0.20 0.80
+@headitem Short Option @tab Reference
-@option{--directory}
+@item -A @tab @ref{--concatenate}.
-@item -F
+@item -B @tab @ref{--read-full-records}.
-@option{--info-script}
+@item -C @tab @ref{--directory}.
-@item -G
+@item -F @tab @ref{--info-script}.
-@option{--incremental}
-
-@item -K
-
-@option{--starting-file}
-
-@item -L
-
-@option{--tape-length}
-
-@item -M
-
-@option{--multi-volume}
-
-@item -N
-
-@option{--newer}
-
-@item -O
-
-@option{--to-stdout}
-
-@item -P
-
-@option{--absolute-names}
-
-@item -R
-
-@option{--block-number}
-
-@item -S
-
-@option{--sparse}
-
-@item -T
-
-@option{--files-from}
-
-@item -U
-
-@option{--unlink-first}
-
-@item -V
-
-@option{--label}
-
-@item -W
-
-@option{--verify}
-
-@item -X
-
-@option{--exclude-from}
-
-@item -Z
+@item -G @tab @ref{--incremental}.
-@option{--compress}
+@item -K @tab @ref{--starting-file}.
-@item -b
+@item -L @tab @ref{--tape-length}.
-@option{--blocking-factor}
+@item -M @tab @ref{--multi-volume}.
-@item -c
+@item -N @tab @ref{--newer}.
-@option{--create}
+@item -O @tab @ref{--to-stdout}.
-@item -d
+@item -P @tab @ref{--absolute-names}.
-@option{--compare}
+@item -R @tab @ref{--block-number}.
-@item -f
+@item -S @tab @ref{--sparse}.
-@option{--file}
+@item -T @tab @ref{--files-from}.
-@item -g
+@item -U @tab @ref{--unlink-first}.
-@option{--listed-incremental}
+@item -V @tab @ref{--label}.
-@item -h
+@item -W @tab @ref{--verify}.
-@option{--dereference}
+@item -X @tab @ref{--exclude-from}.
-@item -i
+@item -Z @tab @ref{--compress}.
-@option{--ignore-zeros}
+@item -b @tab @ref{--blocking-factor}.
-@item -j
+@item -c @tab @ref{--create}.
-@option{--bzip2}
+@item -d @tab @ref{--compare}.
-@item -k
+@item -f @tab @ref{--file}.
-@option{--keep-old-files}
+@item -g @tab @ref{--listed-incremental}.
-@item -l
+@item -h @tab @ref{--dereference}.
-@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.
+@item -i @tab @ref{--ignore-zeros}.
-@xref{Changes}, for more information.
+@item -j @tab @ref{--bzip2}.
-@item -m
+@item -k @tab @ref{--keep-old-files}.
-@option{--touch}
+@item -l @tab @ref{--check-links}.
-@item -o
+@item -m @tab @ref{--touch}.
-When creating --- @option{--no-same-owner}, when extracting ---
-@option{--portability}.
+@item -o @tab When creating, @ref{--no-same-owner}, when extracting ---
+@ref{--portability}.
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
-
-@option{--preserve-permissions}
-
-@item -r
-
-@option{--append}
-
-@item -s
-
-@option{--same-order}
-
-@item -t
-
-@option{--list}
-
-@item -u
+@item -p @tab @ref{--preserve-permissions}.
-@option{--update}
+@item -r @tab @ref{--append}.
-@item -v
+@item -s @tab @ref{--same-order}.
-@option{--verbose}
+@item -t @tab @ref{--list}.
-@item -w
+@item -u @tab @ref{--update}.
-@option{--interactive}
+@item -v @tab @ref{--verbose}.
-@item -x
+@item -w @tab @ref{--interactive}.
-@option{--extract}
+@item -x @tab @ref{--extract}.
-@item -z
-
-@option{--gzip}
+@item -z @tab @ref{--gzip}.
-@end table
+@end multitable
@node help
@section @GNUTAR{} documentation
successfully. For example, @w{@samp{tar --version}} might print:
@smallexample
-tar (GNU tar) 1.15.2
+tar (GNU tar) @value{VERSION}
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software. You may redistribute copies of it under the terms of
the GNU General Public License <http://www.gnu.org/licenses/gpl.html>.
@cindex Obtaining help
@cindex Listing all @command{tar} options
-@opindex help, introduction
+@xopindex{help, introduction}
Another thing you might want to do is checking the spelling or meaning
of some particular @command{tar} option, without resorting to this
manual, for once you have carefully read it. @GNUTAR{}
back to the full documentation for precise points. If you are reading
this paragraph, you already have the @command{tar} manual in some
form. This manual is available in a variety of forms from
-@url{http://www.gnu.org/software/tar/manual}. It may printed out of the @GNUTAR{}
+@url{http://www.gnu.org/software/tar/manual}. It may be printed out of the @GNUTAR{}
distribution, provided you have @TeX{} already installed somewhere,
and a laser printer around. Just configure the distribution, execute
the command @w{@samp{make dvi}}, then print @file{doc/tar.dvi} the
@smallexample
@group
@kbd{tar --show-defaults}
---format=gnu -f- -b20 --rmt-command=/etc/rmt --rsh-command=/usr/bin/rsh
+--format=gnu -f- -b20 --quoting-style=escape
+--rmt-command=/etc/rmt --rsh-command=/usr/bin/rsh
@end group
@end smallexample
+@noindent
+Notice, that this option outputs only one line. The example output above
+has been split to fit page boundaries.
+
@noindent
The above output shows that this version of @GNUTAR{} defaults to
using @samp{gnu} archive format (@pxref{Formats}), it uses standard
With @option{--create} or @option{--extract}, @option{--verbose} used
once just prints the names of the files or members as they are processed.
Using it twice causes @command{tar} to print a longer listing
-(reminiscent of @samp{ls -l}) for each member. Since @option{--list}
-already prints the names of the members, @option{--verbose} used once
-with @option{--list} causes @command{tar} to print an @samp{ls -l}
-type listing of the files in the archive. The following examples both
-extract members with long list output:
+(@xref{verbose member listing}, for the description) for each member.
+Since @option{--list} already prints the names of the members,
+@option{--verbose} used once with @option{--list} causes @command{tar}
+to print an @samp{ls -l} type listing of the files in the archive.
+The following examples both extract members with long list output:
@smallexample
$ @kbd{tar --extract --file=archive.tar --verbose --verbose}
verbose output to @var{file} rather than to standard output or standard
error.
+@anchor{totals}
@cindex Obtaining total status information
@opindex totals
-The @option{--totals} option---which is only meaningful when used with
-@option{--create} (@option{-c})---causes @command{tar} to print the total
-amount written to the archive, after it has been fully created.
+The @option{--totals} option causes @command{tar} to print on the
+standard error the total amount of bytes transferred when processing
+an archive. When creating or appending to an archive, this option
+prints the number of bytes written to the archive and the average
+speed at which they have been written, e.g.:
+
+@smallexample
+@group
+$ @kbd{tar -c -f archive.tar --totals /home}
+Total bytes written: 7924664320 (7.4GiB, 85MiB/s)
+@end group
+@end smallexample
+
+When reading an archive, this option displays the number of bytes
+read:
+
+@smallexample
+@group
+$ @kbd{tar -x -f archive.tar --totals}
+Total bytes read: 7924664320 (7.4GiB, 95MiB/s)
+@end group
+@end smallexample
+
+Finally, when deleting from an archive, the @option{--totals} option
+displays both numbers plus number of bytes removed from the archive:
+
+@smallexample
+@group
+$ @kbd{tar --delete -f foo.tar --totals --wildcards '*~'}
+Total bytes read: 9543680 (9.2MiB, 201MiB/s)
+Total bytes written: 3829760 (3.7MiB, 81MiB/s)
+Total bytes deleted: 1474048
+@end group
+@end smallexample
+
+You can also obtain this information on request. When
+@option{--totals} is used with an argument, this argument is
+interpreted as a symbolic name of a signal, upon delivery of which the
+statistics is to be printed:
+@table @option
+@item --totals=@var{signo}
+Print statistics upon delivery of signal @var{signo}. Valid arguments
+are: @code{SIGHUP}, @code{SIGQUIT}, @code{SIGINT}, @code{SIGUSR1} and
+@code{SIGUSR2}. Shortened names without @samp{SIG} prefix are also
+accepted.
+@end table
+
+Both forms of @option{--totals} option can be used simultaneously.
+Thus, @kbd{tar -x --totals --totals=USR1} instructs @command{tar} to
+extract all members from its default archive and print statistics
+after finishing the extraction, as well as when receiving signal
+@code{SIGUSR1}.
+
+@anchor{Progress information}
@cindex Progress information
@opindex checkpoint
The @option{--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. It is designed for
those who don't need the more detailed (and voluminous) output of
@option{--block-number} (@option{-R}), but do want visual confirmation
-that @command{tar} is actually making forward progress.
+that @command{tar} is actually making forward progress. By default it
+prints a message each 10 records read or written. This can be changed
+by giving it a numeric argument after an equal sign:
+
+@smallexample
+$ @kbd{tar -c --checkpoint=1000} /var
+tar: Write checkpoint 1000
+tar: Write checkpoint 2000
+tar: Write checkpoint 3000
+@end smallexample
+
+This example shows the default checkpoint message used by
+@command{tar}. If you place a dot immediately after the equal
+sign, it will print a @samp{.} at each checkpoint. For example:
-@FIXME{There is some confusion here. It seems that -R once wrote a
-message at @samp{every} record read or written.}
+@smallexample
+$ @kbd{tar -c --checkpoint=.1000} /var
+...
+@end smallexample
@opindex show-omitted-dirs
@anchor{show-omitted-dirs}
to be printed for each directory in the archive which is skipped.
This happens regardless of the reason for skipping: the directory might
not have been named on the command line (implicitly or explicitly),
-it might be excluded by the use of the @option{--exclude=@var{pattern}} option, or
-some other reason.
+it might be excluded by the use of the
+@option{--exclude=@var{pattern}} option, or some other reason.
@opindex block-number
@cindex Block number where error occurred
for these operations.
@table @option
-@opindex create, complementary notes
+@xopindex{create, complementary notes}
@item --create
@itemx -c
@kbd{tar cfT empty-archive.tar /dev/null}
@end smallexample
-@opindex extract, complementary notes
+@xopindex{extract, complementary notes}
@item --extract
@itemx --get
@itemx -x
ready. In the meantime, programs not being localizable for dates
should prefer international dates, that's really the way to go.
-Look up @url{http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html} if you
+Look up @url{http://www.ft.uni-erlangen.de/@/~mskuhn/@/iso-time.html} if you
are curious, it contains a detailed explanation of the ISO 8601 standard.
@end table
* concatenate::
* delete::
* compare::
-* quoting styles::
@end menu
@node Operations
@end smallexample
@node multiple
-@subsubsection Multiple Files with the Same Name
+@subsubsection Multiple Members with the Same Name
You can use @option{--append} (@option{-r}) to add copies of files
which have been updated since the archive was created. (However, we
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 @option{--backup} option. @FIXME-ref{Multiple Members with the
-Same Name}
+the @option{--backup} option. @xref{multiple}, for a detailed discussion.
@menu
* how to update::
@option{--file} option and name the rest of archives to be
concatenated on the command line. The members, and their member
names, will be copied verbatim from those archives to the first one.
-@FIXME-ref{This can cause multiple members to have the same name, for
-information on how this affects reading the archive, Multiple
-Members with the Same Name.}
+@footnote{This can cause multiple members to have the same name, for
+information on how this affects reading the archive, @ref{multiple}.}
The new, concatenated archive will be called by the same name as the
one given with the @option{--file} option. As usual, if you omit
@option{--file}, @command{tar} will use the value of the environment
current state of files on disk, more than validating the integrity of
the archive media. For this later goal, @xref{verify}.
-@node quoting styles
-@subsection Quoting Member Names
-
-When displaying member names, @command{tar} takes care to avoid
-ambiguities caused by certain characters. This is called @dfn{name
-quoting}. The characters in question are:
+@node create options
+@section Options Used by @option{--create}
-@itemize @bullet
-@item Non-printable control characters:
-
-@multitable @columnfractions 0.20 0.10 0.60
-@headitem Character @tab ASCII @tab Character name
-@item \a @tab 7 @tab Audible bell
-@item \b @tab 8 @tab Backspace
-@item \f @tab 12 @tab Form feed
-@item \n @tab 10 @tab New line
-@item \r @tab 13 @tab Carriage return
-@item \t @tab 9 @tab Horizontal tabulation
-@item \v @tab 11 @tab Vertical tabulation
-@end multitable
-
-@item Space (ASCII 32)
-
-@item Single and double quotes (@samp{'} and @samp{"})
-
-@item Backslash (@samp{\})
-@end itemize
-
-The exact way @command{tar} uses to quote these characters depends on
-the @dfn{quoting style}. The default quoting style, called
-@dfn{escape} (see below), uses backslash notation to represent control
-characters, space and backslash. Using this quoting style, control
-characters are represented as listed in column @samp{Character} in the
-above table, a space is printed as @samp{\ } and a backslash as @samp{\\}.
-
-@GNUTAR{} offers seven distinct quoting styles, which can be selected
-using @option{--quoting-style} option:
-
-@table @option
-@item --quoting-style=@var{style}
-@opindex quoting-style
-
-Sets quoting style. Valid values for @var{style} argument are:
-literal, shell, shell-always, c, escape, locale, clocale.
-@end table
-
-These styles are described in detail below. To illustrate their
-effect, we will use an imaginary tar archive @file{arch.tar}
-containing the following members:
-
-@smallexample
-@group
-# 1. Contains horizontal tabulation character.
-a tab
-# 2. Contains newline character
-a
-newline
-# 3. Contains a space
-a space
-# 4. Contains double quotes
-a"double"quote
-# 5. Contains single quotes
-a'single'quote
-# 6. Contains a backslash character:
-a\backslash
-@end group
-@end smallexample
-
-Here is how usual @command{ls} command would have listed them, if they
-had existed in the current working directory:
-
-@smallexample
-@group
-$ @kbd{ls}
-a\ttab
-a\nnewline
-a\ space
-a"double"quote
-a'single'quote
-a\\backslash
-@end group
-@end smallexample
-
-Quoting styles:
-
-@table @samp
-@item literal
-No quoting, display each character as is:
-
-@smallexample
-@group
-$ @kbd{tar tf arch.tar --quoting-style=literal}
-./
-./a space
-./a'single'quote
-./a"double"quote
-./a\backslash
-./a tab
-./a
-newline
-@end group
-@end smallexample
-
-@item shell
-Display characters the same way Bourne shell does:
-control characters, except @samp{\t} and @samp{\n}, are printed using
-backslash escapes, @samp{\t} and @samp{\n} are printed as is, and a
-single quote is printed as @samp{\'}. If a name contains any quoted
-characters, it is enclosed in single quotes. In particular, if a name
-contains single quotes, it is printed as several single-quoted strings:
-
-@smallexample
-@group
-$ @kbd{tar tf arch.tar --quoting-style=shell}
-./
-'./a space'
-'./a'\''single'\''quote'
-'./a"double"quote'
-'./a\backslash'
-'./a tab'
-'./a
-newline'
-@end group
-@end smallexample
-
-@item shell-always
-Same as @samp{shell}, but the names are always enclosed in single
-quotes:
-
-@smallexample
-@group
-$ @kbd{tar tf arch.tar --quoting-style=shell-always}
-'./'
-'./a space'
-'./a'\''single'\''quote'
-'./a"double"quote'
-'./a\backslash'
-'./a tab'
-'./a
-newline'
-@end group
-@end smallexample
-
-@item c
-Use the notation of the C programming language. All names are
-enclosed in double quotes. Control characters are quoted using
-backslash notations, double quotes are represented as @samp{\"},
-backslash characters are represented as @samp{\\}. Single quotes and
-spaces are not quoted:
-
-@smallexample
-@group
-$ @kbd{tar tf arch.tar --quoting-style=c}
-"./"
-"./a space"
-"./a'single'quote"
-"./a\"double\"quote"
-"./a\\backslash"
-"./a\ttab"
-"./a\nnewline"
-@end group
-@end smallexample
-
-@item escape
-Control characters are printed using backslash notation, a space is
-printed as @samp{\ } and a backslash as @samp{\\}. This is the
-default quoting style, unless it was changed when configured the
-package.
-
-@smallexample
-@group
-$ @kbd{tar tf arch.tar --quoting-style=escape}
-./
-./a space
-./a'single'quote
-./a"double"quote
-./a\\backslash
-./a\ttab
-./a\nnewline
-@end group
-@end smallexample
-
-@item locale
-Control characters, single quote and backslash are printed using
-backslash notation. All names are quoted using left and right
-quotation marks, appropriate to the current locale. If it does not
-define quotation marks, use @samp{`} as left and @samp{'} as right
-quotation marks. Any occurrences of the right quotation mark in a
-name are escaped with @samp{\}, for example:
-
-For example:
-
-@smallexample
-@group
-$ @kbd{tar tf arch.tar --quoting-style=locale}
-`./'
-`./a space'
-`./a\'single\'quote'
-`./a"double"quote'
-`./a\\backslash'
-`./a\ttab'
-`./a\nnewline'
-@end group
-@end smallexample
-
-@item clocale
-Same as @samp{locale}, but @samp{"} is used for both left and right
-quotation marks, if not provided by the currently selected locale:
-
-@smallexample
-@group
-$ @kbd{tar tf arch.tar --quoting-style=clocale}
-"./"
-"./a space"
-"./a'single'quote"
-"./a\"double\"quote"
-"./a\\backslash"
-"./a\ttab"
-"./a\nnewline"
-@end group
-@end smallexample
-@end table
-
-You can specify which characters should be quoted in addition to those
-implied by the current quoting style:
-
-@table @option
-@item --quote-chars=@var{string}
-Always quote characters from @var{string}, even if the selected
-quoting style would not quote them.
