1 GNU tar NEWS - User visible changes. 2013-01-26
2 Please send GNU tar bug reports to <bug-tar@gnu.org>
9 ** Sparse files with large data
11 When creating a PAX-format archive, tar no longer arbitrarily restricts
12 the size of the representation of a sparse file to be less than 8 GiB.
16 In the default C locale, diagnostics and output of 'tar' have been
17 adjusted to quote 'like this' (with apostrophes) instead of `like this'
18 (with an accent grave character and an apostrophe). This tracks
19 recent changes to the GNU coding standards.
21 * --owner and --group names and numbers
23 The --owner and --group options now accept operands of the form
24 NAME:NUM, so that you can specify both symbolic name and numeric ID
25 for owner and group. In these options, NAME no longer needs to be
26 present in the current host's user and group databases.
28 * The --keep-old-files and --skip-old-files options.
30 This release restores the traditional functionality of the
31 --keep-old-files. This option causes tar to avoid replacing
32 existing files while extracting and to treat such files as errors.
33 Tar will emit a prominent error message upon encountering such files
34 and will exit with code 2 when finished extracting the archive.
36 A new option --skip-old-files is introduced, which acts exactly as
37 --keep-old-files, except that it does not treat existing files as
38 errors. Instead it just silently skips them. An additional level of
39 verbosity can be obtained by using the option --warning=existing-file
40 together with this option.
42 * Support for POSIX ACLs, extended attributes and SELinux context.
44 Starting with this version tar is able to store, extract and list
45 extended file attributes, POSIX.1e ACLs and SELinux context. This is
46 controlled by the command line options --xattrs, --acls and --selinux,
47 correspondingly. Each of these options has a `--no-' counterpart
48 (e.g. --no-xattrs), which disables the corresponding feature.
49 Additionally, the options --xattrs-include and --xattrs-exclude allow
50 you to selectively control for which files to store (or extract) the
53 * New configure option --enable-gcc-warnings, intended for debugging.
56 version 1.26 - Sergey Poznyakoff, 2011-03-12
60 ** Fix the --verify option, which broke in version 1.24.
62 ** Fix storing long sparse file names in PAX archives.
64 ** Fix correctness of --atime-preserve=replace
66 tar --atime-preserve=replace no longer tries to restore atime of
69 ** Work around POSIX incompatibilities on FreeBSD, NetBSD and Tru64
71 ** Fix bug with --one-file-system --listed-incremental
73 When invoked with these two options, tar 1.25 would add only the
74 top-level directory to the archive, but not its contents.
77 version 1.25 - Sergey Poznyakoff, 2010-11-07
79 * Fix extraction of empty directories with the -C option in effect.
80 * Fix extraction of device nodes.
81 * Make sure name matching occurs before eventual name transformation.
83 Tar 1.24 changed the ordering of name matching and name transformation
84 so that the former saw already transformed file names. This made it
85 impossible to match file names in certain cases. It is fixed now.
87 * Fix the behavior of tar -x --overwrite on hosts lacking O_NOFOLLOW.
89 * Improve the testsuite.
91 * Alternative decompression programs.
93 If extraction from a compressed archive fails because the corresponding
94 compression program is not installed and the following two conditions
95 are met, tar retries extraction using an alternative decompressor:
97 1. Another compression program supported by tar is able to handle this
99 2. The compression program was not explicitly requested in the command
100 line by the use of such options as -z, -j, etc.
102 For example, if 'compress' is not available, tar will try 'gzip'.
105 version 1.24 - Sergey Poznyakoff, 2010-10-24
107 * The --full-time option.
109 New command line option '--full-time' instructs tar to output file
110 time stamps to the full resolution.
114 ** More reliable directory traversal when creating archives
116 Tar now checks for inconsistencies caused when a file system is
117 modified while tar is creating an archive. In the new approach, tar
118 maintains a cache of file descriptors to directories, so it uses more
119 file descriptors than before, but it adjusts to system limits on
120 the number of file descriptors. Tar also takes more care when
121 a file system is modified while tar is extracting from an archive.
123 The new checks are implemented via the openat and related calls
124 standardized by POSIX.1-2008. On an older system where these calls do
125 not exist or do not return useful results, tar emulates the calls at
126 some cost in efficiency and reliability.
128 ** Symbolic link attributes
130 When extracting symbolic links, tar now restores attributes such as
131 last-modified time and link permissions, if the operating system
132 supports this. For example, recent versions of the Linux kernel
133 support setting times on symlinks, and some BSD kernels also support
136 ** --dereference consistency
138 The --dereference (-h) option now applies to files that are copied
139 into or out of archives, independently of other options. For example,
140 if F is a symbolic link and archive.tar contains a regular-file member
141 also named F, "tar --overwrite -x -f archive.tar F" now overwrites F
142 itself, rather than the file that F points to. (To overwrite the file
143 that F points to, add the --dereference (-h) option.) Formerly,
144 --dereference was intended to apply only when using the -c option, but
145 the implementation was not consistent.
147 Also, the --dereference option no longer affects accesses to other
148 files, such as archives and time stamp files. Symbolic links to these
149 files are always followed. Previously, the links were usually but not
152 ** Spurious error diagnostics on broken pipe.
154 When receiving SIGPIPE, tar would exit with error status and
155 "write error" diagnostics. In particular, this occurred if
156 invoked as in the example below:
158 tar tf archive.tar | head -n 1
162 'tar --remove-files' failed to remove a directory which contained
163 symlinks to another files within that directory.
165 ** --test-label behavior
167 In case of a mismatch, 'tar --test-label LABEL' exits with code 1,
168 not 2 as it did in previous versions.
170 The '--verbose' option used with '--test-label' provides additional
173 Several volume labels may be specified in a command line, e.g.:
175 tar --test-label -f archive 'My volume' 'New volume' 'Test volume'
177 In this case, tar exits with code 0 if any one of the arguments
178 matches the actual volume label.
180 ** --label used with --update
182 The '--label' option can be used with '--update' to prevent accidental
183 update of an archive:
185 tar -rf archive --label 'My volume' .
187 This did not work in previous versions, in spite of what the docs said.
189 ** --record-size and --tape-length (-L) options
191 Usual size suffixes are allowed for these options. For example,
192 -L10k stands for a 10 kilobyte tape length.
