1.\" $NetBSD: tar.1,v 1.18 2004/10/17 18:49:55 dsl 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 September 27, 2004 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 befhjklmopqvwzHOPSXZ014578 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 T Ar file 44.Op Fl s Ar replstr 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 cross filesystems. 119.It Fl m , -modification-time 120Do not preserve modification time. 121.It Fl O 122When creating and appending to an archive, write old-style (non-POSIX) archives. 123When extracting from an archive, extract to standard output. 124.It Fl o , -portability , -old-archive 125Don't write directory information that the older (V7) style 126.Nm 127is unable to decode. 128This implies the 129.Fl O 130flag. 131.It Fl p , -preserve-permissions , -preserve 132Preserve user and group ID as well as file mode regardless of 133the current 134.Xr umask 2 . 135The setuid and setgid bits are only preserved if the user is 136the superuser. 137Only meaningful in conjunction with the 138.Fl x 139flag. 140.It Fl q , -fast-read 141Select the first archive member that matches each 142.Ar pattern 143operand. 144No more than one archive member is matched for each 145.Ar pattern . 146When members of type directory are matched, the file hierarchy rooted at that 147directory is also matched. 148.It Fl S , -sparse 149This flag has no effect as 150.Nm 151always generates sparse files. 152.It Fl s Ar replstr 153Modify the file or archive member names specified by the 154.Ar pattern 155or 156.Ar file 157operands according to the substitution expression 158.Ar replstr , 159using the syntax of the 160.Xr ed 1 161utility regular expressions. 162The format of these regular expressions are: 163.Dl /old/new/[gp] 164As in 165.Xr ed 1 , 166.Cm old 167is a basic regular expression and 168.Cm new 169can contain an ampersand (\*[Am]), \\n (where n is a digit) back-references, 170or subexpression matching. 171The 172.Cm old 173string may also contain 174.Aq Dv newline 175characters. 176Any non-null character can be used as a delimiter (/ is shown here). 177Multiple 178.Fl s 179expressions can be specified. 180The expressions are applied in the order they are specified on the 181command line, terminating with the first successful substitution. 182The optional trailing 183.Cm g 184continues to apply the substitution expression to the pathname substring 185which starts with the first character following the end of the last successful 186substitution. 187The first unsuccessful substitution stops the operation of the 188.Cm g 189option. 190The optional trailing 191.Cm p 192will cause the final result of a successful substitution to be written to 193.Dv standard error 194in the following format: 195.Dl \*[Lt]original pathname\*[Gt] \*[Gt]\*[Gt] \*[Lt]new pathname\*[Gt] 196File or archive member names that substitute to the empty string 197are not selected and will be skipped. 198.It Fl v 199Verbose operation mode. 200.It Fl w , -interactive , -confirmation 201Interactively rename files. 202This option causes 203.Nm 204to prompt the user for the filename to use when storing or 205extracting files in an archive. 206.It Fl z , -gzip , -gunzip 207Compress archive using gzip. 208.It Fl B , -read-full-blocks 209Reassemble small reads into full blocks (For reading from 4.2BSD pipes). 210.It Fl C Ar directory , Fl -directory Ar directory 211This is a positional argument which sets the working directory for the 212following files. 213When extracting, files will be extracted into 214the specified directory; when creating, the specified files will be matched 215from the directory. 216This argument and its parameter may also appear in a file list specified by 217.Fl T . 218.It Fl H 219Follow symlinks given on command line only. 220.It Fl P , -absolute-paths 221Do not strip leading slashes 222.Pq Sq / 223from pathnames. 224The default is to strip leading slashes. 225.It Fl T Ar file , Fl -files-from Ar file 226Read the names of files to archive or extract from the given file, one 227per line. 228A line may also specify the positional argument 229.Dq Fl C Ar directory . 230.It Fl X Ar file , Fl -exclude-from Ar file 231Exclude files listed in the given file. 232.It Fl Z , -compress , -uncompress 233Compress archive using compress. 234.It Fl -strict 235Do not enable GNU tar extensions such as long filenames and long link names. 236.It Fl -atime-preserve 237Preserve file access times. 238.It Fl -chroot 239.Fn chroot 240to the current directory before extracting files. 241Use with 242.Fl x 243and 244.Fl h 245to make absolute symlinks be relative to the current directory. 246.It Fl -unlink 247Ignored, only accepted for compatibility with other 248.Nm 249implementations. 250.Nm 251always unlinks files before creating them. 252.It Fl -use-compress-program Ar program 253Use the named program as the program to decompress the input. 254.It Fl -force-local 255Do not interpret filenames that contain a 256.Sq \&: 257as remote files. 258.It Fl -insecure 259Normally 260.Nm 261ignores filenames that contain 262.Sq .. 263as a path component. 264With this option, files that contain 265.Sq .. 266can be processed. 267.El 268.Pp 269The options 270.Op Fl 014578 271can be used to select one of the compiled-in backup devices, 272.Pa /dev/rstN . 273.Sh FILES 274.Bl -tag -width "/dev/rst0" 275.It Pa /dev/rst0 276default archive name 277.El 278.Sh DIAGNOSTICS 279.Nm 280will exit with one of the following values: 281.Bl -tag -width 2n 282.It 0 283All files were processed successfully. 284.It 1 285An error occurred. 286.El 287.Pp 288Whenever 289.Nm 290cannot create a file or a link when extracting an archive or cannot 291find a file while writing an archive, or cannot preserve the user 292ID, group ID, file mode, or access and modification times when the 293.Fl p 294option is specified, a diagnostic message is written to standard 295error and a non-zero exit value will be returned, but processing 296will continue. 297In the case where 298.Nm 299cannot create a link to a file, 300.Nm 301will not create a second copy of the file. 302.Pp 303If the extraction of a file from an archive is prematurely terminated 304by a signal or error, 305.Nm 306may have only partially extracted the file the user wanted. 307Additionally, the file modes of extracted files and directories may 308have incorrect file bits, and the modification and access times may 309be wrong. 310.Pp 311If the creation of an archive is prematurely terminated by a signal 312or error, 313.Nm 314may have only partially created the archive which may violate the 315specific archive format specification. 316.Sh SEE ALSO 317.Xr cpio 1 , 318.Xr pax 1 319.Sh HISTORY 320A 321.Nm 322command first appeared in 323.At v7 . 324.Sh AUTHORS 325Keith Muller at the University of California, San Diego. 326