-@end table
-
-For example, using @samp{escape} quoting (compare with the usual
-escape listing above):
-
-@smallexample
-@group
-$ @kbd{tar tf arch.tar --quoting-style=escape --quote-chars=' "'}
-./
-./a\ space
-./a'single'quote
-./a\"double\"quote
-./a\\backslash
-./a\ttab
-./a\nnewline
-@end group
-@end smallexample
-
-To disable quoting of such additional characters, use the following
-option:
-
-@table @option
-@item --no-quote-chars=@var{string}
-Remove characters listed in @var{string} from the list of quoted
-characters set by the previous @option{--quote-chars} option.
-@end table
-
-This option is particularly useful if you have added
-@option{--quote-chars} to your @env{TAR_OPTIONS} (@pxref{TAR_OPTIONS})
-and wish to disable it for the current invocation.
-
-Note, that @option{--no-quote-chars} does @emph{not} disable those
-characters that are quoted by default in the selected quoting style.
-
-@node create options
-@section Options Used by @option{--create}
-
-@opindex create, additional options
-The previous chapter described the basics of how to use
-@option{--create} (@option{-c}) to create an archive from a set of files.
-@xref{create}. This section described advanced options to be used with
-@option{--create}.
+@xopindex{create, additional options}
+The previous chapter described the basics of how to use
+@option{--create} (@option{-c}) to create an archive from a set of files.
+@xref{create}. This section described advanced options to be used with
+@option{--create}.
@menu
* Ignore Failed Read::
@section Options Used by @option{--extract}
@UNREVISED
-@opindex extract, additional options
+@xopindex{extract, additional options}
The previous chapter showed how to use @option{--extract} to extract
an archive into the file system. Various options cause @command{tar} to
extract more information than just file contents, such as the owner,
@node Dealing with Old Files
@unnumberedsubsubsec Options Controlling the Overwriting of Existing Files
-@opindex overwrite-dir, introduced
+@xopindex{overwrite-dir, introduced}
When extracting files, if @command{tar} discovers that the extracted
file already exists, it normally replaces the file by removing it before
extracting it, to prevent confusion in the presence of hard or symbolic
such a directory, use the @option{--no-overwrite-dir} option.
@cindex Overwriting old files, prevention
-@opindex keep-old-files, introduced
+@xopindex{keep-old-files, introduced}
To be even more cautious and prevent existing files from being replaced, use
the @option{--keep-old-files} (@option{-k}) option. It causes @command{tar} to refuse
to replace or update a file that already exists, i.e., a file with the
same name as an archive member prevents extraction of that archive
member. Instead, it reports an error.
-@opindex overwrite, introduced
+@xopindex{overwrite, introduced}
To be more aggressive about altering existing files, use the
@option{--overwrite} option. It causes @command{tar} to overwrite
existing files and to follow existing symbolic links when extracting.
to allow this behavior. In any case, single files are silently
removed.
-@opindex unlink-first, introduced
+@xopindex{unlink-first, introduced}
Finally, the @option{--unlink-first} (@option{-U}) option can improve performance in
some cases by causing @command{tar} to remove files unconditionally
before extracting them.
@option{-x}) operation.
@table @option
-@opindex preserve-permission
-@opindex same-permission
-@item --preserve-permission
-@itemx --same-permission
+@opindex preserve-permissions
+@opindex same-permissions
+@item --preserve-permissions
+@itemx --same-permissions
@c @itemx --ignore-umask
@itemx -p
Set modes of extracted archive members to those recorded in the
@end table
-Some people express the desire to @emph{always} use the @option{--backup}
-option, by defining some kind of alias or script. This is not as easy
-as one may think, due to the fact that old style options should appear first
-and consume arguments a bit unpredictably for an alias or script. But,
-if you are ready to give up using old style options, you may resort to
-using something like (a Bourne shell function here):
-
-@smallexample
-tar () @{ /usr/local/bin/tar --backup $*; @}
-@end smallexample
-
@node Applications
@section Notable @command{tar} Usages
@UNREVISED
Note that incremental archives use @command{tar} extensions and may
not be readable by non-@acronym{GNU} versions of the @command{tar} program.
-@opindex listed-incremental, using with @option{--extract}
-@opindex extract, using with @option{--listed-incremental}
+@xopindex{listed-incremental, using with @option{--extract}}
+@xopindex{extract, using with @option{--listed-incremental}}
To extract from the incremental dumps, use
@option{--listed-incremental} together with @option{--extract}
option (@pxref{extracting files}). In this case, @command{tar} does
verbose listing output (@option{--list --verbose}) when using in
scripts.
-@opindex incremental, using with @option{--list}
-@opindex listed-incremental, using with @option{--list}
-@opindex list, using with @option{--incremental}
-@opindex list, using with @option{--listed-incremental}
+@xopindex{incremental, using with @option{--list}}
+@xopindex{listed-incremental, using with @option{--list}}
+@xopindex{list, using with @option{--incremental}}
+@xopindex{list, using with @option{--listed-incremental}}
Versions of @GNUTAR{} up to 1.15.1 used to dump verbatim binary
contents of the DUMPDIR header (with terminating nulls) when
@option{--incremental} or @option{--listed-incremental} option was
where @var{x} is a letter describing the status of the file: @samp{Y}
if the file is present in the archive, @samp{N} if the file is not
included in the archive, or a @samp{D} if the file is a directory (and
-is included in the archive).@FIXME-xref{dumpdir format}. Each such
+is included in the archive). @xref{Dumpdir}, for the detailed
+description of dumpdirs and status codes. Each such
line is terminated by a newline character. The last line is followed
by an additional newline to indicate the end of the data.
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 (i.e. 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.
This variable affects only @code{backup}.
@end defvr
-@defvr {Backup variable} SLEEP_TIME
+@defvr {Backup variable} SLEEP_TIME
+
+Time to sleep between dumps of any two successive file systems
+
+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.
+If this variable isn't set, @GNUTAR{} will display its built-in
+prompt, and will expect confirmation from the console. For the
+description of the default prompt, see @ref{change volume prompt}.
+
+@end defvr
+
+@defvr {Backup variable} SLEEP_MESSAGE
+
+Message to display on the terminal while waiting for dump time. Usually
+this will just be some literal text.
+@end defvr
+
+@defvr {Backup variable} TAR
+
+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
+
+@node Magnetic Tape Control
+@subsection Magnetic Tape Control
+
+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:
+
+@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:
+
+@smallexample
+MT_BEGIN=mt_begin
+
+mt_begin() @{
+ mt -f "$1" retension
+@}
+@end smallexample
+@end defvr
+
+@defvr {Backup variable} MT_REWIND
+The name of @dfn{rewind} function. The default definition is as
+follows:
+
+@smallexample
+MT_REWIND=mt_rewind
+
+mt_rewind() @{
+ mt -f "$1" rewind
+@}
+@end smallexample
+
+@end defvr
+
+@defvr {Backup variable} MT_OFFLINE
+The name of the function switching the tape off line. By default
+it is defined as follows:
+
+@smallexample
+MT_OFFLINE=mt_offline
+
+mt_offline() @{
+ mt -f "$1" offl
+@}
+@end smallexample
+@end defvr
+
+@defvr {Backup variable} MT_STATUS
+The name of the function used to obtain the status of the archive device,
+including error count. Default definition:
+
+@smallexample
+MT_STATUS=mt_status
+
+mt_status() @{
+ mt -f "$1" status
+@}
+@end smallexample
+@end defvr
+
+@node User Hooks
+@subsection User Hooks
+
+@dfn{User hooks} are shell functions executed before and after
+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
+taking four arguments:
+
+@deffn {User Hook Function} hook @var{level} @var{host} @var{fs} @var{fsname}
+Its arguments are:
+
+@table @var
+@item level
+Current backup or restore level.
+
+@item host
+Name or IP address of the host machine being dumped or restored.
+
+@item fs
+Full path name to the file system being dumped or restored.
+
+@item fsname
+File system 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 file system.
+@end defvr
+
+@defvr {Backup variable} DUMP_END
+Executed after dumping the file system.
+@end defvr
+
+@defvr {Backup variable} RESTORE_BEGIN
+Executed before restoring the file system.
+@end defvr
+
+@defvr {Backup variable} RESTORE_END
+Executed after restoring the file system.
+@end defvr
+
+@node backup-specs example
+@subsection An Example Text of @file{Backup-specs}
+
+The following is an example of @file{backup-specs}:
+
+@smallexample
+# site-specific parameters for file system backup.
+
+ADMINISTRATOR=friedman
+BACKUP_HOUR=1
+TAPE_FILE=/dev/nrsmt0
+
+# Use @code{ssh} instead of the less secure @code{rsh}
+RSH=/usr/bin/ssh
+RSH_COMMAND=/usr/bin/ssh
+
+# Override MT_STATUS function:
+my_status() @{
+ mts -t $TAPE_FILE
+@}
+MT_STATUS=my_status
+
+# Disable MT_OFFLINE function
+MT_OFFLINE=:
+
+BLOCKING=124
+BACKUP_DIRS="
+ albert:/fs/fsf
+ apple-gunkies:/gd
+ albert:/fs/gd2
+ albert:/fs/gp
+ geech:/usr/jla
+ churchy:/usr/roland
+ albert:/
+ albert:/usr
+ apple-gunkies:/
+ apple-gunkies:/usr
+ gnu:/hack
+ gnu:/u
+ apple-gunkies:/com/mailer/gnu
+ apple-gunkies:/com/archive/gnu"
+
+BACKUP_FILES="/com/mailer/aliases /com/mailer/league*[a-z]"
+
+@end smallexample
+
+@node Scripted Backups
+@section Using the Backup Scripts
+
+The syntax for running a backup script is:
+
+@smallexample
+backup --level=@var{level} --time=@var{time}
+@end smallexample
+
+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-}
+followed by a single decimal digit, that digit is taken as
+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:
+
+@table @asis
+@item @var{hh}:@var{mm}
+
+The dump must be run at @var{hh} hours @var{mm} minutes.
+
+@item @var{hh}
+
+The dump must be run at @var{hh} hours
+
+@item now
+
+The dump must be run immediately.
+@end table
+
+You should start a script with a tape or disk mounted. Once you
+start a script, it prompts you for new tapes or disks as it
+needs them. Media volumes don't have to correspond to archive
+files --- a multi-volume archive can be started in the middle of a
+tape that already contains the end of another multi-volume archive.
+The @code{restore} script prompts for media by its archive volume,
+so to avoid an error message you should keep track of which tape
+(or disk) contains which volume of the archive (@pxref{Scripted
+Restoration}).
+
+The backup scripts write two files on the file system. The first is a
+record file in @file{/etc/tar-backup/}, which is used by the scripts
+to store and retrieve information about which files were dumped. This
+file is not meant to be read by humans, and should not be deleted by
+them. @xref{Snapshot Files}, for a more detailed explanation of this
+file.
+
+The second file is a log file containing the names of the file systems
+and files dumped, what time the backup was made, and any error
+messages that were generated, as well as how much space was left in
+the media volume after the last volume of the archive was written.
+You should check this log file after every backup. The file name is
+@file{log-@var{mm-dd-yyyy}-level-@var{n}}, where @var{mm-dd-yyyy}
+represents current date, and @var{n} represents current dump level number.
+
+The script also prints the name of each system being dumped to the
+standard output.
-Time to sleep between dumps of any two successive file systems
+Following is the full list of options accepted by @code{backup}
+script:
-This variable affects only @code{backup}.
-@end defvr
+@table @option
+@item -l @var{level}
+@itemx --level=@var{level}
+Do backup level @var{level} (default 0).
-@defvr {Backup variable} DUMP_REMIND_SCRIPT
+@item -f
+@itemx --force
+Force backup even if today's log file already exists.
-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.
-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.
-@end defvr
+@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}
+is 100, which means the highest debugging level.
-@defvr {Backup variable} SLEEP_MESSAGE
+@item -t @var{start-time}
+@itemx --time=@var{start-time}
+Wait till @var{time}, then do backup.
-Message to display on the terminal while waiting for dump time. Usually
-this will just be some literal text.
-@end defvr
+@item -h
+@itemx --help
+Display short help message and exit.
-@defvr {Backup variable} TAR
+@item -V
+@itemx --version
+Display information about the program's name, version, origin and legal
+status, all on standard output, and then exit successfully.
+@end table
-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
-@node Magnetic Tape Control
-@subsection Magnetic Tape Control
+@node Scripted Restoration
+@section Using the Restore Script
-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:
+To restore files that were archived using a scripted backup, use the
+@code{restore} script. Its usage is quite straightforward. In the
+simplest form, invoke @code{restore --all}, it will
+then restore all the file systems and files specified in
+@file{backup-specs} (@pxref{General-Purpose Variables,BACKUP_DIRS}).
-@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:
+You may select the file systems (and/or files) to restore by
+giving @code{restore} list of @dfn{patterns} in its command
+line. For example, running
@smallexample
-MT_BEGIN=mt_begin
-
-mt_begin() @{
- mt -f "$1" retension
-@}
+restore 'albert:*'
@end smallexample
-@end defvr
-@defvr {Backup variable} MT_REWIND
-The name of @dfn{rewind} function. The default definition is as
-follows:
+@noindent
+will restore all file systems on the machine @samp{albert}. A more
+complicated example:
@smallexample
-MT_REWIND=mt_rewind
-
-mt_rewind() @{
- mt -f "$1" rewind
-@}
+restore 'albert:*' '*:/var'
@end smallexample
-@end defvr
+@noindent
+This command will restore all file systems on the machine @samp{albert}
+as well as @file{/var} file system on all machines.
-@defvr {Backup variable} MT_OFFLINE
-The name of the function switching the tape off line. By default
-it is defined as follows:
+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,
+use @option{--level} option, as shown in the example below:
@smallexample
-MT_OFFLINE=mt_offline
-
-mt_offline() @{
- mt -f "$1" offl
-@}
+restore --level=1
@end smallexample
-@end defvr
-@defvr {Backup variable} MT_STATUS
-The name of the function used to obtain the status of the archive device,
-including error count. Default definition:
+The full list of options accepted by @code{restore} follows:
-@smallexample
-MT_STATUS=mt_status
+@table @option
+@item -a
+@itemx --all
+Restore all file systems and files specified in @file{backup-specs}
-mt_status() @{
- mt -f "$1" status
-@}
-@end smallexample
-@end defvr
+@item -l @var{level}
+@itemx --level=@var{level}
+Start restoring from the given backup level, instead of the default 0.
-@node User Hooks
-@subsection User Hooks
+@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}
+is 100, which means the highest debugging level.
-@dfn{User hooks} are shell functions executed before and after
-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
-taking four arguments:
+@item -h
+@itemx --help
+Display short help message and exit.
-@deffn {User Hook Function} hook @var{level} @var{host} @var{fs} @var{fsname}
-Its arguments are:
+@item -V
+@itemx --version
+Display information about the program's name, version, origin and legal
+status, all on standard output, and then exit successfully.
+@end table
-@table @var
-@item level
-Current backup or restore level.
+You should start the restore script with the media containing the
+first volume of the archive mounted. The script will prompt for other
+volumes as they are needed. If the archive is on tape, you don't need
+to rewind the tape to to its beginning---if the tape head is
+positioned past the beginning of the archive, the script will rewind
+the tape as needed. @xref{Tape Positioning}, for a discussion of tape
+positioning.
-@item host
-Name or IP address of the host machine being dumped or restored.
+@quotation
+@strong{Warning:} The script will delete files from the active file
+system if they were not in the file system when the archive was made.
+@end quotation
-@item fs
-Full path name to the file system being dumped or restored.
+@xref{Incremental Dumps}, for an explanation of how the script makes
+that determination.
-@item fsname
-File system name with directory separators replaced with colons. This
-is useful, e.g., for creating unique files.
+@node Choosing
+@chapter Choosing Files and Names for @command{tar}
+@UNREVISED
+
+Certain options to @command{tar} enable you to specify a name for your
+archive. Other options let you decide which files to include or exclude
+from the archive, based on when or whether files were modified, whether
+the file names do or don't match specified patterns, or whether files
+are in specified directories.
+
+This chapter discusses these options in detail.
+
+@menu
+* file:: Choosing the Archive's Name
+* Selecting Archive Members::
+* files:: Reading Names from a File
+* exclude:: Excluding Some Files
+* wildcards:: Wildcards Patterns and Matching
+* quoting styles:: Ways of Quoting Special Characters in Names
+* transform:: Modifying File and Member Names
+* after:: Operating Only on New Files
+* recurse:: Descending into Directories
+* one:: Crossing File System Boundaries
+@end menu
+
+@node file
+@section Choosing and Naming Archive Files
+@UNREVISED
+
+@cindex Naming an archive
+@cindex Archive Name
+@cindex Choosing an archive file
+@cindex Where is the archive?