194 ** Fix dead loop on extracting existing symlinks with the -k option.
197 version 1.23 - Sergey Poznyakoff, 2010-03-10
199 * Record size autodetection
201 When listing or extracting archives, the actual record size is
202 reported only if the archive is read from a device (as opposed
203 to regular files and pipes).
207 When a read-only operation (e.g. --list or --extract) is requested
208 on a regular file, tar attemtps to speed up accesses by using lseek.
210 * New command line option '--warning'
212 The '--warning' command line option allows to suppress or enable
213 particular warning messages during 'tar' run. It takes a single
214 argument (a 'keyword'), identifying the class of warning messages
215 to affect. If the argument is prefixed with 'no-', such warning
216 messages are suppressed. For example,
218 tar --warning=no-alone-zero-block -x -f archive
220 suppresses the output of "A lone zero block" diagnostics, which is
221 normally issued if 'archive' ends with a single block of zeros.
223 See Tar Manual, section 3.9 "Controlling Warning Messages", for a
226 * New command line option '--level'
228 The '--level=N' option sets the incremental dump level N. It
229 is valid when used in conjunction with the -c and --listed-incremental
230 options. So far the only meaningful value for N is 0. The
231 '--level=0' option forces creating the level 0 dump, by truncating
232 the snapshot file if it exists.
234 * Files removed during incremental dumps
236 If a file or directory is removed while incremental dump is
237 in progress, tar exact actions depend on whether this file
238 was explicitly listed in the command line, or was found
239 during file system scan.
241 If the file was explicitly listed in the command line, tar
242 issues error message and exits with the code 2, meaning
245 Otherwise, if the file was found during the file system scan,
246 tar issues a warning, saying "File removed before we read it",
247 and sets exit code to 1, which means "some files differ".
248 If the --warning=no-file-removed option is given, no warning
249 is issued and exit code remains 0.
251 * Modification times of PAX extended headers.
253 Modification times in ustar header blocks of extended headers
254 are set to mtimes of the corresponding archive members. This
255 can be overridden by the
257 --pax-opion='exthdr.mtime=STRING'
259 command line option. The STRING is either number of seconds since
260 the Epoch or a "Time reference" (see below).
262 Modification times in ustar header blocks of global extended
263 headers are set to the time when tar was invoked.
265 This can be overridden by the
267 --pax-opion='globexthdr.mtime=STRING'
269 command line option. The STRING is either number of seconds since
270 the Epoch or a "Time reference" (see below).
272 * Time references in --pax-option argument.
274 Any value from the --pax-option argument that is enclosed in a pair
275 of curly braces represents a time reference. The string between the
276 braces is understood either as a textual time representation, as described in
277 chapter 7, "Date input formats", of the Tar manual, or as a name of
278 an existing file, starting with '/' or '.'. In the latter
279 case, it is replaced with the modification time of that file.
281 * Environment of --to-command script.
283 The environment passed to the --to-command script is extended with
284 the following variables:
286 TAR_VERSION GNU tar version number
287 TAR_ARCHIVE The name of the archive
288 TAR_VOLUME Ordinal number of the volume
289 TAR_FORMAT Format of the archive
290 TAR_BLOCKING_FACTOR Current blocking factor
293 ** Fix handling of hard link targets by -c --transform.
294 ** Fix hard links recognition with -c --remove-files.
295 ** Fix restoring files from backup (debian bug #508199).
296 ** Correctly restore modes and permissions on existing directories.
297 ** The --remove-files option removes files only if they were
298 succesfully stored in the archive.
299 ** Fix storing and listing of the volume labels in POSIX format.
300 ** Improve algorithm for splitting long file names (ustar
302 ** Fix possible memory overflow in the rmt client code (CVE-2010-0624).
305 version 1.22 - Sergey Poznyakoff, 2009-03-05
307 * Support for xz compression
309 Tar uses xz for compression if one of the following conditions is met:
311 1. The option --xz or -J (see below) is used.
312 2. The xz binary is set as compressor using --use-compress-program option.
313 3. The file name of the archive being created ends in '.xz' and
314 auto-compress option (-a) is used.
316 Xz is used for decompression if one of the following conditions is met:
318 1. The option --xz or -J is used.
319 2. The xz binary is set as compressor using --use-compress-program option.
320 3. The file is recognized as xz compressed stream data.
322 * Short option -J reassigned as a short equivalent of --xz
326 The -I option is assigned as a short equivalent for
327 --use-compress-program.
329 * The --no-recursive option works in incremental mode.
332 version 1.21 - Sergey Poznyakoff, 2008-12-27
334 * New short option -J
336 A shortcut for --lzma.
340 * New option --no-auto-compress
342 Cancels the effect of previous --auto-compress (-a) option.
344 * New option --no-null
346 Cancels the effect of previous --null option.
348 * Compressed format recognition
350 If tar is unable to determine archive compression format, it falls
351 back to using archive suffix to determine it.
355 Using --exclude-vcs handles also files used internally by Bazaar,
358 * Transformation scope flags
360 Name transformation expressions understand additional flags that
361 control type of archive members affected by them. The flags are:
364 Apply transformation to regular archive members.
367 Apply transformation to symbolic link targets.
370 Apply transformation to hard link targets.
372 Corresponding upper-case letters negate the meaning, so that
373 'H' means "do not apply transformation to hard link targets".
375 The scope flags are listed in the third part of an 's' expression,
378 tar --transform 's|^|/usr/local/|S'
380 Default is 'rsh', which means that transformations are applied to
381 both regular archive members and to the targets of symbolic and hard
382 links. If several transform expressions are used, the default flags
383 can be changed using 'flags=' statement before the expressions, e.g.:
385 tar --transform 'flags=S;s|^|/usr/local/|S'
389 ** The --null option disabled handling of tar options in list files. This
391 ** Fixed record size autodetection. If the detected record size differs from
392 the expected value (either default one, or the one set from the
393 command line), tar always prints a warning if verbosity level is set
394 to 1 or greater, i.e. if either -t or -v option is given.
398 version 1.20 - Sergey Poznyakoff, 2008-04-14
400 * New option --auto-compress (-a)
402 With --create, selects compression algorithm basing on the suffix
403 of the archive file name.
