1.\" $NetBSD: tar.1,v 1.26 2007/12/02 21:14:49 wiz Exp $ 2.\" 3.\" Copyright (c) 1996 SigmaSoft, Th. Lockert 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25.\" 26.\" OpenBSD: tar.1,v 1.28 2000/11/09 23:58:56 aaron Exp 27.\" 28.Dd May 4, 2007 29.Dt TAR 1 30.Os 31.Sh NAME 32.Nm tar 33.Nd tape archiver 34.Sh SYNOPSIS 35.Nm tar 36.Sm off 37.Oo \&- Oc {crtux} Op Fl 014578befHhjklmOoPpqSvwXZz 38.Sm on 39.Op Ar archive 40.Op Ar blocksize 41.\" XXX how to do this right? 42.Op Fl C Ar directory 43.Op Fl s Ar replstr 44.Op Fl T Ar file 45.Op Ar file ... 46.Sh DESCRIPTION 47The 48.Nm 49command creates, adds files to, or extracts files from an 50archive file in 51.Dq tar 52format. 53A tar archive is often stored on a magnetic tape, but can be 54stored equally well on a floppy, CD-ROM, or in a regular disk file. 55.Pp 56One of the following flags must be present: 57.Bl -tag -width Ar 58.It Fl c , -create 59Create new archive, or overwrite an existing archive, 60adding the specified files to it. 61.It Fl r , -append 62Append the named new files to existing archive. 63Note that this will only work on media on which an end-of-file mark 64can be overwritten. 65.It Fl t , -list 66List contents of archive. 67If any files are named on the 68command line, only those files will be listed. 69.It Fl u , -update 70Alias for 71.Fl r . 72.It Fl x , -extract , -get 73Extract files from archive. 74If any files are named on the 75command line, only those files will be extracted from the 76archive. 77If more than one copy of a file exists in the 78archive, later copies will overwrite earlier copies during 79extraction. 80The file mode and modification time are preserved 81if possible. 82The file mode is subject to modification by the 83.Xr umask 2 . 84.El 85.Pp 86In addition to the flags mentioned above, any of the following 87flags may be used: 88.Bl -tag -width Ar 89.It Fl b Ar "blocking factor" , Fl -block-size Ar "blocking factor" 90Set blocking factor to use for the archive. 91.Nm 92uses 512 byte blocks. 93The default is 20, the maximum is 126. 94Archives with a blocking factor larger 63 violate the 95.Tn POSIX 96standard and will not be portable to all systems. 97.It Fl e 98Stop after first error. 99.It Fl f Ar archive , Fl -file Ar archive 100Filename where the archive is stored. 101Defaults to 102.Pa /dev/rst0 . 103If the archive is of the form: 104.Ar [[user@]host:]file 105then the archive will be processed using 106.Xr rmt 8 . 107.It Fl h , -dereference 108Follow symbolic links as if they were normal files 109or directories. 110.It Fl j, -bzip2, -bunzip2 111Use 112.Xr bzip2 1 113for compression of the archive. 114This option is a GNU extension. 115.It Fl k , -keep-old-files 116Keep existing files; don't overwrite them from archive. 117.It Fl l , -one-file-system 118Do not descend across mount points. 119.\" should be '-X' 120.It Fl m , -modification-time 121Do not preserve modification time. 122.It Fl O 123When creating and appending to an archive, write old-style (non-POSIX) archives. 124When extracting from an archive, extract to standard output. 125.It Fl o , -portability , -old-archive 126Don't write directory information that the older (V7) style 127.Nm 128is unable to decode. 129This implies the 130.Fl O 131flag. 132.It Fl p , -preserve-permissions , -preserve 133Preserve user and group ID as well as file mode regardless of 134the current 135.Xr umask 2 . 136The setuid and setgid bits are only preserved if the user is 137the superuser. 138Only meaningful in conjunction with the 139.Fl x 140flag. 141.It Fl q , -fast-read 142Select the first archive member that matches each 143.Ar pattern 144operand. 145No more than one archive member is matched for each 146.Ar pattern . 147When members of type directory are matched, the file hierarchy rooted at that 148directory is also matched. 149.It Fl S , -sparse 150This flag has no effect as 151.Nm 152always generates sparse files. 153.It Fl s Ar replstr 154Modify the file or archive member names specified by the 155.Ar pattern 156or 157.Ar file 158operands according to the substitution expression 159.Ar replstr , 160using the syntax of the 161.Xr ed 1 162utility regular expressions. 163The format of these regular expressions are: 164.Dl /old/new/[gps] 165As in 166.Xr ed 1 , 167.Cm old 168is a basic regular expression and 169.Cm new 170can contain an ampersand (\*[Am]), \\n (where n is a digit) back-references, 171or subexpression matching. 172The 173.Cm old 174string may also contain 175.Aq Dv newline 176characters. 177Any non-null character can be used as a delimiter (/ is shown here). 178Multiple 179.Fl s 180expressions can be specified. 181The expressions are applied in the order they are specified on the 182command line, terminating with the first successful substitution. 183The optional trailing 184.Cm g 185continues to apply the substitution expression to the pathname substring 186which starts with the first character following the end of the last successful 187substitution. 188The first unsuccessful substitution stops the operation of the 189.Cm g 190option. 