+By default, @command{tar} uses an archive file name that was compiled when
+it was built on the system; usually this name refers to some physical
+tape drive on the machine. However, the person who installed @command{tar}
+on the system may not have set the default to a meaningful value as far as
+most users are concerned. As a result, you will usually want to tell
+@command{tar} where to find (or create) the archive. The
+@option{--file=@var{archive-name}} (@option{-f @var{archive-name}})
+option allows you to either specify or name a file to use as the archive
+instead of the default archive file location.
+
+@table @option
+@xopindex{file, short description}
+@item --file=@var{archive-name}
+@itemx -f @var{archive-name}
+Name the archive to create or operate on. Use in conjunction with
+any operation.
@end table
-@end deffn
-Following variables keep the names of user hook functions
+For example, in this @command{tar} command,
-@defvr {Backup variable} DUMP_BEGIN
-Dump begin function. It is executed before dumping the file system.
-@end defvr
+@smallexample
+$ @kbd{tar -cvf collection.tar blues folk jazz}
+@end smallexample
-@defvr {Backup variable} DUMP_END
-Executed after dumping the file system.
-@end defvr
+@noindent
+@file{collection.tar} is the name of the archive. It must directly
+follow the @option{-f} option, since whatever directly follows @option{-f}
+@emph{will} end up naming the archive. If you neglect to specify an
+archive name, you may end up overwriting a file in the working directory
+with the archive you create since @command{tar} will use this file's name
+for the archive name.
-@defvr {Backup variable} RESTORE_BEGIN
-Executed before restoring the file system.
-@end defvr
+An archive can be saved as a file in the file system, sent through a
+pipe or over a network, or written to an I/O device such as a tape,
+floppy disk, or CD write drive.
+
+@cindex Writing new archives
+@cindex Archive creation
+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 (i.e. @file{/dev/tu00}).
+
+@cindex Standard input and output
+@cindex tar to standard input and output
+If you use @file{-} as an @var{archive-name}, @command{tar} reads the
+archive from standard input (when listing or extracting files), or
+writes it to standard output (when creating an archive). If you use
+@file{-} as an @var{archive-name} when modifying an archive,
+@command{tar} reads the original archive from its standard input and
+writes the entire new archive to its standard output.
+
+The following example is a convenient way of copying directory
+hierarchy from @file{sourcedir} to @file{targetdir}.
+
+@smallexample
+$ @kbd{(cd sourcedir; tar -cf - .) | (cd targetdir; tar -xpf -)}
+@end smallexample
+
+The @option{-C} option allows to avoid using subshells:
-@defvr {Backup variable} RESTORE_END
-Executed after restoring the file system.
-@end defvr
+@smallexample
+$ @kbd{tar -C sourcedir -cf - . | tar -C targetdir -xpf -}
+@end smallexample
-@node backup-specs example
-@subsection An Example Text of @file{Backup-specs}
+In both examples above, the leftmost @command{tar} invocation archives
+the contents of @file{sourcedir} to the standard output, while the
+rightmost one reads this archive from its standard input and
+extracts it. The @option{-p} option tells it to restore permissions
+of the extracted files.
-The following is an example of @file{backup-specs}:
+@cindex Remote devices
+@cindex tar to a remote device
+@anchor{remote-dev}
+To specify an archive file on a device attached to a remote machine,
+use the following:
@smallexample
-# site-specific parameters for file system backup.
-
-ADMINISTRATOR=friedman
-BACKUP_HOUR=1
-TAPE_FILE=/dev/nrsmt0
+@kbd{--file=@var{hostname}:/@var{dev}/@var{file-name}}
+@end smallexample
-# Use @code{ssh} instead of the less secure @code{rsh}
-RSH=/usr/bin/ssh
-RSH_COMMAND=/usr/bin/ssh
+@noindent
+@command{tar} will complete the remote connection, if possible, and
+prompt you for a username and password. If you use
+@option{--file=@@@var{hostname}:/@var{dev}/@var{file-name}}, @command{tar}
+will complete the remote connection, if possible, using your username
+as the username on the remote machine.
-# Override MT_STATUS function:
-my_status() @{
- mts -t $TAPE_FILE
-@}
-MT_STATUS=my_status
+@cindex Local and remote archives
+@anchor{local and remote archives}
+If the archive file name includes a colon (@samp{:}), then it is assumed
+to be a file on another machine. If the archive file is
+@samp{@var{user}@@@var{host}:@var{file}}, then @var{file} is used on the
+host @var{host}. The remote host is accessed using the @command{rsh}
+program, with a username of @var{user}. If the username is omitted
+(along with the @samp{@@} sign), then your user name will be used.
+(This is the normal @command{rsh} behavior.) It is necessary for the
+remote machine, in addition to permitting your @command{rsh} access, to
+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
+colon, then the remote tape drive behavior
+can be inhibited by using the @option{--force-local} option.
-# Disable MT_OFFLINE function
-MT_OFFLINE=:
+When the archive is being created to @file{/dev/null}, @GNUTAR{}
+tries to minimize input and output operations. The Amanda backup
+system, when used with @GNUTAR{}, has an initial sizing pass which
+uses this feature.
-BLOCKING=124
-BACKUP_DIRS="
- albert:/fs/fsf
- apple-gunkies:/gd
- albert:/fs/gd2
- albert:/fs/gp
- geech:/usr/jla
- churchy:/usr/roland
- albert:/
- albert:/usr
- apple-gunkies:/
- apple-gunkies:/usr
- gnu:/hack
- gnu:/u
- apple-gunkies:/com/mailer/gnu
- apple-gunkies:/com/archive/gnu"
+@node Selecting Archive Members
+@section Selecting Archive Members
+@cindex Specifying files to act on
+@cindex Specifying archive members
-BACKUP_FILES="/com/mailer/aliases /com/mailer/league*[a-z]"
+@dfn{File Name arguments} specify which files in the file system
+@command{tar} operates on, when creating or adding to an archive, or which
+archive members @command{tar} operates on, when reading or deleting from
+an archive. @xref{Operations}.
+To specify file names, you can include them as the last arguments on
+the command line, as follows:
+@smallexample
+@kbd{tar} @var{operation} [@var{option1} @var{option2} @dots{}] [@var{file name-1} @var{file name-2} @dots{}]
@end smallexample
-@node Scripted Backups
-@section Using the Backup Scripts
+If a file name begins with dash (@samp{-}), precede it with
+@option{--add-file} option to prevent it from being treated as an
+option.
-The syntax for running a backup script is:
+@anchor{input name quoting}
+By default @GNUTAR{} attempts to @dfn{unquote} each file or member
+name, replacing @dfn{escape sequences} according to the following
+table:
+
+@multitable @columnfractions 0.20 0.60
+@headitem Escape @tab Replaced with
+@item \a @tab Audible bell (ASCII 7)
+@item \b @tab Backspace (ASCII 8)
+@item \f @tab Form feed (ASCII 12)
+@item \n @tab New line (ASCII 10)
+@item \r @tab Carriage return (ASCII 13)
+@item \t @tab Horizontal tabulation (ASCII 9)
+@item \v @tab Vertical tabulation (ASCII 11)
+@item \? @tab ASCII 127
+@item \@var{n} @tab ASCII @var{n} (@var{n} should be an octal number
+ of up to 3 digits)
+@end multitable
-@smallexample
-backup --level=@var{level} --time=@var{time}
-@end smallexample
+A backslash followed by any other symbol is retained.
-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-}
-followed by a single decimal digit, that digit is taken as
-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.}
+This default behavior is controlled by the following command line
+option:
-The @option{--time} option determines when should the backup be
-run. @var{Time} may take three forms:
+@table @option
+@opindex unquote
+@item --unquote
+Enable unquoting input file or member names (default).
-@table @asis
-@item @var{hh}:@var{mm}
+@opindex no-unquote
+@item --no-unquote
+Disable unquoting input file or member names.
+@end table
-The dump must be run at @var{hh} hours @var{mm} minutes.
+If you specify a directory name as a file name argument, all the files
+in that directory are operated on by @command{tar}.
-@item @var{hh}
+If you do not specify files, @command{tar} behavior differs depending
+on the operation mode as described below:
-The dump must be run at @var{hh} hours
+When @command{tar} is invoked with @option{--create} (@option{-c}),
+@command{tar} will stop immediately, reporting the following:
-@item now
+@smallexample
+@group
+$ @kbd{tar cf a.tar}
+tar: Cowardly refusing to create an empty archive
+Try `tar --help' or `tar --usage' for more information.
+@end group
+@end smallexample
-The dump must be run immediately.
-@end table
+If you specify either @option{--list} (@option{-t}) or
+@option{--extract} (@option{--get}, @option{-x}), @command{tar}
+operates on all the archive members in the archive.
-You should start a script with a tape or disk mounted. Once you
-start a script, it prompts you for new tapes or disks as it
-needs them. Media volumes don't have to correspond to archive
-files --- a multi-volume archive can be started in the middle of a
-tape that already contains the end of another multi-volume archive.
-The @code{restore} script prompts for media by its archive volume,
-so to avoid an error message you should keep track of which tape
-(or disk) contains which volume of the archive (@pxref{Scripted
-Restoration}).
+If run with @option{--diff} option, tar will compare the archive with
+the contents of the current working directory.
-The backup scripts write two files on the file system. The first is a
-record file in @file{/etc/tar-backup/}, which is used by the scripts
-to store and retrieve information about which files were dumped. This
-file is not meant to be read by humans, and should not be deleted by
-them. @xref{Snapshot Files}, for a more detailed explanation of this
-file.
+If you specify any other operation, @command{tar} does nothing.
-The second file is a log file containing the names of the file systems
-and files dumped, what time the backup was made, and any error
-messages that were generated, as well as how much space was left in
-the media volume after the last volume of the archive was written.
-You should check this log file after every backup. The file name is
-@file{log-@var{mm-dd-yyyy}-level-@var{n}}, where @var{mm-dd-yyyy}
-represents current date, and @var{n} represents current dump level number.
+By default, @command{tar} takes file names from the command line. However,
+there are other ways to specify file or member names, or to modify the
+manner in which @command{tar} selects the files or members upon which to
+operate. In general, these methods work both for specifying the names
+of files and archive members.
-The script also prints the name of each system being dumped to the
-standard output.
+@node files
+@section Reading Names from a File
-Following is the full list of options accepted by @code{backup}
-script:
+@cindex Reading file names from a file
+@cindex Lists of file names
+@cindex File Name arguments, alternatives
+Instead of giving the names of files or archive members on the command
+line, you can put the names into a file, and then use the
+@option{--files-from=@var{file-of-names}} (@option{-T
+@var{file-of-names}}) 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
+the list of files to archive with the @command{find} utility.
@table @option
-@item -l @var{level}
-@itemx --level=@var{level}
-Do backup level @var{level} (default 0).
-
-@item -f
-@itemx --force
-Force backup even if today's log file already exists.
+@opindex files-from
+@item --files-from=@var{file-name}
+@itemx -T @var{file-name}
+Get names to extract or create from file @var{file-name}.
+@end table
-@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}
-is 100, which means the highest debugging level.
+If you give a single dash as a file name for @option{--files-from}, (i.e.,
+you specify either @code{--files-from=-} or @code{-T -}), then the file
+names are read from standard input.
-@item -t @var{start-time}
-@itemx --time=@var{start-time}
-Wait till @var{time}, then do backup.
+Unless you are running @command{tar} with @option{--create}, you can not use
+both @code{--files-from=-} and @code{--file=-} (@code{-f -}) in the same
+command.
-@item -h
-@itemx --help
-Display short help message and exit.
+Any number of @option{-T} options can be given in the command line.
-@item -V
-@itemx --version
-Display information about the program's name, version, origin and legal
-status, all on standard output, and then exit successfully.
-@end table
+The following example shows how to use @command{find} to generate a list of
+files smaller than 400K in length and put that list into a file
+called @file{small-files}. You can then use the @option{-T} option to
+@command{tar} to specify the files from that file, @file{small-files}, to
+create the archive @file{little.tgz}. (The @option{-z} option to
+@command{tar} compresses the archive with @command{gzip}; @pxref{gzip} for
+more information.)
+@smallexample
+$ @kbd{find . -size -400 -print > small-files}
+$ @kbd{tar -c -v -z -T small-files -f little.tgz}
+@end smallexample
-@node Scripted Restoration
-@section Using the Restore Script
+@noindent
+In the file list given by @option{-T} option, any file name beginning
+with @samp{-} character is considered a @command{tar} option and is
+processed accordingly.@footnote{Versions of @GNUTAR{} up to 1.15.1
+recognized only @option{-C} option in file lists, and only if the
+option and its argument occupied two consecutive lines.} For example,
+the common use of this feature is to change to another directory by
+specifying @option{-C} option:
-To restore files that were archived using a scripted backup, use the
-@code{restore} script. Its usage is quite straightforward. In the
-simplest form, invoke @code{restore --all}, it will
-then restore all the file systems and files specified in
-@file{backup-specs} (@pxref{General-Purpose Variables,BACKUP_DIRS}).
+@smallexample
+@group
+$ @kbd{cat list}
+-C/etc
+passwd
+hosts
+-C/lib
+libc.a
+$ @kbd{tar -c -f foo.tar --files-from list}
+@end group
+@end smallexample
-You may select the file systems (and/or files) to restore by
-giving @code{restore} list of @dfn{patterns} in its command
-line. For example, running
+@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
+contain:
@smallexample
-restore 'albert:*'
+@group
+$ @kbd{tar tf foo.tar}
+passwd
+hosts
+libc.a
+@end group
@end smallexample
@noindent
-will restore all file systems on the machine @samp{albert}. A more
-complicated example:
+@xopindex{directory, using in @option{--files-from} argument}
+Notice that the option parsing algorithm used with @option{-T} is
+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}.
+
+@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}.
+
+@item
+For both short and long option forms, the option argument can be given
+on the next line after the option name, e.g.:
@smallexample
-restore 'albert:*' '*:/var'
+@group
+--directory
+dir
+@end group
@end smallexample
@noindent
-This command will restore all file systems on the machine @samp{albert}
-as well as @file{/var} file system on all machines.
-
-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,
-use @option{--level} option, as shown in the example below:
+and
@smallexample
-restore --level=1
+@group
+-C
+dir
+@end group
@end smallexample
+@end itemize
-The full list of options accepted by @code{restore} follows:
-
-@table @option
-@item -a
-@itemx --all
-Restore all file systems and files specified in @file{backup-specs}
+@opindex 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}.
-@item -l @var{level}
-@itemx --level=@var{level}
-Start restoring from the given backup level, instead of the default 0.
+@menu
+* nul::
+@end menu
-@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}
-is 100, which means the highest debugging level.
+@node nul
+@subsection @code{NUL} Terminated File Names
-@item -h
-@itemx --help
-Display short help message and exit.
+@cindex File names, terminated by @code{NUL}
+@cindex @code{NUL} terminated file names
+The @option{--null} option causes
+@option{--files-from=@var{file-of-names}} (@option{-T @var{file-of-names}})
+to read file names terminated by a @code{NUL} instead of a newline, so
+files whose names contain newlines can be archived using
+@option{--files-from}.
-@item -V
-@itemx --version
-Display information about the program's name, version, origin and legal
-status, all on standard output, and then exit successfully.
+@table @option
+@opindex null
+@item --null
+Only consider @code{NUL} terminated file names, instead of files that
+terminate in a newline.
@end table
-You should start the restore script with the media containing the
-first volume of the archive mounted. The script will prompt for other
-volumes as they are needed. If the archive is on tape, you don't need
-to rewind the tape to to its beginning---if the tape head is
-positioned past the beginning of the archive, the script will rewind
-the tape as needed. @FIXME-xref{Media, for a discussion of tape
-positioning.}
-
-@quotation
-@strong{Warning:} The script will delete files from the active file
-system if they were not in the file system when the archive was made.
-@end quotation
-
-@xref{Incremental Dumps}, for an explanation of how the script makes
-that determination.
-
-@node Choosing
-@chapter Choosing Files and Names for @command{tar}
-@UNREVISED
+The @option{--null} option is just like the one in @acronym{GNU}
+@command{xargs} and @command{cpio}, and is useful with the
+@option{-print0} predicate of @acronym{GNU} @command{find}. In
+@command{tar}, @option{--null} also disables special handling for
+file names that begin with dash.
-Certain options to @command{tar} enable you to specify a name for your
-archive. Other options let you decide which files to include or exclude
-from the archive, based on when or whether files were modified, whether
-the file names do or don't match specified patterns, or whether files
-are in specified directories.
+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
+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
+files from that file, @file{long-files}, to create the archive
+@file{big.tgz}. The @option{--null} option to @command{tar} will cause
+@command{tar} to recognize the @code{NUL} separator between files.
-This chapter discusses these options in detail.
+@smallexample
+$ @kbd{find . -size +800 -print0 > long-files}
+$ @kbd{tar -c -v --null --files-from=long-files --file=big.tar}
+@end smallexample
-@menu
-* file:: Choosing the Archive's Name
-* Selecting Archive Members::
-* files:: Reading Names from a File
-* exclude:: Excluding Some Files
-* Wildcards:: Wildcards Patterns and Matching
-* after:: Operating Only on New Files
-* recurse:: Descending into Directories
-* one:: Crossing File System Boundaries
-@end menu
+@FIXME{say anything else here to conclude the section?}
-@node file
-@section Choosing and Naming Archive Files
+@node exclude
+@section Excluding Some Files
@UNREVISED
-@cindex Naming an archive
-@cindex Archive Name
-@cindex Choosing an archive file
-@cindex Where is the archive?