407 Selects LZMA compression algorithm
409 * New option --hard-dereference
411 During archive creation, dereferences hard links and stores the files
412 they refer to, instead of creating usual hard link members (type '1').
414 * New option --checkpoint-action
416 This action allows to specify an action to be executed upon hitting a
417 checkpoint. Recognized actions are: dot, echo (the default),
418 echo=string, ttyout=string, exec=cmdline, and sleep=value. Any number
419 of '--checkpoint-action' options can be specified, the actions will be
420 executed in order of their appearance in the command line. See
421 chapter 3.8 "Checkpoints" for a complete description.
423 * New options --no-check-device, --check-device.
425 The '--no-check-device' option disables comparing device numbers during
426 preparatory stage of an incremental dump. This allows to avoid
427 creating full dumps if the device numbers change (e.g. when using an
430 The '--check-device' option enables comparing device numbers. This is
431 the default. This option is provided to undo the effect of the previous
432 '--no-check-device' option, e.g. if it was set in TAR_OPTIONS
433 environment variable.
435 * The --transform option.
437 Any number of '--transform' options can be given in the command line.
438 The specified transformations will be applied in turn.
440 The argument to '--transform' option can be a list of replace
441 expressions, separated by a semicolon (as in 'sed').
443 Filename transformations are applied to symbolic link targets
444 during both creation and extraction. Tar 1.19 used them only
447 For a detailed description, see chapter 6.7 "Modifying File and Member
450 * Info (end-of-volume) scripts
452 The value of the blocking factor is made available to info and
453 checkpoint scripts via environment variable TAR_BLOCKING_FACTOR.
455 * Incremental archives
457 Improved (sped up) extracting from incremental archives.
460 ** Fix bug introduced in version 1.19: tar refused to update non-existing
464 version 1.19 - Sergey Poznyakoff, 2007-10-10
466 * New option --exclude-vcs
468 Excludes directories and files, created by several widely used version
469 control systems, e.g. "CVS/", ".svn/", etc.
471 * --exclude-tag and --exclude-cache options
473 The following options now work with incremental archives as well:
481 * Fix handling of renamed files in listed incremental archives.
483 Previous versions always stored absolute file names in rename
484 records, even if -P was not used. This is fixed: rename records
485 contain file names processed in accordance with the command line
488 * Fix --version output.
490 * Recognition of broken archives.
492 When supplied an archive smaller than 512 bytes in reading mode (-x,
493 -t), the previous version of tar silently ignored it, exiting with
494 code 0. It is fixed. Tar now issues the following diagnostic message:
495 'This does not look like a tar archive', and exits with code 2.
497 * Fix double-dot recognition in archive member names in case of duplicate '/.'.
499 * Fix file padding in case of truncation of the input file to zero size.
502 version 1.18 - Sergey Poznyakoff, 2007-06-29
504 * Licensed under the GPLv3
506 * Fixed several bugs in the testsuite
509 version 1.17 - Sergey Poznyakoff, 2007-06-08
511 * Fix archivation of sparse files in posix mode. Previous versions padded
512 sparse members with spurious zero blocks.
514 * Fix operation of --verify --listed-incremental. Version 1.16.1 produced
515 a full dump when both options were given.
517 * Fix --occurrence. In previous versions it continued scanning the archive
518 even though all requested members has already been extracted.
520 * Scope of --transform and --strip-components options.
522 In addition to affecting regular archive members, the --transform
523 option affects hard and soft link targets and the --strip-components
524 option affects hard link targets as well.
526 * End-of-volume script can send the new volume name to tar by writing
527 it to the file descriptor stored in the environment variable TAR_FD.
530 version 1.16.1 - Sergey Poznyakoff, 2006-12-09
532 * New option --exclude-tag allows to specify "exclusion tag files", i.e.
533 files whose presence in a directory means that the directory should not
536 * The --exclude-cache option excludes directories that contain the
537 CACHEDIR.TAG file from being archived. Previous versions excluded
538 directory contents only, while the directories themselves were
539 still added to the archive.
541 * Support for reading ustar type 'N' header logical records has been removed.
542 This GNU extension was generated only by very old versions of GNU 'tar'.
543 Unfortunately its implementation had security holes; see
544 <http://archives.neohapsis.com/archives/fulldisclosure/2006-11/0344.html>.
545 We don't expect that any tar archives in practical use have type 'N'
546 records, but if you have one and you trust its contents, you can
547 decode it with GNU tar 1.16 or earlier.
549 * Race conditions have been fixed that in some cases briefly allowed
550 files extracted by 'tar -x --same-owner' (or plain 'tar -x', when
551 running as root) to be accessed by users that they shouldn't have been.
554 version 1.16 - Sergey Poznyakoff, 2006-10-21
556 * After creating an archive, tar exits with code 1 if some files were
557 changed while being read. Previous versions exited with code 2 (fatal
558 error), and only if some files were truncated while being archived.
560 * New option --mtime allows to set modification times for all archive
561 members during creation.
564 ** Avoid running off file descriptors when using multiple -C options.
565 ** tar --index-file=FILE --file=- sent the archive to FILE, and
566 the listing to stderr.
569 version 1.15.91 - Sergey Poznyakoff, 2006-06-16
571 * Incompatible changes
575 Previous versions of GNU tar assumed shell-style globbing when
576 extracting from or listing an archive. For example:
580 would extract all files whose names end in '.c'. This behavior
581 was not documented and was incompatible with traditional tar
582 implementations. Therefore, starting from this version, GNU tar
583 no longer uses globbing by default. For example, the above invocation
584 is now interpreted as a request to extract from the archive the file
587 To treat member names as globbing patterns, use --wildcards option.
588 If you wish tar to mimic the behavior of versions up to 1.15.90,
589 add --wildcards to the value of the environment variable TAR_OPTIONS.
591 The exact way in which tar interprets member names is controlled by the
592 following command line options:
594 --wildcards use wildcards
595 --anchored patterns match file name start
596 --ignore-case ignore case
597 --wildcards-match-slash wildcards match '/'
599 Each of these options has a '--no-' counterpart that disables its
600 effect (e.g. --no-wildcards).