191The optional trailing 192.Cm p 193will cause the final result of a successful substitution to be written to 194.Dv standard error 195in the following format: 196.Dl \*[Lt]original pathname\*[Gt] \*[Gt]\*[Gt] \*[Lt]new pathname\*[Gt] 197File or archive member names that substitute to the empty string 198are not selected and will be skipped. 199The substitutions are applied by default to the destination hard and symbolic 200links. 201The optional trailing 202.Cm s 203prevents the substitutions from being performed on symbolic link destinations. 204.It Fl v 205Verbose operation mode. 206.It Fl w , -interactive , -confirmation 207Interactively rename files. 208This option causes 209.Nm 210to prompt the user for the filename to use when storing or 211extracting files in an archive. 212.It Fl z , -gzip , -gunzip 213Compress archive using gzip. 214.It Fl B , -read-full-blocks 215Reassemble small reads into full blocks (For reading from 4.2BSD pipes). 216.It Fl C Ar directory , Fl -directory Ar directory 217This is a positional argument which sets the working directory for the 218following files. 219When extracting, files will be extracted into 220the specified directory; when creating, the specified files will be matched 221from the directory. 222This argument and its parameter may also appear in a file list specified by 223.Fl T . 224.It Fl H 225Only follow symlinks given on command line. 226.Pp 227Note SysVr3/i386 picked up ISC/SCO UNIX compatabilty which implemented 228.Dq Fl F Ar file 229which was defined as obtaining a list of command line switches and files 230on which to operate from the specified file, 231but SunOS-5 uses 232.Dq Fl I Ar file 233because they use 234.Sq Fl F 235to mean something else. 236We might someday provide SunOS-5 compatability 237but it makes little sense to confuse things with ISC/SCO compatability. 238.\".It Fl L 239.\"Do not follow any symlinks (do the opposite of 240.\".Fl h ). 241.It Fl P , -absolute-paths 242Do not strip leading slashes 243.Pq Sq / 244from pathnames. 245The default is to strip leading slashes. 246.It Fl T Ar file , Fl -files-from Ar file 247Read the names of files to archive or extract from the given file, one 248per line. 249A line may also specify the positional argument 250.Dq Fl C Ar directory . 251.It Fl X Ar file , Fl -exclude-from Ar file 252Exclude files listed in the given file. 253.\" exclude should be '-E' and '-X' should be one-file-system 254.Pp 255Note that it would be more standard to use this option to mean ``do not 256cross filesystem mount points.'' 257.It Fl Z , -compress , -uncompress 258Compress archive using compress. 259.It Fl -strict 260Do not enable GNU tar extensions such as long filenames and long link names. 261.It Fl -atime-preserve 262Preserve file access times. 263.It Fl -chroot 264.Fn chroot 265to the current directory before extracting files. 266Use with 267.Fl x 268and 269.Fl h 270to make absolute symlinks relative to the current directory. 271.It Fl -unlink 272Ignored, only accepted for compatibility with other 273.Nm 274implementations. 275.Nm 276always unlinks files before creating them. 277.It Fl -use-compress-program Ar program 278Use the named program as the program to decompress the input. 279.It Fl -force-local 280Do not interpret filenames that contain a 281.Sq \&: 282as remote files. 283.It Fl -insecure 284Normally 285.Nm 286ignores filenames that contain 287.Dq .. 288as a path component. 289With this option, files that contain 290.Dq .. 291can be processed. 292.It Fl -no-recursion 293Cause files of type directory being copied or archived, or archive members of 294type directory being extracted, to match only the directory file or archive 295member and not the file hierarchy rooted at the directory. 296.El 297.Pp 298The options 299.Op Fl 014578 300can be used to select one of the compiled-in backup devices, 301.Pa /dev/rstN . 302.Sh FILES 303.Bl -tag -width "/dev/rst0" 304.It Pa /dev/rst0 305default archive name 306.El 307.Sh DIAGNOSTICS 308.Nm 309will exit with one of the following values: 310.Bl -tag -width 2n 311.It 0 312All files were processed successfully. 313.It 1 314An error occurred. 315.El 316.Pp 317Whenever 318.Nm 319cannot create a file or a link when extracting an archive or cannot 320find a file while writing an archive, or cannot preserve the user 321ID, group ID, file mode, or access and modification times when the 322.Fl p 323option is specified, a diagnostic message is written to standard 324error and a non-zero exit value will be returned, but processing 325will continue. 326In the case where 327.Nm 328cannot create a link to a file, 329.Nm 330will not create a second copy of the file. 331.Pp 332If the extraction of a file from an archive is prematurely terminated 333by a signal or error, 334.Nm 335may have only partially extracted the file the user wanted. 336Additionally, the file modes of extracted files and directories may 337have incorrect file bits, and the modification and access times may 338be wrong. 339.Pp 340If the creation of an archive is prematurely terminated by a signal 341or error, 342.Nm 343may have only partially created the archive which may violate the 344specific archive format specification. 345.Sh SEE ALSO 346.Xr cpio 1 , 347.Xr pax 1 348.Sh HISTORY 349A 350.Nm 351command first appeared in 352.At v7 . 353.Sh AUTHORS 354Keith Muller at the University of California, San Diego. 355