-By default, @command{tar} uses an archive file name that was compiled when
-it was built on the system; usually this name refers to some physical
-tape drive on the machine. However, the person who installed @command{tar}
-on the system may not have set the default to a meaningful value as far as
-most users are concerned. As a result, you will usually want to tell
-@command{tar} where to find (or create) the archive. The
-@option{--file=@var{archive-name}} (@option{-f @var{archive-name}})
-option allows you to either specify or name a file to use as the archive
-instead of the default archive file location.
+@cindex File names, excluding files by
+@cindex Excluding files by name and pattern
+@cindex Excluding files by file system
+To avoid operating on files whose names match a particular pattern,
+use the @option{--exclude} or @option{--exclude-from} options.
@table @option
-@opindex file, short description
-@item --file=@var{archive-name}
-@itemx -f @var{archive-name}
-Name the archive to create or operate on. Use in conjunction with
-any operation.
+@opindex exclude
+@item --exclude=@var{pattern}
+Causes @command{tar} to ignore files that match the @var{pattern}.
@end table
-For example, in this @command{tar} command,
+@findex exclude
+The @option{--exclude=@var{pattern}} option prevents any file or
+member whose name matches the shell wildcard (@var{pattern}) from
+being operated on.
+For example, to create an archive with all the contents of the directory
+@file{src} except for files whose names end in @file{.o}, use the
+command @samp{tar -cf src.tar --exclude='*.o' src}.
-@smallexample
-$ @kbd{tar -cvf collection.tar blues folk jazz}
-@end smallexample
+You may give multiple @option{--exclude} options.
-@noindent
-@file{collection.tar} is the name of the archive. It must directly
-follow the @option{-f} option, since whatever directly follows @option{-f}
-@emph{will} end up naming the archive. If you neglect to specify an
-archive name, you may end up overwriting a file in the working directory
-with the archive you create since @command{tar} will use this file's name
-for the archive name.
+@table @option
+@opindex exclude-from
+@item --exclude-from=@var{file}
+@itemx -X @var{file}
+Causes @command{tar} to ignore files that match the patterns listed in
+@var{file}.
+@end table
-An archive can be saved as a file in the file system, sent through a
-pipe or over a network, or written to an I/O device such as a tape,
-floppy disk, or CD write drive.
+@findex exclude-from
+Use the @option{--exclude-from} option to read a
+list of patterns, one per line, from @var{file}; @command{tar} will
+ignore files matching those patterns. Thus if @command{tar} is
+called as @w{@samp{tar -c -X foo .}} and the file @file{foo} contains a
+single line @file{*.o}, no files whose names end in @file{.o} will be
+added to the archive.
-@cindex Writing new archives
-@cindex Archive creation
-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}).
+@table @option
+@opindex exclude-caches
+@item --exclude-caches
+Causes @command{tar} to ignore directories containing a cache directory tag.
+@end table
-@cindex Standard input and output
-@cindex tar to standard input and output
-If you use @file{-} as an @var{archive-name}, @command{tar} reads the
-archive from standard input (when listing or extracting files), or
-writes it to standard output (when creating an archive). If you use
-@file{-} as an @var{archive-name} when modifying an archive,
-@command{tar} reads the original archive from its standard input and
-writes the entire new archive to its standard output.
+@findex exclude-caches
+When creating an archive, the @option{--exclude-caches} option causes
+@command{tar} to exclude all directories that contain a @dfn{cache
+directory tag}. A cache directory tag is a short file with the
+well-known name @file{CACHEDIR.TAG} and having a standard header
+specified in @url{http://www.brynosaurus.com/cachedir/spec.html}.
+Various applications write cache directory tags into directories they
+use to hold regenerable, non-precious data, so that such data can be
+more easily excluded from backups.
-The following example is a convenient way of copying directory
-hierarchy from @file{sourcedir} to @file{targetdir}.
+@menu
+* problems with exclude::
+@end menu
-@smallexample
-$ @kbd{(cd sourcedir; tar -cf - .) | (cd targetdir; tar -xpf -)}
-@end smallexample
+@node problems with exclude
+@unnumberedsubsec Problems with Using the @code{exclude} Options
-The @option{-C} option allows to avoid using subshells:
+@xopindex{exclude, potential problems with}
+Some users find @samp{exclude} options confusing. Here are some common
+pitfalls:
-@smallexample
-$ @kbd{tar -C sourcedir -cf - . | tar -C targetdir -xpf -}
-@end smallexample
+@itemize @bullet
+@item
+The main operating mode of @command{tar} does not act on a path name
+explicitly listed on the command line if one of its file name
+components is excluded. In the example above, if
+you create an archive and exclude files that end with @samp{*.o}, but
+explicitly name the file @samp{dir.o/foo} after all the options have been
+listed, @samp{dir.o/foo} will be excluded from the archive.
-In both examples above, the leftmost @command{tar} invocation archives
-the contents of @file{sourcedir} to the standard output, while the
-rightmost one reads this archive from its standard input and
-extracts it. The @option{-p} option tells it to restore permissions
-of the extracted files.
+@item
+You can sometimes confuse the meanings of @option{--exclude} and
+@option{--exclude-from}. Be careful: use @option{--exclude} when files
+to be excluded are given as a pattern on the command line. Use
+@option{--exclude-from} to introduce the name of a file which contains
+a list of patterns, one per line; each of these patterns can exclude
+zero, one, or many files.
-@cindex Remote devices
-@cindex tar to a remote device
-@anchor{remote-dev}
-To specify an archive file on a device attached to a remote machine,
-use the following:
+@item
+When you use @option{--exclude=@var{pattern}}, be sure to quote the
+@var{pattern} parameter, so @GNUTAR{} sees wildcard characters
+like @samp{*}. If you do not do this, the shell might expand the
+@samp{*} itself using files at hand, so @command{tar} might receive a
+list of files instead of one pattern, or none at all, making the
+command somewhat illegal. This might not correspond to what you want.
+
+For example, write:
@smallexample
-@kbd{--file=@var{hostname}:/@var{dev}/@var{file-name}}
+$ @kbd{tar -c -f @var{archive.tar} --exclude '*.o' @var{directory}}
@end smallexample
@noindent
-@command{tar} will complete the remote connection, if possible, and
-prompt you for a username and password. If you use
-@option{--file=@@@var{hostname}:/@var{dev}/@var{file-name}}, @command{tar}
-will complete the remote connection, if possible, using your username
-as the username on the remote machine.
-
-@cindex Local and remote archives
-@anchor{local and remote archives}
-If the archive file name includes a colon (@samp{:}), then it is assumed
-to be a file on another machine. If the archive file is
-@samp{@var{user}@@@var{host}:@var{file}}, then @var{file} is used on the
-host @var{host}. The remote host is accessed using the @command{rsh}
-program, with a username of @var{user}. If the username is omitted
-(along with the @samp{@@} sign), then your user name will be used.
-(This is the normal @command{rsh} behavior.) It is necessary for the
-remote machine, in addition to permitting your @command{rsh} access, to
-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
-colon, then the remote tape drive behavior
-can be inhibited by using the @option{--force-local} option.
-
-When the archive is being created to @file{/dev/null}, @GNUTAR{}
-tries to minimize input and output operations. The Amanda backup
-system, when used with @GNUTAR{}, has an initial sizing pass which
-uses this feature.
-
-@node Selecting Archive Members
-@section Selecting Archive Members
-@cindex Specifying files to act on
-@cindex Specifying archive members
-
-@dfn{File Name arguments} specify which files in the file system
-@command{tar} operates on, when creating or adding to an archive, or which
-archive members @command{tar} operates on, when reading or deleting from
-an archive. @xref{Operations}.
+rather than:
-To specify file names, you can include them as the last arguments on
-the command line, as follows:
@smallexample
-@kbd{tar} @var{operation} [@var{option1} @var{option2} @dots{}] [@var{file name-1} @var{file name-2} @dots{}]
+# @emph{Wrong!}
+$ @kbd{tar -c -f @var{archive.tar} --exclude *.o @var{directory}}
@end smallexample
-If a file name begins with dash (@samp{-}), precede it with
-@option{--add-file} option to prevent it from being treated as an
-option.
+@item
+You must use use shell syntax, or globbing, rather than @code{regexp}
+syntax, when using exclude options in @command{tar}. If you try to use
+@code{regexp} syntax to describe files to be excluded, your command
+might fail.
-If you specify a directory name as a file name argument, all the files
-in that directory are operated on by @command{tar}.
+@item
+@FIXME{The change in semantics must have occurred before 1.11,
+so I doubt if it is worth mentioning at all. Anyway, should at
+least specify in which version the semantics changed.}
+In earlier versions of @command{tar}, what is now the
+@option{--exclude-from} option was called @option{--exclude} instead.
+Now, @option{--exclude} applies to patterns listed on the command
+line and @option{--exclude-from} applies to patterns listed in a
+file.
-If you do not specify files, @command{tar} behavior differs depending
-on the operation mode as described below:
+@end itemize
-When @command{tar} is invoked with @option{--create} (@option{-c}),
-@command{tar} will stop immediately, reporting the following:
+@node wildcards
+@section Wildcards Patterns and Matching
-@smallexample
-@group
-$ @kbd{tar cf a.tar}
-tar: Cowardly refusing to create an empty archive
-Try `tar --help' or `tar --usage' for more information.
-@end group
-@end smallexample
+@dfn{Globbing} is the operation by which @dfn{wildcard} characters,
+@samp{*} or @samp{?} for example, are replaced and expanded into all
+existing files matching the given pattern. @GNUTAR{} can use wildcard
+patterns for matching (or globbing) archive members when extracting
+from or listing an archive. Wildcard patterns are also used for
+verifying volume labels of @command{tar} archives. This section has the
+purpose of explaining wildcard syntax for @command{tar}.
-If you specify either @option{--list} (@option{-t}) or
-@option{--extract} (@option{--get}, @option{-x}), @command{tar}
-operates on all the archive members in the archive.
+@FIXME{the next few paragraphs need work.}
-If run with @option{--diff} option, tar will compare the archive with
-the contents of the current working directory.
+A @var{pattern} should be written according to shell syntax, using wildcard
+characters to effect globbing. Most characters in the pattern stand
+for themselves in the matched string, and case is significant: @samp{a}
+will match only @samp{a}, and not @samp{A}. The character @samp{?} in the
+pattern matches any single character in the matched string. The character
+@samp{*} in the pattern matches zero, one, or more single characters in
+the matched string. The character @samp{\} says to take the following
+character of the pattern @emph{literally}; it is useful when one needs to
+match the @samp{?}, @samp{*}, @samp{[} or @samp{\} characters, themselves.
-If you specify any other operation, @command{tar} does nothing.
+The character @samp{[}, up to the matching @samp{]}, introduces a character
+class. A @dfn{character class} is a list of acceptable characters
+for the next single character of the matched string. For example,
+@samp{[abcde]} would match any of the first five letters of the alphabet.
+Note that within a character class, all of the ``special characters''
+listed above other than @samp{\} lose their special meaning; for example,
+@samp{[-\\[*?]]} would match any of the characters, @samp{-}, @samp{\},
+@samp{[}, @samp{*}, @samp{?}, or @samp{]}. (Due to parsing constraints,
+the characters @samp{-} and @samp{]} must either come @emph{first} or
+@emph{last} in a character class.)
-By default, @command{tar} takes file names from the command line. However,
-there are other ways to specify file or member names, or to modify the
-manner in which @command{tar} selects the files or members upon which to
-operate. In general, these methods work both for specifying the names
-of files and archive members.
+@cindex Excluding characters from a character class
+@cindex Character class, excluding characters from
+If the first character of the class after the opening @samp{[}
+is @samp{!} or @samp{^}, then the meaning of the class is reversed.
+Rather than listing character to match, it lists those characters which
+are @emph{forbidden} as the next single character of the matched string.
-@node files
-@section Reading Names from a File
+Other characters of the class stand for themselves. The special
+construction @samp{[@var{a}-@var{e}]}, using an hyphen between two
+letters, is meant to represent all characters between @var{a} and
+@var{e}, inclusive.
-@cindex Reading file names from a file
-@cindex Lists of file names
-@cindex File Name arguments, alternatives
-Instead of giving the names of files or archive members on the command
-line, you can put the names into a file, and then use the
-@option{--files-from=@var{file-of-names}} (@option{-T
-@var{file-of-names}}) 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
-the list of files to archive with the @command{find} utility.
+@FIXME{need to add a sentence or so here to make this clear for those
+who don't have dan around.}
-@table @option
-@opindex files-from
-@item --files-from=@var{file-name}
-@itemx -T @var{file-name}
-Get names to extract or create from file @var{file-name}.
-@end table
+Periods (@samp{.}) or forward slashes (@samp{/}) are not considered
+special for wildcard matches. However, if a pattern completely matches
+a directory prefix of a matched string, then it matches the full matched
+string: thus, excluding a directory also excludes all the files beneath it.
-If you give a single dash as a file name for @option{--files-from}, (i.e.,
-you specify either @code{--files-from=-} or @code{-T -}), then the file
-names are read from standard input.
+@menu
+* controlling pattern-matching::
+@end menu
-Unless you are running @command{tar} with @option{--create}, you can not use
-both @code{--files-from=-} and @code{--file=-} (@code{-f -}) in the same
-command.
+@node controlling pattern-matching
+@unnumberedsubsec Controlling Pattern-Matching
-Any number of @option{-T} options can be given in the command line.
+For the purposes of this section, we call @dfn{exclusion members} all
+member names obtained while processing @option{--exclude} and
+@option{--exclude-from} options, and @dfn{inclusion members} those
+member names that were given in the command line or read from the file
+specified with @option{--files-from} option.
-The following example shows how to use @command{find} to generate a list of
-files smaller than 400K in length and put that list into a file
-called @file{small-files}. You can then use the @option{-T} option to
-@command{tar} to specify the files from that file, @file{small-files}, to
-create the archive @file{little.tgz}. (The @option{-z} option to
-@command{tar} compresses the archive with @command{gzip}; @pxref{gzip} for
-more information.)
+These two pairs of member lists are used in the following operations:
+@option{--diff}, @option{--extract}, @option{--list},
+@option{--update}.
+
+There are no inclusion members in create mode (@option{--create} and
+@option{--append}), since in this mode the names obtained from the
+command line refer to @emph{files}, not archive members.
+
+By default, inclusion members are compared with archive members
+literally @footnote{Notice that earlier @GNUTAR{} versions used
+globbing for inclusion members, which contradicted to UNIX98
+specification and was not documented. @xref{Changes}, for more
+information on this and other changes.} and exclusion members are
+treated as globbing patterns. For example:
@smallexample
-$ @kbd{find . -size -400 -print > small-files}
-$ @kbd{tar -c -v -z -T small-files -f little.tgz}
+@group
+$ @kbd{tar tf foo.tar}
+a.c
+b.c
+a.txt
+[remarks]
+# @i{Member names are used verbatim:}
+$ @kbd{tar -xf foo.tar -v '[remarks]'}
+[remarks]
+# @i{Exclude member names are globbed:}
+$ @kbd{tar -xf foo.tar -v --exclude '*.c'}
+a.txt
+[remarks]
+@end group
@end smallexample
-@noindent
-In the file list given by @option{-T} option, any file name beginning
-with @samp{-} character is considered a @command{tar} option and is
-processed accordingly.@footnote{Versions of @GNUTAR{} up to 1.15.1
-recognized only @option{-C} option in file lists, and only if the
-option and its argument occupied two consecutive lines.} For example,
-the common use of this feature is to change to another directory by
-specifying @option{-C} option:
+This behavior can be altered by using the following options:
+
+@table @option
+@opindex wildcards
+@item --wildcards
+Treat all member names as wildcards.
+
+@opindex no-wildcards
+@item --no-wildcards
+Treat all member names as literal strings.
+@end table
+
+Thus, to extract files whose names end in @samp{.c}, you can use:
@smallexample
-@group
-$ @kbd{cat list}
--C/etc
-passwd
-hosts
--C/lib
-libc.a
-$ @kbd{tar -c -f foo.tar --files-from list}
-@end group
+$ @kbd{tar -xf foo.tar -v --wildcards '*.c'}
+a.c
+b.c
@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
-contain:
+Notice quoting of the pattern to prevent the shell from interpreting
+it.
+
+The effect of @option{--wildcards} option is cancelled by
+@option{--no-wildcards}. This can be used to pass part of
+the command line arguments verbatim and other part as globbing
+patterns. For example, the following invocation:
@smallexample
-@group
-$ @kbd{tar tf foo.tar}
-passwd
-hosts
-libc.a
-@end group
+$ @kbd{tar -xf foo.tar --wildcards '*.txt' --no-wildcards '[remarks]'}
@end smallexample
@noindent
-@opindex directory, using in @option{--files-from} argument
-Notice that the option parsing algorithm used with @option{-T} is
-stricter than the one used by shell. Namely, when specifying option
-arguments, you should observe the following rules:
+instructs @command{tar} to extract from @file{foo.tar} all files whose
+names end in @samp{.txt} and the file named @file{[remarks]}.