602 These options affect both the interpretation of member names from
603 command line and that of the exclusion patterns (given with --exclude
604 and --exclude-from options). The defaults are:
606 1. For member names: --no-wildcards --anchored
607 2. For exclusion patterns: --wildcards --no-anchored --wildcards-match-slash
609 The options can appear multiple times in the command line, thereby
610 changing the way command line arguments are interpreted. For example,
611 to use case-insensitive matching in exclude patterns and to revert to
612 case-sensitive matching for the rest of command line, one could write:
614 tar xf foo.tar --ignore-case --exclude-from=FILE --no-ignore-case file.name
616 ** Short option -l is now an alias of --check-links option, which complies
617 with UNIX98. This ends the transition period started with version 1.14.
621 ** New option --transform allows to transform file names before storing them
622 in the archive or member names before extracting. The option takes a
623 sed replace expression as its argument. For example,
625 tar cf foo.tar --transform 's,^,prefix/,'
627 will add 'prefix/' to all file names stored in foo.tar.
629 ** --strip-components option works when deleting and comparing. In previous
630 versions it worked only with --extract.
632 ** New option --show-transformed-names enables display of transformed file
633 or archive. It generalizes --show-stored-names option, introduced in
634 1.15.90. In particular, when creating an archive in verbose mode, it lists
635 member names as stored in the archive, i.e., with any eventual prefixes
636 removed and file name transformations applied. The option is useful,
637 for example, while comparing 'tar cv' and 'tar tv' outputs.
639 ** New incremental snapshot file format keeps information about file names
640 as well as that about directories.
642 ** The --checkpoint option takes an optional argument specifying the number
643 of records between the two successive checkpoints. Optional dot
644 starting the argument intructs tar to print dots instead of textual
647 ** The --totals option can be used with any tar operation (previous versions
648 understood it only with --create). If an argument to this option is
649 given, it specifies the signal upon delivery of which the statistics
650 is to be printed. Both forms of this option (with and without
651 argument) can be given to in a single invocation of tar.
654 ** Detect attempts to update compressed archives.
657 version 1.15.90 - Sergey Poznyakoff, 2006-02-19
661 ** Any number of -T (--files-from) options may be used in the command line.
662 The file specified with -T may include any valid 'tar' options,
663 including another -T option.
664 Compatibility note: older versions of tar would only recognize -C
665 as an option name within the file list file. Now any file whose name
666 starts with - is handled as an option. To insert file names starting with
667 dash, use the --add-file option.
669 ** List files containing null-separated file names are detected and processed
670 automatically. It is no longer necessary to give the --null option.
672 ** New option --no-unquote disables the unquoting of input file names.
673 This is useful for processing output from 'find dir -print0'.
674 An orthogonal option --unquote is provided as well.
676 ** New option --test-label tests the archive volume label.
677 If an argument is specified, the label is compared against its value.
678 Tar exits with code 0 if the two strings match, and with code 2 if
681 If no argument is given, the --verbose option is implied. In this case,
682 tar prints the label name if present and exits with code 0.
684 ** New option --show-stored-names. When creating an archive in verbose mode,
685 it lists member names as stored in the archive, i.e., with any eventual
686 prefixes removed. The option is useful, for example, while comparing
687 'tar cv' and 'tar tv' outputs.
689 ** New option --to-command pipes the contents of archive members to the
692 ** New option --atime-preserve=system, which uses the O_NOATIME feature
693 of recent Linux kernels to avoid some problems when preserving file
696 ** New option --delay-directory-restore delays restoring modification times
697 and permissions of extracted directories until the end of extraction.
698 This is necessary for restoring from archives with unusual member
699 ordering (in particular, those created with --no-recursion option).
700 This option is implied when restoring from incremental archives.
702 ** New option --restrict prohibits use of some potentially harmful tar
703 options. Currently it disables '!' escape in multi-volume name menu.
705 ** New options --quoting-style and --quote-chars control the way tar
706 quotes member names on output. The --quoting-style takes an argument
707 specifying the quoting style to use (literal, shell, shell-always,
708 c, escape, locale, clocale). The argument to --quote-chars is a string
709 specifying characters to quote, even if the selected quoting style
710 would not quote them otherwise. The option --no-quote-chars is
711 provided to disable quoting certain characters.
713 ** The end-of-volume script (introduced with --info-script option) can
714 get current archive name from the environment variable TAR_ARCHIVE and
715 the volume number from the variable TAR_VOLUME. It can alter the
716 archive name by writing new name to the file descriptor 3.
718 ** Better support for full-resolution time stamps. Tar cannot restore
719 time stamps to full nanosecond resolution, though, until the kernel
720 guys get their act together and give us a system call to set file time
721 stamps to nanosecond resolution.
723 ** The -v option now prints time stamps only to 1-minute resolution,
724 not full resolution, to avoid using up too many output columns.
725 Nanosecond resolution is now supported, but that would be too much.
729 ** Allow non-option arguments to be interspersed with options.
730 ** When extracting or listing archives in old GNU format, tar
731 used to read an extra block of data after a long name header
732 if length of the member name was divisible by block size (512).
733 Consequently, the file pointer was set off and the next member
734 was not processed correctly.
735 ** Previous version created invalid archives when files shrink
737 ** Compare mode (tar d) hung when trying to compare file contents.
738 ** Previous versions in certain cases failed to restore directory
740 ** When creating an archive, do not attempt to store files whose
741 meta-data cannot be stored in the header due to format limitations
742 (for ustar and v7 formats).
743 ** The --version option now also outputs information about copyright,
744 license, and credits. This reverts to the behavior of tar 1.14 and
745 earlier, and conforms to the GNU coding standards. The --license (-L)
746 option introduced in tar 1.15 has been removed, since it's no longer
750 version 1.15.1 - Sergey Poznyakoff, 2004-12-21
752 This version fixes a bug introduced in 1.15 which caused
753 tar to refuse to extract files from standard input.
756 version 1.15 - Sergey Poznyakoff, 2004-12-20
758 * Compressed archives are recognised automatically, it is no longer
759 necessary to specify -Z, -z, or -j options to read them. Thus, you can
760 now run 'tar tf archive.tar.gz'.
