.\" Copyright (c) 1991, 1992, 1993 Free Software Foundation -*- nroff -*- .\" See section COPYING for conditions for redistribution .\" .\" Written by John F. Woods .\" .\" $NetBSD: gtar.1,v 1.1.1.2 1999/09/18 14:50:14 kim Exp $ .\" from NetBSD: tar.1,v 1.8 1997/06/06 07:59:54 jeremy Exp .\" .Dd 6 August 1994 .Os NetBSD .Dt GTAR 1 .Sh NAME .Nm gtar .Nd GNU tape archiver; manipulate "tar" archive files .Sh SYNOPSIS .Nm .Op Cm Bq - .Op Cm bundled-options .Op Ar [gnu-style-flags] .Op Ar tarfile .Op Ar blocksize .Op Ar exclude-file .Op Ar filenames .Op Fl C Ar directory-name .Sh DESCRIPTION .Nm is short for .Dq tape archiver, so named for historical reasons; the .Nm program creates, adds files to, or extracts files from an archive file in .Dq tar format, called a .Ar tarfile . A tarfile is often a magnetic tape, but can be a floppy diskette or any regular disk file. .Pp The first argument word of the .Nm command line is usually a command word of bundled function and modifier letters, optionally preceeded by a dash; it must contain exactly one function letter from the set .Cm A , .Cm c , .Cm d , .Cm r , .Cm t , .Cm u , .Cm x , for append, create, difference, replace, table of contents, update, and extract (further described below). The command word can also contain other function modifiers described below, some of which will take arguments from the command line in the order they are specified in the command word (review the EXAMPLES section). Functions and function modifiers can also be specified with the GNU argument convention (preceeded by two dashes, one function or modifier per word. Command-line arguments that specify files to add to, extract from, or list from an archive may be given as shell pattern matching strings. .Sh FUNCTIONS Exactly one of the following functions must be specified. .Pp .Bl -tag -width "--concatenate" -compact .It Fl A .It Fl -catenate .It Fl "-concatenate" Append the contents of named file, which must itself be a tar archive, to the end of the archive (erasing the old end-of-archive block). This has the effect of adding the files contained in the named file to the first archive, rather than adding the second archive as an element of the first. .Em Note: This option requires a rewritable tarfile, and therefore does not work on quarter-inch cartridge tapes. .It Fl c .It Fl -create Create a new archive (or truncates an old one) and writes the named files to it. .It Fl d .It Fl -diff .It Fl -compare Find differences between files in the archive and corresponding files in the file system. .It Fl -delete Delete named files from the archive (Does not work on quarter-inch tapes). .It Fl r .It Fl -append Append files to the end of an archive (Does not work on quarter-inch tapes). .It Fl t .It Fl -list List the contents of an archive; if filename arguments are given, only those files are listed, otherwise the entire table of contents is listed. .It Fl u .It Fl -update Append the named files if the on-disk version has a modification date more recent than their copy in the archive (if any). Does not work on quarter-inch tapes. .It Fl x .It Fl -extract .It Fl -get Extract files from an archive. The owner, modification time, and file permissions are restored, if possible. If no .Ar file arguments are given, extract all the files in the archive. If a .Ar filename argument matches the name of a directory on the tape, that directory and its contents are extracted (as well as all directories under that directory). If the archive contains multiple entries corresponding to the same file (see the .Fl -append command above), the last one extracted will overwrite all earlier versions. .El .Sh OPTIONS The other options to .Nm may be combined arbitrarily; single-letter options may be bundled in with the command word. Verbose options which take arguments will be followed by the argument; single-letter options will consume successive command line arguments (see the .Sx EXAMPLES below). .Pp .Bl -tag -width "--preserve-permissions" -compact .It Fl -help