-@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}.
+Normally, a pattern matches a name if an initial subsequence of the
+name's components matches the pattern, where @samp{*}, @samp{?}, and
+@samp{[...]} are the usual shell wildcards, @samp{\} escapes wildcards,
+and wildcards can match @samp{/}.
-@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}.
+Other than optionally stripping leading @samp{/} from names
+(@pxref{absolute}), patterns and names are used as-is. For
+example, trailing @samp{/} is not trimmed from a user-specified name
+before deciding whether to exclude it.
-@item
-For both short and long option forms, the option argument can be given
-on the next line after the option name, e.g.:
+However, this matching procedure can be altered by the options listed
+below. These options accumulate. For example:
@smallexample
-@group
---directory
-dir
-@end group
+--ignore-case --exclude='makefile' --no-ignore-case ---exclude='readme'
@end smallexample
@noindent
-and
+ignores case when excluding @samp{makefile}, but not when excluding
+@samp{readme}.
-@smallexample
-@group
--C
-dir
-@end group
-@end smallexample
-@end itemize
+@table @option
+@opindex anchored
+@opindex no-anchored
+@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} for exclusion members
+and @option{--anchored} inclusion members.
-@opindex 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}.
+@opindex ignore-case
+@opindex no-ignore-case
+@item --ignore-case
+@itemx --no-ignore-case
+When ignoring case, upper-case patterns match lower-case names and vice versa.
+When not ignoring case (the default), matching is case-sensitive.
-@menu
-* nul::
-@end menu
+@opindex wildcards-match-slash
+@opindex no-wildcards-match-slash
+@item --wildcards-match-slash
+@itemx --no-wildcards-match-slash
+When wildcards match slash (the default for exclusion members), a
+wildcard like @samp{*} in the pattern can match a @samp{/} in the
+name. Otherwise, @samp{/} is matched only by @samp{/}.
-@node nul
-@subsection @code{NUL} Terminated File Names
+@end table
-@cindex File names, terminated by @code{NUL}
-@cindex @code{NUL} terminated file names
-The @option{--null} option causes
-@option{--files-from=@var{file-of-names}} (@option{-T @var{file-of-names}})
-to read file names terminated by a @code{NUL} instead of a newline, so
-files whose names contain newlines can be archived using
-@option{--files-from}.
+The @option{--recursion} and @option{--no-recursion} options
+(@pxref{recurse}) also affect how member patterns are interpreted. If
+recursion is in effect, a pattern matches a name if it matches any of
+the name's parent directories.
-@table @option
-@opindex null
-@item --null
-Only consider @code{NUL} terminated file names, instead of files that
-terminate in a newline.
-@end table
+The following table summarizes pattern-matching default values:
-The @option{--null} option is just like the one in @acronym{GNU}
-@command{xargs} and @command{cpio}, and is useful with the
-@option{-print0} predicate of @acronym{GNU} @command{find}. In
-@command{tar}, @option{--null} also disables special handling for
-file names that begin with dash.
+@multitable @columnfractions .3 .7
+@headitem Members @tab Default settings
+@item Inclusion @tab @option{--no-wildcards --anchored --no-wildcards-match-slash}
+@item Exclusion @tab @option{--wildcards --no-anchored --wildcards-match-slash}
+@end multitable
-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
-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
-files from that file, @file{long-files}, to create the archive
-@file{big.tgz}. The @option{--null} option to @command{tar} will cause
-@command{tar} to recognize the @code{NUL} separator between files.
+@node quoting styles
+@section Quoting Member Names
-@smallexample
-$ @kbd{find . -size +800 -print0 > long-files}
-$ @kbd{tar -c -v --null --files-from=long-files --file=big.tar}
-@end smallexample
+When displaying member names, @command{tar} takes care to avoid
+ambiguities caused by certain characters. This is called @dfn{name
+quoting}. The characters in question are:
-@FIXME{say anything else here to conclude the section?}
+@itemize @bullet
+@item Non-printable control characters:
-@node exclude
-@section Excluding Some Files
-@UNREVISED
+@multitable @columnfractions 0.20 0.10 0.60
+@headitem Character @tab ASCII @tab Character name
+@item \a @tab 7 @tab Audible bell
+@item \b @tab 8 @tab Backspace
+@item \f @tab 12 @tab Form feed
+@item \n @tab 10 @tab New line
+@item \r @tab 13 @tab Carriage return
+@item \t @tab 9 @tab Horizontal tabulation
+@item \v @tab 11 @tab Vertical tabulation
+@end multitable
-@cindex File names, excluding files by
-@cindex Excluding files by name and pattern
-@cindex Excluding files by file system
-To avoid operating on files whose names match a particular pattern,
-use the @option{--exclude} or @option{--exclude-from} options.
+@item Space (ASCII 32)
-@table @option
-@opindex exclude
-@item --exclude=@var{pattern}
-Causes @command{tar} to ignore files that match the @var{pattern}.
-@end table
+@item Single and double quotes (@samp{'} and @samp{"})
-@findex exclude
-The @option{--exclude=@var{pattern}} option prevents any file or
-member whose name matches the shell wildcard (@var{pattern}) from
-being operated on.
-For example, to create an archive with all the contents of the directory
-@file{src} except for files whose names end in @file{.o}, use the
-command @samp{tar -cf src.tar --exclude='*.o' src}.
+@item Backslash (@samp{\})
+@end itemize
-You may give multiple @option{--exclude} options.
+The exact way @command{tar} uses to quote these characters depends on
+the @dfn{quoting style}. The default quoting style, called
+@dfn{escape} (see below), uses backslash notation to represent control
+characters, space and backslash. Using this quoting style, control
+characters are represented as listed in column @samp{Character} in the
+above table, a space is printed as @samp{\ } and a backslash as @samp{\\}.
+
+@GNUTAR{} offers seven distinct quoting styles, which can be selected
+using @option{--quoting-style} option:
@table @option
-@opindex exclude-from
-@item --exclude-from=@var{file}
-@itemx -X @var{file}
-Causes @command{tar} to ignore files that match the patterns listed in
-@var{file}.
+@item --quoting-style=@var{style}
+@opindex quoting-style
+
+Sets quoting style. Valid values for @var{style} argument are:
+literal, shell, shell-always, c, escape, locale, clocale.
@end table
-@findex exclude-from
-Use the @option{--exclude-from} option to read a
-list of patterns, one per line, from @var{file}; @command{tar} will
-ignore files matching those patterns. Thus if @command{tar} is
-called as @w{@samp{tar -c -X foo .}} and the file @file{foo} contains a
-single line @file{*.o}, no files whose names end in @file{.o} will be
-added to the archive.
+These styles are described in detail below. To illustrate their
+effect, we will use an imaginary tar archive @file{arch.tar}
+containing the following members:
+
+@smallexample
+@group
+# 1. Contains horizontal tabulation character.
+a tab
+# 2. Contains newline character
+a
+newline
+# 3. Contains a space
+a space
+# 4. Contains double quotes
+a"double"quote
+# 5. Contains single quotes
+a'single'quote
+# 6. Contains a backslash character:
+a\backslash
+@end group
+@end smallexample
+
+Here is how usual @command{ls} command would have listed them, if they
+had existed in the current working directory:
+
+@smallexample
+@group
+$ @kbd{ls}
+a\ttab
+a\nnewline
+a\ space
+a"double"quote
+a'single'quote
+a\\backslash
+@end group
+@end smallexample
-@table @option
-@opindex exclude-caches
-@item --exclude-caches
-Causes @command{tar} to ignore directories containing a cache directory tag.
-@end table
+Quoting styles:
-@findex exclude-caches
-When creating an archive, the @option{--exclude-caches} option causes
-@command{tar} to exclude all directories that contain a @dfn{cache
-directory tag}. A cache directory tag is a short file with the
-well-known name @file{CACHEDIR.TAG} and having a standard header
-specified in @url{http://www.brynosaurus.com/cachedir/spec.html}.
-Various applications write cache directory tags into directories they
-use to hold regenerable, non-precious data, so that such data can be
-more easily excluded from backups.
+@table @samp
+@item literal
+No quoting, display each character as is:
-@menu
-* problems with exclude::
-@end menu
+@smallexample
+@group
+$ @kbd{tar tf arch.tar --quoting-style=literal}
+./
+./a space
+./a'single'quote
+./a"double"quote
+./a\backslash
+./a tab
+./a
+newline
+@end group
+@end smallexample
-@node problems with exclude
-@unnumberedsubsec Problems with Using the @code{exclude} Options
+@item shell
+Display characters the same way Bourne shell does:
+control characters, except @samp{\t} and @samp{\n}, are printed using
+backslash escapes, @samp{\t} and @samp{\n} are printed as is, and a
+single quote is printed as @samp{\'}. If a name contains any quoted
+characters, it is enclosed in single quotes. In particular, if a name
+contains single quotes, it is printed as several single-quoted strings:
-@opindex exclude, potential problems with
-Some users find @samp{exclude} options confusing. Here are some common
-pitfalls:
+@smallexample
+@group
+$ @kbd{tar tf arch.tar --quoting-style=shell}
+./
+'./a space'
+'./a'\''single'\''quote'
+'./a"double"quote'
+'./a\backslash'
+'./a tab'
+'./a
+newline'
+@end group
+@end smallexample
-@itemize @bullet
-@item
-The main operating mode of @command{tar} does not act on a path name
-explicitly listed on the command line if one of its file name
-components is excluded. In the example above, if
-you create an archive and exclude files that end with @samp{*.o}, but
-explicitly name the file @samp{dir.o/foo} after all the options have been
-listed, @samp{dir.o/foo} will be excluded from the archive.
+@item shell-always
+Same as @samp{shell}, but the names are always enclosed in single
+quotes:
-@item
-You can sometimes confuse the meanings of @option{--exclude} and
-@option{--exclude-from}. Be careful: use @option{--exclude} when files
-to be excluded are given as a pattern on the command line. Use
-@option{--exclude-from} to introduce the name of a file which contains
-a list of patterns, one per line; each of these patterns can exclude
-zero, one, or many files.
+@smallexample
+@group
+$ @kbd{tar tf arch.tar --quoting-style=shell-always}
+'./'
+'./a space'
+'./a'\''single'\''quote'
+'./a"double"quote'
+'./a\backslash'
+'./a tab'
+'./a
+newline'
+@end group
+@end smallexample
-@item
-When you use @option{--exclude=@var{pattern}}, be sure to quote the
-@var{pattern} parameter, so @GNUTAR{} sees wildcard characters
-like @samp{*}. If you do not do this, the shell might expand the
-@samp{*} itself using files at hand, so @command{tar} might receive a
-list of files instead of one pattern, or none at all, making the
-command somewhat illegal. This might not correspond to what you want.
+@item c
+Use the notation of the C programming language. All names are
+enclosed in double quotes. Control characters are quoted using
+backslash notations, double quotes are represented as @samp{\"},
+backslash characters are represented as @samp{\\}. Single quotes and
+spaces are not quoted:
-For example, write:
+@smallexample
+@group
+$ @kbd{tar tf arch.tar --quoting-style=c}
+"./"
+"./a space"
+"./a'single'quote"
+"./a\"double\"quote"
+"./a\\backslash"
+"./a\ttab"
+"./a\nnewline"
+@end group
+@end smallexample
+
+@item escape
+Control characters are printed using backslash notation, a space is
+printed as @samp{\ } and a backslash as @samp{\\}. This is the
+default quoting style, unless it was changed when configured the
+package.
@smallexample
-$ @kbd{tar -c -f @var{archive.tar} --exclude '*.o' @var{directory}}
+@group
+$ @kbd{tar tf arch.tar --quoting-style=escape}
+./
+./a space
+./a'single'quote
+./a"double"quote
+./a\\backslash
+./a\ttab
+./a\nnewline
+@end group
@end smallexample
-@noindent
-rather than:
+@item locale
+Control characters, single quote and backslash are printed using
+backslash notation. All names are quoted using left and right
+quotation marks, appropriate to the current locale. If it does not
+define quotation marks, use @samp{`} as left and @samp{'} as right
+quotation marks. Any occurrences of the right quotation mark in a
+name are escaped with @samp{\}, for example:
+
+For example:
@smallexample
-# @emph{Wrong!}
-$ @kbd{tar -c -f @var{archive.tar} --exclude *.o @var{directory}}
+@group
+$ @kbd{tar tf arch.tar --quoting-style=locale}
+`./'
+`./a space'
+`./a\'single\'quote'
+`./a"double"quote'
+`./a\\backslash'
+`./a\ttab'
+`./a\nnewline'
+@end group
@end smallexample
-@item
-You must use use shell syntax, or globbing, rather than @code{regexp}
-syntax, when using exclude options in @command{tar}. If you try to use
-@code{regexp} syntax to describe files to be excluded, your command
-might fail.
+@item clocale
+Same as @samp{locale}, but @samp{"} is used for both left and right
+quotation marks, if not provided by the currently selected locale:
-@item
-@FIXME{The change in semantics must have occurred before 1.11,
-so I doubt if it is worth mentioning at all. Anyway, should at
-least specify in which version the semantics changed.}
-In earlier versions of @command{tar}, what is now the
-@option{--exclude-from} option was called @option{--exclude} instead.
-Now, @option{--exclude} applies to patterns listed on the command
-line and @option{--exclude-from} applies to patterns listed in a
-file.
+@smallexample
+@group
+$ @kbd{tar tf arch.tar --quoting-style=clocale}
+"./"
+"./a space"
+"./a'single'quote"
+"./a\"double\"quote"
+"./a\\backslash"
+"./a\ttab"
+"./a\nnewline"
+@end group
+@end smallexample
+@end table
-@end itemize
+You can specify which characters should be quoted in addition to those
+implied by the current quoting style:
-@node Wildcards
-@section Wildcards Patterns and Matching
+@table @option
+@item --quote-chars=@var{string}
+Always quote characters from @var{string}, even if the selected
+quoting style would not quote them.
+@end table
-@dfn{Globbing} is the operation by which @dfn{wildcard} characters,
-@samp{*} or @samp{?} for example, are replaced and expanded into all
-existing files matching the given pattern. @GNUTAR{} can use wildcard
-patterns for matching (or globbing) archive members when extracting
-from or listing an archive. Wildcard patterns are also used for
-verifying volume labels of @command{tar} archives. This section has the
-purpose of explaining wildcard syntax for @command{tar}.
+For example, using @samp{escape} quoting (compare with the usual
+escape listing above):
-@FIXME{the next few paragraphs need work.}
+@smallexample
+@group
+$ @kbd{tar tf arch.tar --quoting-style=escape --quote-chars=' "'}
+./
+./a\ space
+./a'single'quote
+./a\"double\"quote
+./a\\backslash
+./a\ttab
+./a\nnewline
+@end group
+@end smallexample
-A @var{pattern} should be written according to shell syntax, using wildcard
-characters to effect globbing. Most characters in the pattern stand
-for themselves in the matched string, and case is significant: @samp{a}
-will match only @samp{a}, and not @samp{A}. The character @samp{?} in the
-pattern matches any single character in the matched string. The character
-@samp{*} in the pattern matches zero, one, or more single characters in
-the matched string. The character @samp{\} says to take the following
-character of the pattern @emph{literally}; it is useful when one needs to
-match the @samp{?}, @samp{*}, @samp{[} or @samp{\} characters, themselves.
+To disable quoting of such additional characters, use the following
+option:
-The character @samp{[}, up to the matching @samp{]}, introduces a character
-class. A @dfn{character class} is a list of acceptable characters
-for the next single character of the matched string. For example,
-@samp{[abcde]} would match any of the first five letters of the alphabet.
-Note that within a character class, all of the ``special characters''
-listed above other than @samp{\} lose their special meaning; for example,
-@samp{[-\\[*?]]} would match any of the characters, @samp{-}, @samp{\},
-@samp{[}, @samp{*}, @samp{?}, or @samp{]}. (Due to parsing constraints,
-the characters @samp{-} and @samp{]} must either come @emph{first} or
-@emph{last} in a character class.)
+@table @option
+@item --no-quote-chars=@var{string}
+Remove characters listed in @var{string} from the list of quoted
+characters set by the previous @option{--quote-chars} option.
+@end table
-@cindex Excluding characters from a character class
-@cindex Character class, excluding characters from
-If the first character of the class after the opening @samp{[}
-is @samp{!} or @samp{^}, then the meaning of the class is reversed.
-Rather than listing character to match, it lists those characters which
-are @emph{forbidden} as the next single character of the matched string.
+This option is particularly useful if you have added
+@option{--quote-chars} to your @env{TAR_OPTIONS} (@pxref{TAR_OPTIONS})
+and wish to disable it for the current invocation.
+
+Note, that @option{--no-quote-chars} does @emph{not} disable those
+characters that are quoted by default in the selected quoting style.
-Other characters of the class stand for themselves. The special
-construction @samp{[@var{a}-@var{e}]}, using an hyphen between two
-letters, is meant to represent all characters between @var{a} and
-@var{e}, inclusive.
+@node transform
+@section Modifying File and Member Names
+
+@command{Tar} archives contain detailed information about files stored
+in them and full file names are part of that information. When
+storing file to an archive, its file name is recorded in the archive
+along with the actual file contents. When restoring from an archive,
+a file is created on disk with exactly the same name as that stored
+in the archive. In the majority of cases this is the desired behavior
+of a file archiver. However, there are some cases when it is not.