762 * When restoring incremental dumps, --one-file-system option
763 prevents directory hierarchies residing on different devices
766 With the previous versions of tar it was dangerous to create
767 incremental dumps with --one-file-system option, since they
768 would recursively remove mount points when restoring from the
769 back up. This change fixes the bug.
771 * Renamed --strip-path to --strip-components for consistency with
774 * Skipping archive members is sped up if the archive media supports
777 * Restore script starts restoring only if it is given --all (-a) option,
778 or some patterns. This is to prevent accidental restores.
780 * 'tar --verify' prints a warning if during archive creation some of
781 the file names had their prefixes stripped off.
783 * New option --exclude-caches instructs tar to exclude cache directories
784 automatically on archive creation. Cache directories are those
785 containing a standardized tag file, as specified at:
787 http://www.brynosaurus.com/cachedir/spec.html
789 * New configure option --with-rmt allows to specify full path name to
790 the 'rmt' utility. This supersedes DEFAULT_RMT_COMMAND variable
791 introduced in version 1.14
793 * New configure variable DEFAULT_RMT_DIR allows to specify the directory
794 where to install 'rmt' utility. This is necessary since modifying
795 --libexecdir as was suggested for version 1.14 produced a side effect: it
796 also modified installation prefix for backup scripts (if
797 --enable-backup-scripts was given).
800 ** Fixed flow in recognizing files to be included in incremental dumps.
801 ** Correctly recognize sparse archive members when used with -T option.
802 ** GNU multivolume headers cannot store filenames longer than 100 characters.
803 Do not allow multivolume archives to begin with such filenames.
804 ** If a member with link count > 2 was stored in the archive twice,
805 previous versions of tar were not able to extract it, since they
806 were trying to link the file to itself, which always failed and
807 lead to removing the already extracted copy. Preserve the first
808 extracted copy in such cases.
809 ** Restore script was passing improper argument to tar --listed option (which
810 didn't affect the functionality, but was logically incorrect).
811 ** Fixed verification of created archives.
812 ** Fixed unquoting of file names containing backslash escapes (previous
813 versions failed to recognize \a and \v).
814 ** When attempting to delete a non-existing member from the archive, previous
815 versions of tar used to overwrite last archive block with zeroes.
818 version 1.14 - Sergey Poznyakoff, 2004-05-11
820 * Added support for POSIX.1-2001 and ustar archive formats.
821 * New option --format allows to select the output archive format
822 * The default output format can be selected at configuration time
823 by presetting the environment variable DEFAULT_ARCHIVE_FORMAT.
824 Allowed values are GNU, V7, OLDGNU and POSIX.
825 * New option --strip-path allows to cut off a given number of
826 path elements from the name of the file being extracted.
828 * New options --index-file, --no-overwrite-dir. The --overwrite-dir
829 option is now the default; use --no-overwrite-dir if you prefer
830 the previous default behavior.
832 * The semantics of -o option is changed. When extracting, it
833 does the same as --no-same-owner GNU tar option. This is compatible
834 with UNIX98 tar. Otherwise, its effect is the same as that of
835 --old-archive option. This latter is deprecated and will be removed
838 * New option --check-links prints a message if not all links are dumped
839 for a file being archived. This corresponds to the UNIX98 -l option.
840 The current semantics of the -l option is retained for compatibility
841 with previous releases, however such usage is strongly deprecated as
842 the option will change to its UNIX98 semantics in the future releases.
844 * New option --occurrence[=N] can be used in conjunction with one of
845 the subcommands --delete, --diff, --extract or --list when a list of
846 files is given either on the command line or via -T option. This
847 option instructs tar to process only the Nth occurrence of each named
848 file. N defaults to 1, so 'tar -x -f archive --occurrence filename'
849 extracts the first occurrence of 'filename' from 'archive'
850 and terminates without scanning to the end of the archive.
852 * New option --pax-option allows to control the handling of POSIX
853 keywords in 'pax' extended headers. It is equivalent to 'pax'
856 * --incremental and --listed-incremental options work correctly on
857 individual files, as well as on directories.
859 * New scripts: backup (replaces old level-0 and level-1) and restore.
860 The scripts are compiled and installed if --enable-backup-scripts
861 option is given to configure.
863 * By default tar searches "rmt" utility in "$prefix/libexec/rmt",
864 which is consistent with the location where the version of "rmt"
865 included in the package is installed. Previous versions of tar
866 used "/etc/rmt". To install "rmt" to its traditional location,
867 run configure with option --libexecdir=/etc. Otherwise, if you
868 already have rmt installed and wish to use it, instead of the
869 shipped in version, set the variable DEFAULT_RMT_COMMAND to
870 the full path name of the utility, e.g., ./configure
871 DEFAULT_RMT_COMMAND=/etc/rmt.
873 Notice also that the full path name of the "rmt" utility to
874 use can be set at runtime, by giving option --rmt-command to
877 * Removed obsolete command line options:
878 ** --absolute-paths superseded by --absolute-names
879 ** --block-compress is not needed any longer
880 ** --block-size superseded by --blocking-factor
881 ** --modification-time superseded by --touch
882 ** --read-full-blocks superseded by --read-full-records
883 ** --record-number superseded by --block-number
884 ** --version-control superseded by --backup
886 * New message translations fi (Finnish), gl (Galician), hr (Croatian),
887 hu (Hungarian), ms (Malaysian), nb (Norwegian), ro (Romanian), sk
888 (Slovak), zh_CN (Chinese simplified), zh_TW (Chinese traditional).
889 The code 'no' for Norwegian (Bokmål) has been withdrawn; use 'nb' instead.
894 version 1.13.25 - Paul Eggert, 2001-09-26
899 version 1.13.24 - Paul Eggert, 2001-09-22
901 * New option --overwrite-dir.
902 * Fixes for buffer overrun, porting, and copyright notice problems.
903 * The message translations for Korean are available again.
906 version 1.13.23 - Paul Eggert, 2001-09-13
908 * Bug, porting, and copyright notice fixes.
911 version 1.13.22 - Paul Eggert, 2001-08-29
916 version 1.13.21 - Paul Eggert, 2001-08-28
918 * Porting and copyright notice fixes.
921 version 1.13.20 - Paul Eggert, 2001-08-27
923 * Some bugs were fixed:
925 - hard links to symbolic links
927 * New option --recursion (the default) that is the inverse of --no-recursion.
