GNUTAR(1)GNUTAR(1)NAMEgnutar - GNU tape archiver
SYNOPSIS
tar [ options ] [ name ... ]
DESCRIPTIONgnutar saves and restores multiple files in a single archive (usually a
magnetic tape). It was created by John Gilmore for the GNU Project and
distributed by the Free Software Foundation. For complete documentation
of gnutar, see the GNU Tape Archiver Manual in
/usr/lib/emacs/info/gnutar.
You can use gnutar in the same way as the UNIX tar command. You specify
a single-letter option to perform the following functions: create an
archive, extract files from an archive, modify an archive, or list the
contents of an archive. The other argument to gnutar is one or more
file or directory names specifying which files to dump or restore. In
all cases, a directory name refers to the files and (recursively)
subdirectories of that directory.
gnutar does not require that you precede an option with a dash (-).
This means that the commands gnutar c and gnutar-c both create an
archive. gnutar also provides named options that can be used with a
single-letter options or instead of a single-letter option. A named
option is preceded with two dashes (--). Other advantages of gnutar
include: path names up to 1024 characters long, archival of device
files, and built-in file compressiondecompression.
Here are the common single-letter options for gnutar and the UNIX tar
command (with the equivalent named options for gnutar also listed):
c --create Create a new tape; writing begins on the
beginning of the tape instead of after the last
file.
r --append The named files are written on the end of the
tape. The c function implies this.
t --list The names of the specified files are listed
each time they occur on the tape. If no file
argument is given, all of the names on the tape
are listed.
u --update The named files are added to the tape if either
they are not already there or have been
modified since last put on the tape.
x --extract --get The named files are extracted from the tape.
If the named file matches a directory whose
contents had been written onto the tape, this
directory is (recursively) extracted. The
owner, modification time, and mode are restored
(if possible). If no file argument is given,
the entire content of the tape is extracted.
Note that if multiple entries specifying the
same file are on the tape, the last one
overwrites all earlier.
Here are the options that only gnutar supports:
-A --catenate --concatenate
Append tar files to an archive.
-d --diff --compare Find differences between the archive and the
file system.
--delete Delete files from the archive (not used on
magnetic tapes).
--help Display a list of gnutar options.
You can specify one or more single-letter modifiers (as well as named
modifiers) to the options already listed. Here are the common single-
letter option modifiers for gnutar and the UNIX tar command (with the
equivalent named modifiers for gnutar also listed):
b --block-sizegnutar uses the next argument as the blocking
factor for tape records.
B --read-full-blocks Forces input and output blocking so that gnutar
can work across a communications channel where
the blocking may not be maintained.
C --directory Allow multiple directories not related by a
close common parent to be archived using short
relative path names.
f --filegnutar uses the next argument as the name of
the archive instead of a default archive name.
If the name of the file is `-', gnutar writes
to standard output or reads from standard
input, whichever is appropriate.
h --dereference Force gnutar to follow symbolic links as if
they were normal files or directories.
Normally, gnutar does not follow symbolic
links.
l --one-file-system Force gnutar will complain if it cannot resolve
all of the links to the files dumped. If this
is not specified, no error messages are
printed.
m --modification-time Force gnutar to not restore the modification
times. The modification time will be the time
of extraction.
o --old-archive --portability
On output, gnutar normally places information
specifying owner and modes of directories in
the archive.
p --same-permissions --preserve-permissions
This modifier says to restore files to their
original modes, ignoring the present umask(2).
Setuid and sticky information will also be
restored to the super-user.
v --verbose Normally gnutar does its work silently. The
verbose option makes gnutar print the name of
each file it treats preceded by the function
letter. With the t function, the verbose
option gives more information about the tape
entries than just their names.
w --interactive --confirmation
gnutar prints the action to be taken followed
by file name, then wait for user confirmation.
If a word beginning with `y' is given, the
action is done. Any other input means don't do
it.
0 ... 7 Specify the drive where the magnetic tape is
mounted.
Here are modifiers that only gnutar supports:
--atime-preserve Do not change access times on dumped files.
--block-compress Block the output of compression program for
tapes.
--checkpoint Print directory names while reading the
archive.
--exclude file Exclude file.
--force-local Force the archive file to be local.
-F --info-script --new-volume-script
Invoke the script script at end of each tape
(implies -M).
-G --incremental Create, list, or extract an old GNU-format
incremental backup.
-g --listed-incremental file
Create, list, or extract a new GNU-format
incremental backup.
-i --ignore-zeros Ignore blocks of zeros in the archive (normally
means EOF).
--ignore-failed-read
Do not exit with non-zero status on unreadable
files.
-k --keep-old-files Don't overwrite existing files in the archive.
-K --starting-file file
Begin at file in the archive.
-L --tape-length N Change tapes after writing N*1024 bytes.
-M --multi-volume Create, list, or extract a multi-volume
archive.
-N --after-date --newer Store only files newer than date.
-O --to-stdout Extract files to standard output.
-P --absolute-paths Do not strip leading slash marks (//) from file
names
--preserve Preserve permissions and file order (like -p
-s).
-R --record-number Show record number within archive with each
message.
--remove-files Remove files after adding them to the archive.
-s --same-order --preserve-order
Sort the list of names to extract to match the
archive.
--same-owner Create extracted files with the same ownership.
-S --sparse Handle sparse files efficiently.
--totals Print total bytes written with --create.
-T --files-from file
Get names to extract, or create from file.
--use-compress-program program
Filter the archive through program (which must
accept -d).
-V --label name Create an archive with volume name name.
--version Print the gnutar version number
-W --verify Attempt to verify the archive after writing it.
-X --exclude-from file
Exclude files listed in file.
-Z --compress --uncompress
Filter the archive through compress.
-z --gzip --ungzip
Filter the archive through gzip.
SEE ALSOtar(1)Free Software Foundation, Inc. August 10, 1993 GNUTAR(1)