Prints a message listing and briefly describing all the command options to tar. .It Fl -atime-preserve Restore the access times on files which are written to tape (note that this will change the inode-change time!). .It Fl b .It Fl -block-size Ar number Sets the block size for reading or writing to N 512-byte blocks. .It Fl B .It Fl -read-full-blocks Re-assemble short reads into full blocks (for reading 4.2BSD pipes). .It Fl C Ar directory .It Fl -directory Ar directory Change to .Ar directory for extraction. .It Fl -checkpoint Print directory names while reading the archive. .It Fl f Ar [hostname:]file .It Fl -file Ar [hostname:]file Read or write the specified .Ar file .Po default is Pa /dev/rst0 Pc . If a .Ar hostname is specified, .Nm will use .Xr rmt 8 to read or write the specified .Ar file on a remote machine. If the given .Ar file is .Ql - , then .Nm uses stdin or stdout. .It Fl F Ar file .It Fl -info-script Ar file .It Fl -new-volume-script Ar file Run a script at the end of each archive volume (implies .Fl M ) . .It Fl -fast-read Stop after all non-wildcard extraction targets have been found in the archive. .It Fl G .It Fl -incremental Create/list/extract old GNU-format incremental backup. .It Fl g Ar file .It Fl -listed-incremental Ar file Create/list/extract new GNU-format incremental backup. .It Fl h .It Fl -dereference Don't write symlinks as symlinks; write the data of the files they name. .It Fl i .It Fl -ignore-zeros Ignore blocks of zeroes in archive (usually means End-Of-File). .It Fl -ignore-failed-read Don't exit with non-zero status on unreadable files. .It Fl k .It Fl -keep-old-files Keep files which already exist on disk; don't overwrite them from the archive. .It Fl K Ar file .It Fl -starting-file Ar file Begin at .Ar file in the archive. .It Fl l .It Fl -one-file-system Stay in local filesystem when creating an archive (do not cross mount points). .It Fl L Ar number .It Fl -tape-length Ar number Change tapes after writing N*1024 bytes. .It Fl m .It Fl -modification-time Don't extract file modified time. .It Fl M .It Fl -multi-volume Create/list/extract multi-volume archive. .It Fl N Ar date .It Fl -after-date Ar date .It Fl -newer Ar date Only store files newer than .Ar date . .It Fl o .It Fl -old-archive .It Fl -portability Write a V7 format archive, rather than POSIX format. .It Fl O .It Fl -to-stdout Extract files to standard output. .It Fl p .It Fl -same-permissions .It Fl -preserve-permissions Extract all protection information. .It Fl -preserve Has the effect of .Fl p s. .It Fl P .It Fl -absolute-paths Don't strip leading `/'s from file names. .It Fl R .It Fl -record-number Show record number within archive with each message. .It Fl -remove-files Remove files after adding them to the archive. .It Fl s .It Fl -same-order .It Fl -preserve-order List of names to extract is sorted to match archive. .It Fl S .It Fl -sparse Handle "sparse" files efficiently. .It Fl T Ar file .It Fl -files-from Ar file Get names of files to extract or create from .Ar file , one per line. .It Fl -null Modifies behavior of .Fl T to expect null-terminated names; disables .Fl C. .It Fl -totals Prints total bytes written with .Fl -create . .It Fl v .It Fl -verbose Lists files written to archive with .Fl -create or extracted with .Fl -extract ; lists file protection information along with file names with .Fl -list . .It Fl V Ar volume-name .It Fl -label Ar volume-name Create archive with the given .Ar volume-name . .It Fl -version Print tar program version number. .It Fl w .It Fl -interactive .It Fl -confirmation Ask for confirmation for every action. .It Fl W .It Fl -verify Attempt to verify the archive after writing it. .It Fl -exclude Ar pattern Exclude files matching the .Ar pattern (don't extract them, don't add them, don't list them). .It Fl X Ar file .It Fl -exclude-from Ar file Exclude files listed in .Ar file . .It Fl Z .It Fl -compress .It Fl -uncompress Filter the archive through .Xr compress 1 . .It Fl z .It Fl -gzip .It Fl -gunzip Filter