+
+First of all, it is often unsafe to extract archive members with
+absolute file names or those that begin with a @file{../}. @GNUTAR{}
+takes special precautions when extracting such names and provides a
+special option for handling them, which is described in
+@ref{absolute}.
+
+Secondly, you may wish to extract file names without some leading
+directory components, or with otherwise modified names. In other
+cases it is desirable to store files under differing names in the
+archive.
-@FIXME{need to add a sentence or so here to make this clear for those
-who don't have dan around.}
+@GNUTAR{} provides two options for these needs.
-Periods (@samp{.}) or forward slashes (@samp{/}) are not considered
-special for wildcard matches. However, if a pattern completely matches
-a directory prefix of a matched string, then it matches the full matched
-string: thus, excluding a directory also excludes all the files beneath it.
+@table @option
+@opindex strip-components
+@item --strip-components=@var{number}
+Strip given @var{number} of leading components from file names before
+extraction.
+@end table
-@menu
-* controlling pattern-matching::
-@end menu
+For example, suppose you have archived whole @file{/usr} hierarchy to
+a tar archive named @file{usr.tar}. Among other files, this archive
+contains @file{usr/include/stdlib.h}, which you wish to extract to
+the current working directory. To do so, you type:
-@node controlling pattern-matching
-@unnumberedsubsec Controlling Pattern-Matching
+@smallexample
+$ @kbd{tar -xf usr.tar --strip=2 usr/include/stdlib.h}
+@end smallexample
-For the purposes of this section, we call @dfn{exclusion members} all
-member names obtained while processing @option{--exclude} and
-@option{--exclude-from} options, and @dfn{inclusion members} those
-member names that were given in the command line or read from the file
-specified with @option{--files-from} option.
+The option @option{--strip=2} instructs @command{tar} to strip the
+two leading components (@file{usr/} and @file{include/}) off the file
+name.
-These two pairs of member lists are used in the following operations:
-@option{--diff}, @option{--extract}, @option{--list},
-@option{--update}.
+If you add to the above invocation @option{--verbose} (@option{-v})
+option, you will note that the verbose listing still contains the
+full file name, with the two removed components still in place. This
+can be inconvenient, so @command{tar} provides a special option for
+altering this behavior:
-There are no inclusion members in create mode (@option{--create} and
-@option{--append}), since in this mode the names obtained from the
-command line refer to @emph{files}, not archive members.
+@anchor{show-transformed-names}
+@table @option
+@opindex show-transformed-names
+@item --show-transformed-names
+Display file or member names with all requested transformations
+applied.
+@end table
-By default, inclusion members are compared with archive members
-literally @footnote{Notice that earlier @GNUTAR{} versions used
-globbing for inclusion members, which contradicted to UNIX98
-specification and was not documented. @xref{Changes}, for more
-information on this and other changes} and exclusion members are
-treated as globbing patterns. For example:
+@noindent
+For example:
@smallexample
@group
-$ @kbd{tar tf foo.tar}
-a.c
-b.c
-a.txt
-[remarks]
-# @i{Member names are used verbatim:}
-$ @kbd{tar -xf foo.tar -v '[remarks]'}
-[remarks]
-# @i{Exclude member names are globbed:}
-$ @kbd{tar -xf foo.tar -v --exclude '*.c'}
-a.txt
-[remarks]
+$ @kbd{tar -xf usr.tar -v --strip=2 usr/include/stdlib.h}
+usr/include/stdlib.h
+$ @kbd{tar -xf usr.tar -v --strip=2 --show-transformed usr/include/stdlib.h}
+stdlib.h
@end group
@end smallexample
-This behavior can be altered by using the following options:
+Notice that in both cases the file is @file{stdlib.h} extracted to the
+current working directory, @option{--show-transformed-names} affects
+only the way its name is displayed.
-@table @option
-@opindex wildcards
-@item --wildcards
-Treat all member names as wildcards.
+This option is especially useful for verifying whether the invocation
+will have the desired effect. Thus, before running
-@opindex no-wildcards
-@item --no-wildcards
-Treat all member names as literal strings.
-@end table
+@smallexample
+$ @kbd{tar -x --strip=@var{n}}
+@end smallexample
-Thus, to extract files whose names end in @samp{.c}, you can use:
+@noindent
+it is often advisable to run
@smallexample
-$ @kbd{tar -xf foo.tar -v --wildcards '*.c'}
-a.c
-b.c
+$ @kbd{tar -t -v --show-transformed --strip=@var{n}}
@end smallexample
@noindent
-Notice quoting of the pattern to prevent the shell from interpreting
-it.
+to make sure the command will produce the intended results.
-The effect of @option{--wildcards} option is cancelled by
-@option{--no-wildcards}. This can be used to pass part of
-the command line arguments verbatim and other part as globbing
-patterns. For example, the following invocation:
+In case you need to apply more complex modifications to the file name,
+@GNUTAR{} provides a general-purpose transformation option:
+
+@table @option
+@opindex transform
+@item --transform=@var{expression}
+Modify file names using supplied @var{expression}.
+@end table
+
+@noindent
+The @var{expression} is a @command{sed}-like replace expression of the
+form:
@smallexample
-$ @kbd{tar -xf foo.tar --wildcards '*.txt' --no-wildcards '[remarks]'}
+s/@var{regexp}/@var{replace}/[@var{flags}]
@end smallexample
@noindent
-instructs @command{tar} to extract from @file{foo.tar} all files whose
-names end in @samp{.txt} and the file named @file{[remarks]}.
+where @var{regexp} is a @dfn{regular expression}, @var{replace} is a
+replacement for each file name part that matches @var{regexp}. Both
+@var{regexp} and @var{replace} are described in detail in
+@ref{The "s" Command, The "s" Command, The `s' Command, sed, GNU sed}.
-Normally, a pattern matches a name if an initial subsequence of the
-name's components matches the pattern, where @samp{*}, @samp{?}, and
-@samp{[...]} are the usual shell wildcards, @samp{\} escapes wildcards,
-and wildcards can match @samp{/}.
+Supported @var{flags} are:
-Other than optionally stripping leading @samp{/} from names
-(@pxref{absolute}), patterns and names are used as-is. For
-example, trailing @samp{/} is not trimmed from a user-specified name
-before deciding whether to exclude it.
+@table @samp
+@item g
+Apply the replacement to @emph{all} matches to the @var{regexp}, not
+just the first.
+
+@item i
+Use case-insensitive matching
+
+@item x
+@var{regexp} is an @dfn{extended regular expression} (@pxref{Extended
+regexps, Extended regular expressions, Extended regular expressions,
+sed, GNU sed}).
+
+@item @var{number}
+Only replace the @var{number}th match of the @var{regexp}.
+
+Note: the @var{posix} standard does not specify what should happen
+when you mix the @samp{g} and @var{number} modifiers. @GNUTAR{}
+follows the GNU @command{sed} implementation in this regard, so
+the the interaction is defined to be: ignore matches before the
+@var{number}th, and then match and replace all matches from the
+@var{number}th on.
+
+@end table
-However, this matching procedure can be altered by the options listed
-below. These options accumulate. For example:
+Any delimiter can be used in lieue of @samp{/}, the only requirement being
+that it be used consistently throughout the expression. For example,
+the following two expressions are equivalent:
@smallexample
---ignore-case --exclude='makefile' --no-ignore-case ---exclude='readme'
+@group
+s/one/two/
+s,one,two,
+@end group
@end smallexample
-ignores case when excluding @samp{makefile}, but not when excluding
-@samp{readme}.
+Changing delimiters is often useful when the @var{regex} contains
+slashes. For example, it is more convenient to write @code{s,/,-,} than
+@code{s/\//-/}.
-@table @option
-@opindex anchored
-@opindex no-anchored
-@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} for exclusion members
-and @option{--anchored} inclusion members.
+Here are several examples of @option{--transform} usage:
-@opindex ignore-case
-@opindex no-ignore-case
-@item --ignore-case
-@itemx --no-ignore-case
-When ignoring case, upper-case patterns match lower-case names and vice versa.
-When not ignoring case (the default), matching is case-sensitive.
+@enumerate
+@item Extract @file{usr/} hierarchy into @file{usr/local/}:
-@opindex wildcards-match-slash
-@opindex no-wildcards-match-slash
-@item --wildcards-match-slash
-@itemx --no-wildcards-match-slash
-When wildcards match slash (the default for exclusion members), a
-wildcard like @samp{*} in the pattern can match a @samp{/} in the
-name. Otherwise, @samp{/} is matched only by @samp{/}.
+@smallexample
+$ @kbd{tar --transform='s,usr/,usr/local/,' -x -f arch.tar}
+@end smallexample
-@end table
+@item Strip two leading directory components (equivalent to
+@option{--strip-components=2}):
-The @option{--recursion} and @option{--no-recursion} options
-(@pxref{recurse}) also affect how member patterns are interpreted. If
-recursion is in effect, a pattern matches a name if it matches any of
-the name's parent directories.
+@smallexample
+$ @kbd{tar --transform='s,/*[^/]*/[^/]*/,,' -x -f arch.tar}
+@end smallexample
-The following table summarizes pattern-matching default values:
+@item Prepend @file{/prefix/} to each file name:
-@multitable @columnfractions .3 .7
-@headitem Members @tab Default settings
-@item Inclusion @tab @option{--no-wildcards --anchored --no-wildcards-match-slash}
-@item Exclusion @tab @option{--wildcards --no-anchored --wildcards-match-slash}
-@end multitable
+@smallexample
+$ @kbd{tar --transform 's,^,/prefix/,' -x -f arch.tar}
+@end smallexample
+
+@item Convert each file name to lower case:
+
+@smallexample
+$ @kbd{tar --transform 's/.*/\L&/' -x -f arch.tar}
+@end smallexample
+
+@end enumerate
+
+Unlike @option{--strip-components}, @option{--transform} can be used
+in any @GNUTAR{} operation mode. For example, the following command
+adds files to the archive while replacing the leading @file{usr/}
+component with @file{var/}:
+
+@smallexample
+$ @kbd{tar -cf arch.tar --transform='s,^usr/,var/,' /}
+@end smallexample
+To test @option{--transform} effect we suggest using
+@option{--show-transformed-names} option:
+
+@smallexample
+$ @kbd{tar -cf arch.tar --transform='s,^usr/,var/,' \
+ --verbose --show-transformed-names /}
+@end smallexample
+
+If both @option{--strip-components} and @option{--transform} are used
+together, then @option{--transform} is applied first, and the required
+number of components is then stripped from its result.
+
@node after
@section Operating Only on New Files
@UNREVISED
* Portability:: Making @command{tar} Archives More Portable
* Compression:: Using Less Space through Compression
* Attributes:: Handling File Attributes
-* Standard:: The Standard Format
-* Extensions:: @acronym{GNU} Extensions to the Archive Format
* cpio:: Comparison of @command{tar} and @command{cpio}
@end menu
contiguous files, and device files, and specifies file ownership by
group and user IDs instead of group and user names.
-When updating an archive, do not use @option{--format=v7}
-unless the archive was created using this option.
+When updating an archive, do not use @option{--format=v7}
+unless the archive was created using this option.
+
+In most cases, a @emph{new} format archive can be read by an @emph{old}
+@command{tar} program without serious trouble, so this option should
+seldom be needed. On the other hand, most modern @command{tar}s are
+able to read old format archives, so it might be safer for you to
+always use @option{--format=v7} for your distributions.
+
+@node ustar
+@subsection Ustar Archive Format
+
+@cindex 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
+still has many restrictions (@xref{Formats,ustar}, for the detailed
+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}.
+
+To create archive in @code{ustar} format, use @option{--format=ustar}
+option in conjunction with the @option{--create} (@option{-c}).
+
+@node gnu
+@subsection @acronym{GNU} and old @GNUTAR{} format
+
+@cindex GNU archive format
+@cindex Old GNU archive format
+@GNUTAR{} was based on an early draft of the
+@acronym{POSIX} 1003.1 @code{ustar} standard. @acronym{GNU} extensions to
+@command{tar}, such as the support for file names longer than 100
+characters, use portions of the @command{tar} header record which were
+specified in that @acronym{POSIX} draft as unused. Subsequent changes in
+@acronym{POSIX} have allocated the same parts of the header record for
+other purposes. As a result, @GNUTAR{} format is
+incompatible with the current @acronym{POSIX} specification, and with
+@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
+we plan to make @samp{posix} format the default.
+
+To force creation a @GNUTAR{} archive, use option
+@option{--format=gnu}.
+
+@node posix
+@subsection @GNUTAR{} and @acronym{POSIX} @command{tar}
+
+@cindex POSIX archive format
+@cindex PAX archive format
+Starting from version 1.14 @GNUTAR{} features full support for
+@acronym{POSIX.1-2001} archives.
+
+A @acronym{POSIX} conformant archive will be created if @command{tar}
+was given @option{--format=posix} (@option{--format=pax}) option. No
+special option is required to read and extract from a @acronym{POSIX}
+archive.
+
+@menu
+* PAX keywords:: Controlling Extended Header Keywords.
+@end menu
+
+@node PAX keywords
+@subsubsection Controlling Extended Header Keywords
+
+@table @option
+@opindex pax-option
+@item --pax-option=@var{keyword-list}
+Handle keywords in @acronym{PAX} extended headers. This option is
+equivalent to @option{-o} option of the @command{pax} utility.
+@end table
+
+@var{Keyword-list} is a comma-separated
+list of keyword options, each keyword option taking one of
+the following forms:
+
+@table @code
+@item delete=@var{pattern}
+When used with one of archive-creation commands,
+this option instructs @command{tar} to omit from extended header records
+that it produces any keywords matching the string @var{pattern}.
+
+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
+matching notation described in @acronym{POSIX 1003.2}, 3.13
+(@pxref{wildcards}). For example:
+
+@smallexample
+--pax-option delete=security.*
+@end smallexample
+
+would suppress security-related information.
+
+@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
+from @var{string} after making the following substitutions:
+
+@multitable @columnfractions .25 .55
+@headitem Meta-character @tab Replaced By
+@item %d @tab The directory name of the file, equivalent to the
+result of the @command{dirname} utility on the translated pathname.
+@item %f @tab The filename of the file, equivalent to the result
+of the @command{basename} utility on the translated pathname.
+@item %p @tab The process ID of the @command{tar} process.
+@item %% @tab A @samp{%} character.
+@end multitable
+
+Any other @samp{%} characters in @var{string} produce undefined
+results.
+
+If no option @samp{exthdr.name=string} is specified, @command{tar}
+will use the following default value:
+
+@smallexample
+%d/PaxHeaders.%p/%f
+@end smallexample
-In most cases, a @emph{new} format archive can be read by an @emph{old}
-@command{tar} program without serious trouble, so this option should
-seldom be needed. On the other hand, most modern @command{tar}s are
-able to read old format archives, so it might be safer for you to
-always use @option{--format=v7} for your distributions.
+@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
+is obtained from the contents of @var{string}, after making
+the following substitutions:
-@node ustar
-@subsection Ustar Archive Format
+@multitable @columnfractions .25 .55
+@headitem Meta-character @tab Replaced By
+@item %n @tab An integer that represents the
+sequence number of the global extended header record in the archive,
+starting at 1.
+@item %p @tab The process ID of the @command{tar} process.
+@item %% @tab A @samp{%} character.
+@end multitable
-@cindex 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
-still has many restrictions (@xref{Formats,ustar}, for the detailed
-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}.
+Any other @samp{%} characters in @var{string} produce undefined results.
-To create archive in @code{ustar} format, use @option{--format=ustar}
-option in conjunction with the @option{--create} (@option{-c}).
+If no option @samp{globexthdr.name=string} is specified, @command{tar}
+will use the following default value:
-@node gnu
-@subsection @acronym{GNU} and old @GNUTAR{} format
+@smallexample
+$TMPDIR/GlobalHead.%p.%n
+@end smallexample
-@cindex GNU archive format
-@cindex Old GNU archive format
-@GNUTAR{} was based on an early draft of the
-@acronym{POSIX} 1003.1 @code{ustar} standard. @acronym{GNU} extensions to
-@command{tar}, such as the support for file names longer than 100
-characters, use portions of the @command{tar} header record which were
-specified in that @acronym{POSIX} draft as unused. Subsequent changes in
-@acronym{POSIX} have allocated the same parts of the header record for
-other purposes. As a result, @GNUTAR{} format is
-incompatible with the current @acronym{POSIX} specification, and with
-@command{tar} programs that follow it.
+@noindent
+where @samp{$TMPDIR} represents the value of the @var{TMPDIR}
+environment variable. If @var{TMPDIR} is not set, @command{tar}
+uses @samp{/tmp}.
-In the majority of cases, @command{tar} will be configured to create
-this format by default. This will change in the future releases, since
-we plan to make @samp{posix} format the default.
+@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,
+@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.
-To force creation a @GNUTAR{} archive, use option
-@option{--format=gnu}.
+@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}
+form except that it creates no global extended header records.
-@node posix
-@subsection @GNUTAR{} and @acronym{POSIX} @command{tar}
+When used with one of archive-reading commands, @command{tar} will
+behave as if these keyword/value pairs were included as records at the
+end of each extended header; thus, they will override any global or
+file-specific extended header record keywords of the same names.