929 * New options --anchored, --ignore-case, --wildcards,
930 --wildcards-match-slash, and their negations (e.g., --no-anchored).
931 Along with --recursion and --no-recursion, these options control how
932 exclude patterns are interpreted.
934 * The default interpretation of exclude patterns is now --no-anchored
935 --no-ignore-case --recursion --wildcards --wildcards-match-slash.
936 This is a quiet change to the semantics of --exclude. The previous
937 semantics were a failed attempt at backward compatibility but it
938 became clear that the semantics were puzzling and did not satisfy
939 everybody. Rather than continue to try to revive that dead horse we
940 thought it better to substitute cleaner semantics, with options so
941 that you can change the behavior more to your liking.
943 * New message translations for Indonesian and Turkish.
944 The translation for Korean has been withdrawn due to encoding errors.
945 It will be reissued once those are fixed.
948 version 1.13.19 - Paul Eggert, 2001-01-13
950 * The -I option has been withdrawn, as it was buggy and confusing.
951 Eventually it is planned to be reintroduced, with the same meaning as -T.
953 * With an option like -N DATE, if DATE starts with "/" or ".", it is taken
954 to be a file name; the last-modified time of that file is used as the date.
957 version 1.13.18 - Paul Eggert, 2000-10-29
959 * Some security problems have been fixed. 'tar -x' now modifies only
960 files under the working directory, unless you also specify an unsafe
961 option like --absolute-names or --overwrite.
963 * The short name of the --bzip option has been changed to -j,
964 and -I is now an alias for -T, for compatibility with Solaris tar.
966 * The manual is now distributed under the GNU Free Documentation License.
968 * The new environment variable TAR_OPTIONS holds default command-line options.
970 * The --no-recursion option now affects extraction too.
972 * The wording in some diagnostics has been changed slightly.
974 * Snapshot files now record whether each file was accessed via NFS.
975 The new file format is upward- and downward-compatible with the old.
977 * New language supported: da.
979 * Compilation by traditional (K&R) C compilers is no longer supported.
980 If you still use such a compiler, please use GCC instead.
982 * This version of tar works best with GNU gzip test version 1.3 or later.
983 Please see <ftp://alpha.gnu.org/gnu/gzip/>.
985 * 'tar --delete -f -' now works again.
988 version 1.13.17 - Paul Eggert, 2000-01-07.
990 * 'tar --delete -f -' is no longer allowed; it was too buggy.
991 * Diagnostic messages have been made more regular and consistent.
994 version 1.13.16 - Paul Eggert, 1999-12-13.
996 * By default, tar now refuses to overwrite an existing file when
997 extracting files from an archive; instead, it removes the file
998 before extracting it. If the existing file is a symbolic link, the
999 link is removed and not the pointed-to file. There is one
1000 exception: existing nonempty directories are not removed, nor are
1001 their ownerships or permissions extracted. This fixes some
1002 longstanding security problems.
1004 The new --overwrite option enables the old default behavior.
1006 For regular files, tar implements this change by using the O_EXCL
1007 option of 'open' to ensure that it creates the file; if this fails, it
1008 removes the file and tries again. This is similar to the behavior of
1009 the --unlink-first option, but it is faster in the common case of
1010 extracting a new directory.
1012 * By default, tar now ignores file names containing a component of '..'
1013 when extracting, and warns about such file names when creating an archive.
1014 To enable the old behavior, use the -P or --absolute-names option.
1016 * Tar now handles file names with multibyte encodings (e.g., UTF-8, Shift-JIS)
1017 correctly. It relies on the mbrtowc function to handle multibyte characters.
1019 * The file generated by -g or --listed-incremental now uses a format
1020 that is independent of locale, so that users need not worry about
1021 locale when restoring a backup. This is needed for proper support
1022 of multibyte characters. Old-format files can still be read, and
1023 older versions of GNU tar can read new-format files, unless member
1024 names have multibyte chars.
1026 * Many diagnostics have been changed slightly, so that file names are
1027 now output unambiguously. File names in diagnostics now are either
1028 `quoted like this' (in the default C locale) or are followed by
1029 colon, newline, or space, depending on context. Unprintable
1030 characters are escaped with a C-like backslash conventions.
1031 Terminating characters (e.g., close-quote, colon, newline)
1032 are also escaped as needed.
1034 * tar now ignores socket files when creating an archive.
1035 Previously tar archived sockets as fifos, which caused problems.
1038 version 1.13.15 - Paul Eggert, 1999-12-03.
1040 * If a file's ctime changes when being archived, report an error.
1041 Previously tar looked at mtime, which missed some errors.
1044 version 1.13.14 - Paul Eggert, 1999-11-07.
1046 * New translations ja, pt_BR.
1047 * New options --help and --version for rmt.
1048 * Ignore Solaris door files when creating an archive.
1051 version 1.13.13 - Paul Eggert, 1999-10-11.
1053 * Invalid headers in tar files now elicit errors, not just warnings.
1054 * 'tar --version' output conforms to the latest GNU coding standards.
1055 * If you specify an invalid date, 'tar' now substitutes (time_t) -1.
1056 * 'configure --with-dmalloc' is no longer available.
1059 version 1.13.12 - Paul Eggert, 1999-09-24.
1061 * 'tar' now supports hard links to symbolic links.
1063 * New options --no-same-owner, --no-same-permissions.
1065 * --total now also outputs a human-readable size, and a throughput value.
1067 * 'tar' now uses two's-complement base-256 when outputting header
1068 values that are out of the range of the standard unsigned base-8
1069 format. This affects archive members with negative or huge time
1070 stamps or uids, and archive members 8 GB or larger. The new tar
1071 archives cannot be read by traditional tar, or by older versions of
1072 GNU tar. Use the --old-archive option to revert to the old
1073 behavior, which uses unportable representations for negative values,
1074 and which rejects large files.
1076 * On 32-bit hosts, 'tar' now assumes that an incoming time stamp T in
1077 the range 2**31 <= T < 2**32 represents the negative time (T -
1078 2**32). This behavior is nonstandard and is not portable to 64-bit
1079 time_t hosts, so 'tar' issues a warning.