the archive through .Xr gzip 1 . .It Fl -use-compress-program Ar program Filter the archive through .Ar program (which must accept .Fl d to mean ``decompress''). .It Fl -block-compress Block the output of compression program for tapes or floppies (otherwise writes will be of odd length, which device drivers may reject). .It Fl [0-7][lmh] Specify tape drive and density. .It Fl -norecurse Don't recurse into subdirectories when creating. .It Fl -unlink Unlink files before creating them. .El .Sh EXAMPLES To create an archive on tape drive .Pa /dev/rst0 with a block size of 20 blocks, containing files named "bert" and "ernie", you can enter .Dl tar cfb /dev/rst0 20 bert ernie or .Dl tar --create --file /dev/rst0 --block-size 20 bert ernie Note that the .Fl f and .Fl b flags both require arguments, which they take from the command line in the order they were listed in the command word. .Pp Because .Pa /dev/rst0 is the default device, and 20 is the default block size, the above example could have simply been .Dl tar c bert ernie .Pp To extract all the C sources and headers from an archive named "backup.tar", type .Dl tar xf backup.tar "*.[ch]" Note that the pattern must be quoted to prevent the shell from attempting to expand it according the files in the current working directory (the shell does not have access to the list of files in the archive, of course). .Pp To copy a file hierarchy while preserving metadata, type .Dl tar cf - -C srcdir ". |" tar xpf "-C destdir" .Pp To create a compressed archive on diskette, using gzip, use a command-line like .Dl tar --block-compress -z -c -v -f /dev/rfd1a -b 36 tar/ Note that you cannot mix bundled flags and --style flags; you can use single-letter flags in the manner above, rather than having to type .Dl tar --block-compress --gzip --verbose --file /dev/rfd1a --block-size 20 tar/ .Pp The above-created diskette can be listed with .Dl tar tvfbz /dev/rfd1a 36 .Pp To join two tar archives into a single archive, use .Dl tar Af archive1.tar archive2.tar which will add the files contained in archive2.tar onto the end of archive1.tar (note that this can't be done by simply typing .Dl cat archive2.tar >> archive1.tar because of the end-of-file block at the end of a tar archive). .Sh ENVIRONMENT The .Nm program examines the following environment variables: .Bl -tag -width "POSIXLY-CORRECT" .It Ev POSIXLY-CORRECT Normally, .Nm will process flag arguments that appear in the file list. If set in the environment, this flag causes .Nm to consider the first non-flag argument to terminate flag processing, as per the POSIX specification. .It Ev SHELL In interactive mode, a permissible response to the prompt is to request to spawn a subshell, which will be "/bin/sh" unless the .Ev SHELL variable is set. .It Ev TAPE Changes the default tape drive (which is still overridden by the .Fl f flag). .El .Sh FILES .Bl -tag -width "/dev/rst0" .It Pa /dev/rst0 The default tape drive. .El .\" This next request is for sections 1, 6, 7 & 8 only .\" (command return values (to shell) and fprintf/stderr type diagnostics) .\" .Sh DIAGNOSTICS .Sh SEE ALSO .Xr compress 1 , .Xr gzip 1 , .Xr pax 1 , .Xr rmt 8 .\" .Sh STANDARDS .Sh HISTORY The tar format has a rich history, dating back to Sixth Edition UNIX. The current implementation of tar is the GNU implementation, which originated as the public-domain tar written by John Gilmore. .Sh AUTHORS A cast of thousands, including [as listed in the ChangeLog file in the source] John Gilmore (author of original public domain version), Jay Fenlason (first GNU author), Joy Kendall, Jim Kingdon, David J. MacKenzie, Michael I Bushnell, Noah Friedman, and innumerable others who have contributed fixes and additions. .Sh BUGS The .Fl C feature does not work like historical tar programs, and is probably untrustworthy. .Pp The .Fl A command should work to join an arbitrary number of tar archives together, but it does not; attempting to do so leaves the end-of-archive blocks in place for the second and subsequent archives.