+For example, in the command:
-@cindex POSIX archive format
-@cindex PAX archive format
-The version @value{VERSION} of @GNUTAR{} is able
-to read and create archives conforming to @acronym{POSIX.1-2001} standard.
+@smallexample
+tar --format=posix --create \
+ --file archive --pax-option gname:=user .
+@end smallexample
-A @acronym{POSIX} conformant archive will be created if @command{tar}
-was given @option{--format=posix} option.
+the group name will be forced to a new value for all files
+stored in the archive.
+@end table
@node Checksumming
@subsection Checksumming Problems
implement your own filters, not necessarily dealing with
compression/decomression. For example, suppose you wish to implement
PGP encryption on top of compression, using @command{gpg} (@pxref{Top,
-gpg, gpg ---- encryption and signing tool, gpg}). The following
-script does that:
+gpg, gpg ---- encryption and signing tool, gpg, GNU Privacy Guard
+Manual}). The following script does that:
@smallexample
@group
already crowded with options and moreover, the approach just explained
gives you a great deal of control already.
-@opindex same-permissions, short description
-@opindex preserve-permissions, short description
+@xopindex{same-permissions, short description}
+@xopindex{preserve-permissions, short description}
@item -p
@itemx --same-permissions
@itemx --preserve-permissions
@end table
-@node Standard
-@section Basic Tar Format
-@UNREVISED
-
-While an archive may contain many files, the archive itself is a
-single ordinary file. Like any other file, an archive file can be
-written to a storage device such as a tape or disk, sent through a
-pipe or over a network, saved on the active file system, or even
-stored in another archive. An archive file is not easy to read or
-manipulate without using the @command{tar} utility or Tar mode in
-@acronym{GNU} Emacs.
-
-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
-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
-information which @command{tar} uses to detect file corruption, and
-information about file types.
-
-Archives are permitted to have more than one member with the same
-member name. One way this situation can occur is if more than one
-version of a file has been stored in the archive. For information
-about adding new versions of a file to an archive, see @ref{update}.
-@FIXME-xref{To learn more about having more than one archive member with the
-same name, see -backup node, when it's written.}
-
-In addition to entries describing archive members, an archive may
-contain entries which @command{tar} itself uses to store information.
-@xref{label}, for an example of such an archive entry.
-
-A @command{tar} archive file contains a series of blocks. Each block
-contains @code{BLOCKSIZE} bytes. Although this format may be thought
-of as being on magnetic tape, other media are often used.
-
-Each file archived is represented by a header block which describes
-the file, followed by zero or more blocks which give the contents
-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
-particular @GNUTAR{} always issues a warning if it does not encounter it.
-
-The blocks may be @dfn{blocked} for physical I/O operations.
-Each record of @var{n} blocks (where @var{n} is set by the
-@option{--blocking-factor=@var{512-size}} (@option{-b @var{512-size}}) option to @command{tar}) is written with a single
-@w{@samp{write ()}} operation. On magnetic tapes, the result of
-such a write is a single record. When writing an archive,
-the last record of blocks should be written at the full size, with
-blocks after the zero block containing all zeros. When reading
-an archive, a reasonable system should properly handle an archive
-whose last record is shorter than the rest, or which contains garbage
-records after a zero block.
-
-The header block is defined in C as follows. In the @GNUTAR{}
-distribution, this is part of file @file{src/tar.h}:
-
-@smallexample
-@include header.texi
-@end smallexample
-
-All characters in header blocks are represented by using 8-bit
-characters in the local variant of ASCII. Each field within the
-structure is contiguous; that is, there is no padding used within
-the structure. Each character on the archive medium is stored
-contiguously.
-
-Bytes representing the contents of files (after the header block
-of each file) are not translated in any way and are not constrained
-to represent characters in any character set. The @command{tar} format
-does not distinguish text files from binary files, and no translation
-of file contents is performed.
-
-The @code{name}, @code{linkname}, @code{magic}, @code{uname}, and
-@code{gname} are null-terminated character strings. All other fields
-are zero-filled octal numbers in ASCII. Each numeric field of width
-@var{w} contains @var{w} minus 1 digits, and a null.
-
-The @code{name} field is the file name of the file, with directory names
-(if any) preceding the file name, separated by slashes.
-
-@FIXME{how big a name before field overflows?}
-
-The @code{mode} field provides nine bits specifying file permissions
-and three bits to specify the Set UID, Set GID, and Save Text
-(@dfn{sticky}) modes. Values for these bits are defined above.
-When special permissions are required to create a file with a given
-mode, and the user restoring files from the archive does not hold such
-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
-group permission could be copied from the @emph{other} permission.
-
-The @code{uid} and @code{gid} fields are the numeric user and group
-ID of the file owners, respectively. If the operating system does
-not support numeric user or group IDs, these fields should be ignored.
-
-The @code{size} field is the size of the file in bytes; linked files
-are archived with this field specified as zero. @FIXME-xref{Modifiers, in
-particular the @option{--incremental} (@option{-G}) option.}
-
-The @code{mtime} field is the data modification time of the file at
-the time it was archived. It is the ASCII representation of the octal
-value of the last time the file's contents were modified, represented
-as an integer number of
-seconds since January 1, 1970, 00:00 Coordinated Universal Time.
-
-The @code{chksum} field is the ASCII representation of the octal value
-of the simple sum of all bytes in the header block. Each 8-bit
-byte in the header is added to an unsigned integer, initialized to
-zero, the precision of which shall be no less than seventeen bits.
-When calculating the checksum, the @code{chksum} field is treated as
-if it were all blanks.
-
-The @code{typeflag} field specifies the type of file archived. If a
-particular implementation does not recognize or permit the specified
-type, the file will be extracted as if it were a regular file. As this
-action occurs, @command{tar} issues a warning to the standard error.
-
-The @code{atime} and @code{ctime} fields are used in making incremental
-backups; they store, respectively, the particular file's access and
-status change times.
-
-The @code{offset} is used by the @option{--multi-volume} (@option{-M}) option, when
-making a multi-volume archive. The offset is number of bytes into
-the file that we need to restart at to continue the file on the next
-tape, i.e., where we store the location that a continued file is
-continued at.
-
-The following fields were added to deal with sparse files. A file
-is @dfn{sparse} if it takes in unallocated blocks which end up being
-represented as zeros, i.e., no useful data. A test to see if a file
-is sparse is to look at the number blocks allocated for it versus the
-number of characters in the file; if there are fewer blocks allocated
-for the file than would normally be allocated for a file of that
-size, then the file is sparse. This is the method @command{tar} uses to
-detect a sparse file, and once such a file is detected, it is treated
-differently from non-sparse files.
-
-Sparse files are often @code{dbm} files, or other database-type files
-which have data at some points and emptiness in the greater part of
-the file. Such files can appear to be very large when an @samp{ls
--l} is done on them, when in truth, there may be a very small amount
-of important data contained in the file. It is thus undesirable
-to have @command{tar} think that it must back up this entire file, as
-great quantities of room are wasted on empty blocks, which can lead
-to running out of room on a tape far earlier than is necessary.
-Thus, sparse files are dealt with so that these empty blocks are
-not written to the tape. Instead, what is written to the tape is a
-description, of sorts, of the sparse file: where the holes are, how
-big the holes are, and how much data is found at the end of the hole.
-This way, the file takes up potentially far less room on the tape,
-and when the file is extracted later on, it will look exactly the way
-it looked beforehand. The following is a description of the fields
-used to handle a sparse file:
-
-The @code{sp} is an array of @code{struct sparse}. Each @code{struct
-sparse} contains two 12-character strings which represent an offset
-into the file and a number of bytes to be written at that offset.
-The offset is absolute, and not relative to the offset in preceding
-array element.
-
-The header can hold four of these @code{struct sparse} at the moment;
-if more are needed, they are not stored in the header.
-
-The @code{isextended} flag is set when an @code{extended_header}
-is needed to deal with a file. Note that this means that this flag
-can only be set when dealing with a sparse file, and it is only set
-in the event that the description of the file will not fit in the
-allotted room for sparse structures in the header. In other words,
-an extended_header is needed.
-
-The @code{extended_header} structure is used for sparse files which
-need more sparse structures than can fit in the header. The header can
-fit 4 such structures; if more are needed, the flag @code{isextended}
-gets set and the next block is an @code{extended_header}.
-
-Each @code{extended_header} structure contains an array of 21
-sparse structures, along with a similar @code{isextended} flag
-that the header had. There can be an indeterminate number of such
-@code{extended_header}s to describe a sparse file.
-
-@table @asis
-
-@item @code{REGTYPE}
-@itemx @code{AREGTYPE}
-These flags represent a regular file. In order to be compatible
-with older versions of @command{tar}, a @code{typeflag} value of
-@code{AREGTYPE} should be silently recognized as a regular file.
-New archives should be created using @code{REGTYPE}. Also, for
-backward compatibility, @command{tar} treats a regular file whose name
-ends with a slash as a directory.
-
-@item @code{LNKTYPE}
-This flag represents a file linked to another file, of any type,
-previously archived. Such files are identified in Unix by each
-file having the same device and inode number. The linked-to name is
-specified in the @code{linkname} field with a trailing null.
-
-@item @code{SYMTYPE}
-This represents a symbolic link to another file. The linked-to name
-is specified in the @code{linkname} field with a trailing null.
-
-@item @code{CHRTYPE}
-@itemx @code{BLKTYPE}
-These represent character special files and block special files
-respectively. In this case the @code{devmajor} and @code{devminor}
-fields will contain the major and minor device numbers respectively.
-Operating systems may map the device specifications to their own
-local specification, or may ignore the entry.
-
-@item @code{DIRTYPE}
-This flag specifies a directory or sub-directory. The directory
-name in the @code{name} field should end with a slash. On systems where
-disk allocation is performed on a directory basis, the @code{size} field
-will contain the maximum number of bytes (which may be rounded to
-the nearest disk block allocation unit) which the directory may
-hold. A @code{size} field of zero indicates no such limiting. Systems
-which do not support limiting in this manner should ignore the
-@code{size} field.
-
-@item @code{FIFOTYPE}
-This specifies a FIFO special file. Note that the archiving of a
-FIFO file archives the existence of this file and not its contents.
-
-@item @code{CONTTYPE}
-This specifies a contiguous file, which is the same as a normal
-file except that, in operating systems which support it, all its
-space is allocated contiguously on the disk. Operating systems
-which do not allow contiguous allocation should silently treat this
-type as a normal file.
-
-@item @code{A} @dots{} @code{Z}
-These are reserved for custom implementations. Some of these are
-used in the @acronym{GNU} modified format, as described below.
-
-@end table
-
-Other values are reserved for specification in future revisions of
-the P1003 standard, and should not be used by any @command{tar} program.
-
-The @code{magic} field indicates that this archive was output in
-the P1003 archive format. If this field contains @code{TMAGIC},
-the @code{uname} and @code{gname} fields will contain the ASCII
-representation of the owner and group of the file respectively.
-If found, the user and group IDs are used rather than the values in
-the @code{uid} and @code{gid} fields.
-
-For references, see ISO/IEC 9945-1:1990 or IEEE Std 1003.1-1990, pages
-169-173 (section 10.1) for @cite{Archive/Interchange File Format}; and
-IEEE Std 1003.2-1992, pages 380-388 (section 4.48) and pages 936-940
-(section E.4.48) for @cite{pax - Portable archive interchange}.
-
-@node Extensions
-@section @acronym{GNU} Extensions to the Archive Format
-@UNREVISED
-
-The @acronym{GNU} format uses additional file types to describe new types of
-files in an archive. These are listed below.
-
-@table @code
-@item GNUTYPE_DUMPDIR
-@itemx 'D'
-This represents a directory and a list of files created by the
-@option{--incremental} (@option{-G}) option. The @code{size} field gives the total
-size of the associated list of files. Each file name is preceded by
-either a @samp{Y} (the file should be in this archive) or an @samp{N}.
-(The file is a directory, or is not stored in the archive.) Each file
-name is terminated by a null. There is an additional null after the
-last file name.
-
-@item GNUTYPE_MULTIVOL
-@itemx 'M'
-This represents a file continued from another volume of a multi-volume
-archive created with the @option{--multi-volume} (@option{-M}) option. The original
-type of the file is not given here. The @code{size} field gives the
-maximum size of this piece of the file (assuming the volume does
-not end before the file is written out). The @code{offset} field
-gives the offset from the beginning of the file where this part of
-the file begins. Thus @code{size} plus @code{offset} should equal
-the original size of the file.
-
-@item GNUTYPE_SPARSE
-@itemx 'S'
-This flag indicates that we are dealing with a sparse file. Note
-that archiving a sparse file requires special operations to find
-holes in the file, which mark the positions of these holes, along
-with the number of bytes of data to be found after the hole.
-
-@item GNUTYPE_VOLHDR
-@itemx 'V'
-This file type is used to mark the volume header that was given with
-the @option{--label=@var{archive-label}} (@option{-V @var{archive-label}}) option when the archive was created. The @code{name}
-field contains the @code{name} given after the @option{--label=@var{archive-label}} (@option{-V @var{archive-label}}) option.
-The @code{size} field is zero. Only the first file in each volume
-of an archive should have this type.
-
-@end table
-
-You may have trouble reading a @acronym{GNU} format archive on a
-non-@acronym{GNU} system if the options @option{--incremental} (@option{-G}),
-@option{--multi-volume} (@option{-M}), @option{--sparse} (@option{-S}), or @option{--label=@var{archive-label}} (@option{-V @var{archive-label}}) were
-used when writing the archive. In general, if @command{tar} does not
-use the @acronym{GNU}-added fields of the header, other versions of
-@command{tar} should be able to read the archive. Otherwise, the
-@command{tar} program will give an error, the most likely one being a
-checksum error.
-
@node cpio
@section Comparison of @command{tar} and @command{cpio}
@UNREVISED
@file{<sys/mtio.h>}.
@table @option
-@opindex force-local, short description
+@xopindex{force-local, short description}
@item --force-local
Archive file is local even if it contains a colon.
@item -[0-7][lmh]
Specify drive and density.
-@opindex multi-volume, short description
+@xopindex{multi-volume, short description}
@item -M
@itemx --multi-volume
Create/list/extract multi-volume archive.
that may be larger than will fit on the medium used to hold it.
@xref{Multi-Volume Archives}.
-@opindex tape-length, short description
+@xopindex{tape-length, short description}
@item -L @var{num}
@itemx --tape-length=@var{num}
Change tape after writing @var{num} x 1024 bytes.
detect end of physical tapes. By being slightly conservative on the
maximum tape length, you might avoid the problem entirely.
-@opindex info-script, short description
-@opindex new-volume-script, short description
+@xopindex{info-script, short description}
+@xopindex{new-volume-script, short description}
@item -F @var{file}
@itemx --info-script=@var{file}
@itemx --new-volume-script=@var{file}
@opindex blocking-factor
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 (i.e. the size of a
record in units of 512 bytes) is called the @dfn{blocking factor}.
The @option{--blocking-factor=@var{512-size}} (@option{-b
@var{512-size}}) option specifies the blocking factor of an archive.
blocking factor (particularly if you're not sure what the blocking factor
is), you can usually use the @option{--read-full-records} (@option{-B}) option while
specifying a blocking factor larger then the blocking factor of the archive
-(ie. @samp{tar --extract --read-full-records --blocking-factor=300}.
+(i.e. @samp{tar --extract --read-full-records --blocking-factor=300}.
@xref{list}, for more information on the @option{--list} (@option{-t})
operation. @xref{Reading}, for a more detailed explanation of that option.
@command{tar} should rather drain the pipe out before exiting itself.
@end itemize
-@opindex ignore-zeros, short description
+@xopindex{ignore-zeros, short description}
@item -i
@itemx --ignore-zeros
Ignore blocks of zeros in archive (means EOF).
archive file, which may sometimes avoid problems when multiple files
are stored on a single physical tape.
-@opindex read-full-records, short description
+@xopindex{read-full-records, short description}
@item -B
@itemx --read-full-records
Reblock as we read (for reading 4.2BSD pipes).
@FIXME{Is there a better way to frob the spacing on the list?}
If you don't specify a @var{tapename}, @command{mt} uses the environment
-variable @env{TAPE}; if @env{TAPE} is not set, @command{mt} uses the device
-@file{/dev/rmt12}.
+variable @env{TAPE}; if @env{TAPE} is not set, @command{mt} will use
+the default device specified in your @file{sys/mtio.h} file
+(@code{DEFTAPE} variable). If this is not defined, the program will
+display a descriptive error message and exit with code 1.
@command{mt} returns a 0 exit status when the operation(s) were
successful, 1 if the command was unrecognized, and 2 if an operation
@node Using Multiple Tapes
@section Using Multiple Tapes
-@UNREVISED
Often you might want to write a large archive, one larger than will fit
on the actual tape you are using. In such a case, you can run multiple
@command{tar} commands, but this can be inconvenient, particularly if you
are using options like @option{--exclude=@var{pattern}} or dumping entire file systems.
-Therefore, @command{tar} supports multiple tapes automatically.
+Therefore, @command{tar} provides a special mode for creating
+multi-volume archives.
+
+@dfn{Multi-volume} archive is a single @command{tar} archive, stored
+on several media volumes of fixed size. Although in this section we will
+often call @samp{volume} a @dfn{tape}, there is absolutely no
+requirement for multi-volume archives to be stored on tapes. Instead,
+they can use whatever media type the user finds convenient, they can
+even be located on files.