1081 * 'tar' no longer gives up extracting immediately upon discovering
1082 that an archive contains garbage at the end. It attempts to extract
1083 as many files as possible from the good data before the garbage.
1085 * A read error now causes a nonzero exit status, not just a warning.
1087 * Some diagnostics have been reworded for consistency.
1090 version 1.13.11 - Paul Eggert, 1999-08-23.
1092 * The short name of the --bzip option has been changed to -I,
1093 for compatibility with paxutils.
1095 * -T /dev/null now matches nothing; previously, it matched anything
1096 if no explicit operands were given.
1098 * The '--' option now works the same as with other GNU utilities;
1099 it causes later operands to be interpreted as file names, not options,
1100 even if they begin with '-'.
1102 * For the --newer and --after-date options, the table of time zone
1103 abbreviations like 'EST' has been updated to match current practice.
1104 Also, local time abbreviations are now recognized, even if they are
1105 not in tar's hardwired table. Remember, though, that you should use
1106 numeric UTC offsets like '-0500' instead of abbreviations like
1107 'EST', as abbreviations are not standardized and are ambiguous.
1110 version 1.13.10 - Paul Eggert, 1999-08-20.
1112 * 'tar' now uses signed base-64 when outputting header values that are
1113 out of the range of the standard unsigned base-8 format. [This
1114 change was superseded in 1.13.12, described above.]
1117 version 1.13.9 - Paul Eggert, 1999-08-18.
1119 * 'tar' now writes two zero blocks at end-of-archive instead of just one.
1120 POSIX.1 requires this, and some other 'tar' implementations check for it.
1122 * 'tar' no longer silently accepts a block containing nonzero checksum bytes
1125 * 'tar' now reads buggy tar files that have a null byte at the start of a
1126 numeric header field.
1129 version 1.13.8 - Paul Eggert, 1999-08-16.
1131 * For compatibility with traditional 'tar', intermediate directories
1132 created automatically by root are no longer given the uid and gid of
1133 the original file or directory.
1136 version 1.13.7 - Paul Eggert, 1999-08-14.
1138 * --listed-incremental and --newer are now incompatible options.
1140 * When creating an archive, leading './' is no longer stripped,
1141 to match traditional tar's behavior (and simplify the documentation).
1143 * --diff without --absolute-names no longer falls back on absolute names.
1146 version 1.13.6 - Paul Eggert, 1999-08-11.
1148 * An --exclude pattern containing / now excludes a file only if it matches an
1149 initial prefix of the file name; a pattern without / continues to
1150 exclude a file if it matches any file name component.
1152 * The protocol for talking to rmt has been extended slightly.
1153 Open flags are now communicated in symbolic format as well as numeric.
1154 The symbolic format (e.g., "O_WRONLY|O_CREAT|O_TRUNC") is for portability
1155 when rmt is operating on a different operating system from tar.
1156 The numeric format is retained, and rmt uses it if symbolic format is absent,
1157 for backward compatibility with older versions of tar and rmt.
1159 * When writing GNU tar format headers, tar now uses signed base-64
1160 for values that cannot be represented in unsigned octal.
1161 This supports larger files (2**66 - 1 bytes instead of 2**33 - 1 bytes),
1162 larger uids, negative time stamps, etc.
1164 * When extracting files with unknown ownership, tar now looks up the
1165 uid and gid "nobody" on hosts whose headers do not define UID_NOBODY
1166 and GID_NOBODY, and falls back on uid/gid -2 if there is no "nobody".
1168 * tar -t --numeric-owner now prints numeric uids and gids, not symbolic.
1170 * New option -y or --bzip2 for bzip2 compression, by popular request.
1173 version 1.13.5 - Paul Eggert, 1999-07-20.
1175 * Do the delayed updates of file metadata even after a fatal error.
1178 version 1.13.4 - Paul Eggert, 1999-07-20.
1180 * Do not chmod unless we are root or the -p option was given;
1181 this matches historical practice.
1184 version 1.13.3 - Paul Eggert, 1999-07-16.
1186 * A path name is excluded if any of its file name components matches an
1187 excluded pattern, even if the path name was specified on the command line.
1188 Also see 1.13.6 for later changes in this area.
1191 version 1.13.2 - Paul Eggert, 1999-07-14.
1193 * Bug reporting address changed to <bug-tar@gnu.org>.
1196 version 1.13.1 - Paul Eggert, 1999-07-12.
1200 version 1.13 - Paul Eggert, 1999-07-08.
1202 * Support for large files, e.g., files larger than 2 GB on many 32-bit hosts.
1203 Also, support for larger uids, device ids, etc.
1204 * Many bug fixes and porting fixes.
1205 * This release is only for fixes. A more ambitious test release,
1206 with new features, is available as part of the paxutils. Please see:
1207 ftp://alpha.gnu.org/gnu/paxutils/
1208 The fixes in this release are intended to be merged with paxutils
1209 at some point, but they haven't been merged yet.
1210 * An interim GNU tar alpha had new --bzip2 and --ending-file options,
1211 but they have been removed to maintain compatibility with paxutils.
1212 Please try --use=bzip2 instead of --bzip2.
1214 Version 1.12 - François Pinard, 1997-04.
1217 * Use shell globbing patterns for --label, instead of regular expressions.
1218 * Do not quote anymore internally over the quoting done by the shell.
1221 * Offer internationalization capabilities of most recent GNU gettext.
1222 * Messages available in many more languages, thanks to all translators!
1223 * Usage of ISO 8601 dates in listings, instead of local American dates.
1224 * More normalization and cleanup in error messages.
1227 * For helping using tar with find, offer a --no-recursion option.
1228 * Implement --numeric-owner for ignoring symbolic names at create time.
1229 * New --owner, --group --mode options, still preliminary.
1230 * Recognize creating an archive on /dev/null, so Amanda works faster.
1231 * Object to the creation of an empty archive (like in 'tar cf FILE').
1232 * Barely start implementing --posix and POSIXLY_CORRECT.
1235 * Make a better job at restoring file and directory attributes.
1236 * Automatically attempt deleting existing files when in the way.
1237 * Option --unlink-first (-U) removes most files prior to extraction.
1238 * Option --recursive-unlink removes non-empty directories when in the way.
1239 * Option --numeric-owner ignores owner/group names, it uses UID/GID instead.