+
+When creating a multi-volume arvhive, @GNUTAR{} continues to fill
+current volume until it runs out of space, then it switches to
+next volume (usually the operator is queried to replace the tape on
+this point), and continues working on the new volume. This operation
+continues untill all requested files are dumped. If @GNUTAR{} detects
+end of media while dumping a file, such a file is archived in split
+form. Some very big files can even be split across several volumes.
+
+Each volume is itself a valid @GNUTAR{} archive, so it can be read
+without any special options. Consequently any file member residing
+entirely on one volume can be extracted or otherwise operated upon
+without needing the other volume. Sure enough, to extract a split
+member you would need all volumes its parts reside on.
+
+Multi-volume archives suffer from several limitations. In particular,
+they cannot be compressed.
+
+@GNUTAR{} is able to create multi-volume archives of two formats
+(@pxref{Formats}): @samp{GNU} and @samp{POSIX}.
+
+@menu
+* Multi-Volume Archives:: Archives Longer than One Tape or Disk
+* Tape Files:: Tape Files
+* Tarcat:: Concatenate Volumes into a Single Archive
+
+@end menu
+
+@node Multi-Volume Archives
+@subsection Archives Longer than One Tape or Disk
+@cindex Multi-volume archives
+
+@opindex multi-volume
+To create an archive that is larger than will fit on a single unit of
+the media, use the @option{--multi-volume} (@option{-M}) option in conjunction with
+the @option{--create} option (@pxref{create}). A @dfn{multi-volume}
+archive can be manipulated like any other archive (provided the
+@option{--multi-volume} option is specified), but is stored on more
+than one tape or disk.
+
+When you specify @option{--multi-volume}, @command{tar} does not report an
+error when it comes to the end of an archive volume (when reading), or
+the end of the media (when writing). Instead, it prompts you to load
+a new storage volume. If the archive is on a magnetic tape, you
+should change tapes when you see the prompt; if the archive is on a
+floppy disk, you should change disks; etc.
+
+@table @option
+@item --multi-volume
+@itemx -M
+Creates a multi-volume archive, when used in conjunction with
+@option{--create} (@option{-c}). To perform any other operation on a multi-volume
+archive, specify @option{--multi-volume} in conjunction with that
+operation.
+For example:
+
+@smallexample
+$ @kbd{tar --create --multi-volume --file=/dev/tape @var{files}}
+@end smallexample
+@end table
+
+The method @command{tar} uses to detect end of tape is not perfect, and
+fails on some operating systems or on some devices. If @command{tar}
+cannot detect the end of the tape itself, you can use
+@option{--tape-length} option to inform it about the capacity of the
+tape:
+
+@anchor{tape-length}
+@table @option
+@opindex tape-length
+@item --tape-length=@var{size}
+@itemx -L @var{size}
+Set maximum length of a volume. The @var{size} argument should then
+be the usable size of the tape in units of 1024 bytes. This option
+selects @option{--multi-volume} automatically. For example:
+
+@smallexample
+$ @kbd{tar --create --tape-length=41943040 --file=/dev/tape @var{files}}
+@end smallexample
+@end table
+
+@anchor{change volume prompt}
+When @GNUTAR{} comes to the end of a storage media, it asks you to
+change the volume. The built-in prompt for POSIX locale
+is@footnote{If you run @GNUTAR{} under a different locale, the
+translation to the locale's language will be used.}:
-Use @option{--multi-volume} (@option{-M}) on the command line, and
-then @command{tar} will, when it reaches the end of the tape, prompt
-for another tape, and continue the archive. Each tape will have an
-independent archive, and can be read without needing the other. (As
-an exception to this, the file that @command{tar} was archiving when
-it ran out of tape will usually be split between the two archives; in
-this case you need to extract from the first archive, using
-@option{--multi-volume}, and then put in the second tape when
-prompted, so @command{tar} can restore both halves of the file.)
+@smallexample
+Prepare volume #@var{n} for `@var{archive}' and hit return:
+@end smallexample
-@GNUTAR{} multi-volume archives do not use a truly portable format.
-You need @GNUTAR{} at both ends to process them properly.
+@noindent
+where @var{n} is the ordinal number of the volume to be created and
+@var{archive} is archive file or device name.
When prompting for a new tape, @command{tar} accepts any of the following
responses:
Request @command{tar} to write the next volume on the file @var{file-name}.
@item !
Request @command{tar} to run a subshell. This option can be disabled
-by giving @option{--restrict} command line option to @command{tar}.
+by giving @option{--restrict} command line option to
+@command{tar}@footnote{@xref{--restrict}, for more information about
+this option}.
@item y
Request @command{tar} to begin writing the next volume.
@end table
(You should only type @samp{y} after you have changed the tape;
otherwise @command{tar} will write over the volume it just finished.)
+@cindex Volume number file
+@cindex volno file
+@anchor{volno-file}
+@opindex volno-file
+The volume number used by @command{tar} in its tape-changing prompt
+can be changed; if you give the
+@option{--volno-file=@var{file-of-number}} option, then
+@var{file-of-number} should be an unexisting file to be created, or
+else, a file already containing a decimal number. That number will be
+used as the volume number of the first volume written. When
+@command{tar} is finished, it will rewrite the file with the
+now-current volume number. (This does not change the volume number
+written on a tape label, as per @ref{label}, it @emph{only} affects
+the number used in the prompt.)
+
@cindex End-of-archive info script
@cindex Info script
@anchor{info-script}
@opindex info-script
@opindex new-volume-script
-If you want more elaborate behavior than this, give @command{tar} the
-@option{--info-script=@var{script-name}}
-(@option{--new-volume-script=@var{script-name}}, @option{-F
-@var{script-name}}) option. The file @var{script-name} is expected to
-be a program (or shell script) to be run instead of the normal
-prompting procedure. It is executed without any command line
-arguments. Additional data is passed to it via the following
+If you want more elaborate behavior than this, you can write a special
+@dfn{new volume script}, that will be responsible for changing the
+volume, and instruct @command{tar} to use it instead of its normal
+prompting procedure:
+
+@table @option
+@item --info-script=@var{script-name}
+@itemx --new-volume-script=@var{script-name}
+@itemx -F @var{script-name}
+Specify the full name of the volume script to use. The script can be
+used to eject cassettes, or to broadcast messages such as
+@samp{Someone please come change my tape} when performing unattended
+backups.
+@end table
+
+The @var{script-name} is executed without any command line
+arguments. It inherits @command{tar}'s shell environment.
+Additional data is passed to it via the following
environment variables:
@table @env
@vrindex TAR_SUBCOMMAND, info script environment variable
@item TAR_SUBCOMMAND
-Short option describing the operation @command{tar} is executed.
+Short option describing the operation @command{tar} is executing
@xref{Operations}, for a complete list of subcommand options.
@vrindex TAR_FORMAT, info script environment variable
list of archive format names.
@end table
-The info script can instruct @command{tar} to use new archive name,
-by writing in to file descriptor 3 (see below for an
-example).
+The volume script can instruct @command{tar} to use new archive name,
+by writing in to file descriptor 3 (see below for an example).
If the info script fails, @command{tar} exits; otherwise, it begins
writing the next volume.
-The method @command{tar} uses to detect end of tape is not perfect, and
-fails on some operating systems or on some devices. You can use the
-@option{--tape-length=@var{size}} (@option{-L @var{size}}) option if
-@command{tar} can't detect the end of the tape itself. This option
-selects @option{--multi-volume} (@option{-M}) automatically. The
-@var{size} argument should then be the usable size of the tape in
-units of 1024 bytes. But for many devices, and floppy disks in
-particular, this option is never required for real, as far as we know.
-
-@cindex Volume number file
-@cindex volno file
-@anchor{volno-file}
-@opindex volno-file
-The volume number used by @command{tar} in its tape-change prompt
-can be changed; if you give the
-@option{--volno-file=@var{file-of-number}} option, then
-@var{file-of-number} should be an unexisting file to be created, or
-else, a file already containing a decimal number. That number will be
-used as the volume number of the first volume written. When
-@command{tar} is finished, it will rewrite the file with the
-now-current volume number. (This does not change the volume number
-written on a tape label, as per @ref{label}, it @emph{only} affects
-the number used in the prompt.)
-
If you want @command{tar} to cycle through a series of files or tape
drives, there are three approaches to choose from. First of all, you
-can give @command{tar} multiple @option{--file} options. In this case
+can give @command{tar} multiple @option{--file} options. In this case
the specified files will be used, in sequence, as the successive
volumes of the archive. Only when the first one in the sequence needs
to be used again will @command{tar} prompt for a tape change (or run
-the info script). Secondly, you can use the @samp{n} response to the
-tape-change prompt, and, finally, you can use an info script, that
-writes new archive name to file descriptor. The following example
-illustrates this approach:
+the info script). For example, suppose someone has two tape drives on
+a system named @file{/dev/tape0} and @file{/dev/tape1}. For having
+@GNUTAR{} to switch to the second drive when it needs to write the
+second tape, and then back to the first tape, etc., just do either of:
+
+@smallexample
+$ @kbd{tar --create --multi-volume --file=/dev/tape0 --file=/dev/tape1 @var{files}}
+$ @kbd{tar cMff /dev/tape0 /dev/tape1 @var{files}}
+@end smallexample
+
+The second method is to use the @samp{n} response to the tape-change
+prompt.
+
+Finally, the most flexible approach is to use a volume script, that
+writes new archive name to the file descriptor #3. For example, the
+following volume script will create a series of archive files, named
+@file{@var{archive}-@var{vol}}, where @var{archive} is the name of the
+archive being created (as given by @option{--file} option) and
+@var{vol} is the ordinal number of the archive being created:
@smallexample
@group
@end group
@end smallexample
-Each volume of a multi-volume archive is an independent @command{tar}
-archive, complete in itself. For example, you can list or extract any
-volume alone; just don't specify @option{--multi-volume}
-(@option{-M}). However, if one file in the archive is split across
-volumes, the only way to extract it successfully is with a
-multi-volume extract command @option{--extract --multi-volume}
-(@option{-xM}) starting on or before the volume where the file begins.
-
-For example, let's presume someone has two tape drives on a system
-named @file{/dev/tape0} and @file{/dev/tape1}. For having @GNUTAR{}
-to switch to the second drive when it needs to write the
-second tape, and then back to the first tape, etc., just do either of:
+The same script cant be used while listing, comparing or extracting
+from the created archive. For example:
@smallexample
-$ @kbd{tar --create --multi-volume --file=/dev/tape0 --file=/dev/tape1 @var{files}}
-$ @kbd{tar cMff /dev/tape0 /dev/tape1 @var{files}}
+@group
+# @r{Create a multi-volume archive:}
+$ @kbd{tar -c -L1024 -f archive.tar -F new-volume .}
+# @r{Extract from the created archive:}
+$ @kbd{tar -x -f archive.tar -F new-volume .}
+@end group
@end smallexample
-@menu
-* Multi-Volume Archives:: Archives Longer than One Tape or Disk
-* Tape Files:: Tape Files
-* Tarcat:: Concatenate Volumes into a Single Archive
-
-@end menu
-
-@node Multi-Volume Archives
-@subsection Archives Longer than One Tape or Disk
-@cindex Multi-volume archives
-@UNREVISED
-
-@opindex multi-volume
-To create an archive that is larger than will fit on a single unit of
-the media, use the @option{--multi-volume} (@option{-M}) option in conjunction with
-the @option{--create} option (@pxref{create}). A @dfn{multi-volume}
-archive can be manipulated like any other archive (provided the
-@option{--multi-volume} option is specified), but is stored on more
-than one tape or disk.
-
-When you specify @option{--multi-volume}, @command{tar} does not report an
-error when it comes to the end of an archive volume (when reading), or
-the end of the media (when writing). Instead, it prompts you to load
-a new storage volume. If the archive is on a magnetic tape, you
-should change tapes when you see the prompt; if the archive is on a
-floppy disk, you should change disks; etc.
+@noindent
+Notice, that the first command had to use @option{-L} option, since
+otherwise @GNUTAR{} will end up writing everything to file
+@file{archive.tar}.
You can read each individual volume of a multi-volume archive as if it
were an archive by itself. For example, to list the contents of one
that volume), use @option{--extract}, again without
@option{--multi-volume}.
-If an archive member is split across volumes (ie. its entry begins on
+If an archive member is split across volumes (i.e. its entry begins on
one volume of the media and ends on another), you need to specify
@option{--multi-volume} to extract it successfully. In this case, you
should load the volume where the archive member starts, and use
volumes as it needs them. @xref{extracting archives}, for more
information about extracting archives.
-@option{--info-script=@var{script-name}}
-(@option{--new-volume-script=@var{script-name}}, @option{-F
-@var{script-name}}) (@pxref{info-script}) is like
-@option{--multi-volume} (@option{-M}), except that @command{tar} does
-not prompt you directly to change media volumes when a volume is
-full---instead, @command{tar} runs commands you have stored in
-@var{script-name}. For example, this option can be used to eject
-cassettes, or to broadcast messages such as @samp{Someone please come
-change my tape} when performing unattended backups. When
-@var{script-name} is done, @command{tar} will assume that the media
-has been changed.
-
Multi-volume archives can be modified like any other archive. To add
files to a multi-volume archive, you need to only mount the last
volume of the archive media (and new volumes, if needed). For all
other operations, you need to use the entire archive.
If a multi-volume archive was labeled using
-@option{--label=@var{archive-label}} (@option{-V @var{archive-label}})
-(@pxref{label}) when it was created, @command{tar} will not
-automatically label volumes which are added later. To label
-subsequent volumes, specify @option{--label=@var{archive-label}} again
-in conjunction with the @option{--append}, @option{--update} or
-@option{--concatenate} operation.
-
-@cindex Labeling multi-volume archives
-@FIXME{example}
-
-@FIXME{There should be a sample program here, including an exit
-before end. Is the exit status even checked in tar? :-(}
-
-@table @option
-@item --multi-volume
-@itemx -M
-Creates a multi-volume archive, when used in conjunction with
-@option{--create} (@option{-c}). To perform any other operation on a multi-volume
-archive, specify @option{--multi-volume} in conjunction with that
-operation.
-
-@item --info-script=@var{program-file}
-@itemx --new-volume-script=@var{program-file}
-@itemx -F @var{program-file}
-Creates a multi-volume archive via a script. Used in conjunction with
-@option{--create} (@option{-c}). @xref{info-script}, dor a detailed discussion.
-@end table
-
+@option{--label=@var{archive-label}} (@pxref{label}) when it was
+created, @command{tar} will not automatically label volumes which are
+added later. To label subsequent volumes, specify
+@option{--label=@var{archive-label}} again in conjunction with the
+@option{--append}, @option{--update} or @option{--concatenate} operation.
+
+@FIXME{This is no longer true: Multivolume archives in @samp{POSIX}
+format can be extracted using any posix-compliant tar
+implementation. The split members can then be recreated from parts
+using a simple shell script. Provide more information about it:}
Beware that there is @emph{no} real standard about the proper way, for
a @command{tar} archive, to span volume boundaries. If you have a
multi-volume created by some vendor's @command{tar}, there is almost
@section Including a Label in the Archive
@cindex Labeling an archive
@cindex Labels on the archive media
+@cindex Labeling multi-volume archives
@UNREVISED
@opindex label
operation, or can compare a previously written archive, to insure that
it is up to date.
-@opindex verify, using with @option{--create}
-@opindex create, using with @option{--verify}
+@xopindex{verify, using with @option{--create}}
+@xopindex{create, using with @option{--verify}}
To check for discrepancies in an archive immediately after it is
written, use the @option{--verify} (@option{-W}) option in conjunction with
the @option{--create} operation. When this option is
If you want to tar to mimic the behavior of versions prior to 1.15.91,
add this option to your @env{TAR_OPTIONS} variable.
-@xref{Wildcards}, for the detailed discussion of the use of globbing
+@xref{wildcards}, for the detailed discussion of the use of globbing
patterns by @GNUTAR{}.
@item Use of short option @option{-o}.
distribution tarballs. @xref{Formats,v7}, for the detailed discussion
of this issue and its implications.
-@FIXME{Change the first argument to tar-formats if and when Automake
-people accept my patch to the documentation, and the new Automake is
-out --Sergey 2006-05-25}.
+@FIXME{Change the first argument to tar-formats when the new Automake is
+out. The proposition to add @anchor{} to the appropriate place of its
+docs was accepted by Automake people --Sergey 2006-05-25}.
@xref{Options, tar-v7, Changing Automake's Behavior,
automake, GNU Automake}, for a description on how to use various
archive formats with @command{automake}.
@appendix Genfile
@include genfile.texi
-@node Snapshot Files
-@appendix Format of the Incremental Snapshot Files
-@include snapshot.texi
+@node Tar Internals
+@appendix Tar Internals
+@include intern.texi
@node Free Software Needs Free Documentation
@appendix Free Software Needs Free Documentation
This appendix contains an index of all @GNUTAR{} long command line
options. The options are listed without the preceeding double-dash.
-
-@FIXME{@itemize
-@item Make sure @emph{all} options are indexed.
-@item Provide an index of short options
-@end itemize}
+For a cross-reference of short command line options, @ref{Short Option Summary}.
@printindex op
projects / chaz / tar / blobdiff