1240 * Use global umask when creating missing intermediate directories.
1241 * When symlinks are not available, extract symbolic links as hard links.
1242 * Diagnose extraction of contiguous files as regular files.
1243 * New --backup, --suffix and --version-control options.
1246 * Better support of huge archives with --tape-length and --totals.
1247 * Rename option --read-full-blocks (-B) to --read-full-records (-B).
1248 * Rename option --block-size (-b) to --blocking-factor (-b).
1249 * Rename option --record-number (-R) to --block-number (-R).
1250 * With --block-number (-R), report null blocks and end of file.
1251 * Implement --record-size for introducing a size in bytes.
1252 * Delete --block-compress option and rather decide it automatically.
1253 * Rename option --modification-time to --touch.
1255 Many bugs are squashed, while others still run free.
1257 Version 1.11.8 - François Pinard, 1995-06.
1259 * Messages available in French, German, Portuguese and Swedish.
1260 * The distribution provides a rudimentary Texinfo manual.
1261 * The device defaults to stdin/stdout, unless overridden by the installer.
1262 * Option --sparse (-S) should work on more systems.
1263 * Option --rsh-command may select an alternative remote shell program.
1265 Most changes are internal, and should yield better portability.
1267 Version 1.11.2 - Michael Bushnell, 1993-03.
1269 * Changes in backup scripts: cleaned up considerably; notices error
1270 conditions better over rsh; DUMP_REMIND_SCRIPT is now an option in
1271 backup-specs; new file dump-remind is an example of a
1274 * Superfluous "Reading dirname" was a bug; fixed.
1276 * Incompatibility problems with a bug on Solaris are fixed.
1278 * New option --gzip (aliases are --ungzip and -z); calls gzip instead
1279 of compress. Also, --use-compress-program lets you specify any
1280 compress program. --compress-block is renamed --block-compress and
1281 now requires one of the three compression options to be specified.
1283 * Several error messages are cleaned up.
1285 * Directory owners are now set properly when running as root.
1287 * Provide DUMP_REMIND_SCRIPT in backup-specs as a possible option
1290 * Behave better with broken rmt servers.
1292 * Dump scripts no longer use --atime-preserve; this causes a nasty probem.
1294 * Several Makefile cleanups.
1296 Version 1.11.1 - Michael Bushnell, 1992-09.
1300 Version 1.11 - Michael Bushnell, 1992-09.
1301 Version 1.10.16 - 1992-07.
1302 Version 1.10.15 - 1992-06.
1303 Version 1.10.14 - 1992-05.
1304 Version 1.10.13 - 1992-01.
1308 * Now uses GNU standard configure, generated by Autoconf.
1310 * Long options now use '--'; use of '+' is deprecated and support
1311 for it will eventually be removed.
1313 * New option --null causes filenames read by -T to be
1314 null-terminated, and causes -C to be ignored.
1316 * New option --remove-files deletes files (but not directories)
1317 after they are added to the archive.
1319 * New option --ignore-failed-read prevents read-errors from affecting
1322 * New option --checkpoint prints occasional messages as the tape
1323 is being read or written.
1325 * New option --show-omitted-dirs prints the names of directories
1326 omitted from the archive.
1328 * Some tape drives which use a non-standard method of indicating
1329 end-of-tape now work correctly with multi-tape archives.
1331 * --volno-file: Read the volume number used in prompting the user
1332 (but not in recording volume ID's on the archive) from a file.
1334 * When using --multi-volume, you can now give multiple -f arguments;
1335 the various tape drives will get used in sequence and then wrap
1336 around to the beginning.
1338 * Remote archive names no longer have to be in /dev: any file with a
1339 ':' is interpreted as remote. If new option --force-local is given,
1340 then even archive files with a ':' are considered local.
1342 * New option --atime-preserve restores (if possible) atimes to
1343 their original values after dumping the file.
1345 * No longer does tar confusingly dump "." when you don't tell it
1348 * When extracting directories, tar now correctly restores their
1349 modification and access times.
1351 * Longnames support is redone differently--long name info directly
1352 precedes the long-named file or link in the archive, so you no
1353 longer have to wait for the extract to hit the end of the tape for
1356 Version 1.10 - Michael Bushnell, 1991-07.
1358 * Filename to -G is optional. -C works right. Names +newer and
1359 +newer-mtime work right.
1361 * -g is now +incremental, -G is now +listed-incremental.
1363 * Sparse files now work correctly.
1365 * +volume is now called +label.
1367 * +exclude now takes a filename argument, and +exclude-from does
1368 what +exclude used to do.
1370 * Exit status is now correct.
1372 * +totals keeps track of total I/O and prints it when tar exits.
1374 * When using +label with +extract, the label is now a regexp.
1376 * New option +tape-length (-L) does multi-volume handling like BSD
1377 dump: you tell tar how big the tape is and it will prompt at that
1378 point instead of waiting for a write error.
1380 * New backup scripts level-0 and level-1 which might be useful
1381 to people. They use a file "backup-specs" for information, and
1382 shouldn't need local modification. These are what we use to do
1383 all our backups at the FSF.
1385 Version 1.09 - Jay Fenlason, 1990-10.
1386 Version 1.08 - Jay Fenlason, 1990-01.
1387 Versions 1.07 back to 1.00 by Jay Fenlason.
1389 * See ChangeLog for more details.
1393 Copyright 1994-2001, 2003-2010, 2013 Free Software Foundation, Inc.
1395 This file is part of GNU tar.
1397 GNU tar is free software; you can redistribute it and/or modify
1398 it under the terms of the GNU General Public License as published by
1399 the Free Software Foundation; either version 3 of the License, or
1400 (at your option) any later version.
1402 GNU tar is distributed in the hope that it will be useful,
1403 but WITHOUT ANY WARRANTY; without even the implied warranty of
1404 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1405 GNU General Public License for more details.
1407 You should have received a copy of the GNU General Public License
1408 along with this program. If not, see <http://www.gnu.org/licenses/>.
1412 paragraph-separate: "[
\f]*$"
1413 eval: (add-hook 'write-file-hooks 'time-stamp)
1414 time-stamp-start: "changes. "
1415 time-stamp-format: "%:y-%02m-%02d"
1416 time-stamp-end: "\n"