NAME

pax − portable archive exchange

SYNOPSIS

pax [−cimopuvy] [−f archive] [−s replstr] [−t device] [pattern...]

pax −r [−cimnopuvy] [−f archive] [−s replstr] [−t device]
[pattern...]

pax −w [−adimuvy] [−b blocking] [−f archive] [−s replstr]
[−t device] [−x format] [pathname...]

pax −rw [−ilmopuvy] [−s replstr] [pathname...] directory

DESCRIPTION

The pax utility reads and writes archive files which conform to the “Archive/Interchange File Format” specified in IEEE Std. 1003.1-1988. The pax utility can also read, but not write, a number of other file formats in addition to those specified in the “Archive/Interchange File Format” description.  Support for these traditional file formats, such as V7 tar and System V binary cpio format archives, is provided for backward compatibility and to maximize portability. 

Combinations of the −r and −w command line arguments specify whether pax will read, write, or list the contents of the specified archive, or move the specified files to another directory. 

The command line arguments are:

−w This argument writes the files and directories specified by pathname operands to the standard output together with the path name and status information prescribed by the archive format used.  A directory pathname operand refers to the files and (recursively) subdirectories of that directory.  If no pathname operands are given, then the standard input is read to get a list of path names to copy, one path name per line.  In this case, only those path names appearing on the standard input are copied. 

−r The pax utility reads an archive file from the standard input.  Only files with names that match any of the pattern operands are selected for extraction.  The selected files are conditionally created and copied relative to the current directory tree, subject to the options described below.  By default, the owner and group of selected files will be that of the invoking process, and the permissions and modification times will be the same as those in the archive. 

The supported archive formats are automatically detected on input.  The default output format is ustar, but that may be overridden by the −x format option described below. 

−rw The pax utility reads the files and directories named in the pathname operands and copies them to the destination directory. A directory pathname operand refers to the files and (recursively) subdirectories of that directory.  If no pathname operands are given, the standard input is read to get a list of path names to copy, one path name per line.  In this case, only those path names appearing on the standard input are copied.
The directory named by the directory operand must exist and it must have the proper permissions before the copy can occur. 

If neither the −r or −w options are given, pax will list the contents of the specified archive.  In this mode, pax lists normal files one per line, showing link path names as:

pathname == linkname

If the −v option is specified, then pax lists normal path names in the same format used by the ls utility with the −l option.  Links are shown as:

<ls -l listing> == linkname

The pax utility is capable of reading and writing archives that span multiple physical volumes.  Upon detecting an end of medium on an archive that is not yet completed, pax will prompt the user for the next volume of the archive and will allow the user to specify the location of the next volume. 

Options

The following options are available:

−a The files specified by pathname are appended to the specified archive. 

−b blocking Block the output at blocking bytes per write to the archive file.  A k suffix multiplies blocking by 1024, a b suffix multiplies blocking by 512, and an m suffix multiplies blocking by 1048576 (1 megabyte).  If not specified, blocking is automatically determined on input and is ignored for −rw. 

−c Complement the match sense of the pattern operands. 

−d Intermediate directories not explicitly listed in the archive are not created.  This option is ignored unless the −r option is specified. 

−f archive The archive option specifies the path name of the input or output archive, overriding the default of standard input for −r or standard output for −w. 

−i Interactively rename files.  Substitutions specified by −s options (described below) are performed before requesting the new file name from the user.  A file is skipped if an empty line is entered, and pax exits with an exit status of 0 if EOF is encountered. 

−l Files are linked rather than copied when possible. 

−m File modification times are not retained. 

−n When −r is specified, but −w is not, the pattern arguments are treated as ordinary file names.  Only the first occurrence of each of these files in the input archive is read.  The pax utility exits with a zero exit status after all files in the list have been read.  If one or more files in the list is not found, pax writes a diagnostic to standard error for each of the files and exits with a non-zero exit status.  The file names are compared before any of the −i, −s, or −y options are applied. 

−o Restore file ownership as specified in the archive.  The invoking process must have appropriate privileges to accomplish this. 

−p Preserve the access time of the input files after they have been copied. 

−s replstr Filenames are modified according to the substitution expression using the syntax of ed(1) as shown:

−s /old/new/[gp]

Any non-null character may be used as a delimiter (a / is used in this example).  Multiple −s expressions may be specified; the expressions are applied in the order specified terminating with the first successful substitution.  The optional trailing p causes successful mappings to be listed on standard error.  The optional trailing g causes the old expression to be replaced each time it occurs in the source string.  Files that substitute to an empty string are ignored both on input and output. 

−t device The device option argument is an implementation-defined identifier that names the input or output archive device, overriding the default of standard input for −r and standard output for −w. 

−u Copy each file only if it is newer than a pre-existing file with the same name.  This implies −a. 

−v List file names as they are encountered.  Produces a verbose table of contents listing on the standard output when both −r and −w are omitted; otherwise the file names are printed to standard error as they are encountered in the archive. 

−x format Specifies the output archive format. The input format, which must be one of the following, is automatically determined when the −r option is used.  The supported formats are:

cpio The extended CPIO interchange format specified in “Extended CPIO Format” in IEEE Std. 1003.1-1988.

ustar The extended TAR interchange format specified in “Extended TAR Format” in IEEE Std. 1003.1-1988. This is the default archive format.

−y Interactively prompt for the disposition of each file.  Substitutions specified by −s options (described above) are performed before prompting the user for disposition.  EOF or an input line starting with the character q cause pax to exit.  Otherwise, an input line starting with anything other than y causes the file to be ignored.  This option cannot be used in conjunction with the −i option. 

Only the last of multiple −f or −t options take effect. 

When writing to an archive, the standard input is used as a list of path names if no pathname operands are specified.  The format is one path name per line.  Otherwise, the standard input is the archive file. 

The user ID and group ID of the process, together with the appropriate privileges, affect the ability of pax to restore ownership and permissions attributes of the archived files. 

The options −a, −c, −d, −i, −l, −p, −t, −u, and −y are provided for functional compatibility with the historical cpio and tar utilities.  The option defaults were chosen based on the most common usage of these options; therefore, some of the options have meanings different than those of the historical commands. 

Operands

The following operands are available:

directory The destination directory path name for copies when both the −r and −w options are specified.  The directory must exist and be writable before the copy or error results. 

pathname A file whose contents are used instead of the files named on the standard input.  When a directory is named, all of its files and (recursively) subdirectories are copied as well. 

pattern A pattern is given in the standard shell pattern matching notation.  The default if no pattern is  specified is *, which selects all files. 

EXAMPLES

The following command:

pax −w −f /dev/rmt0 . 

copies the contents of the current directory to tape drive 0. 

The commands

mkdir newdir
cd olddir
pax -rw . ../newdir

copies the contents of olddir to newdir.

The command

pax −r −s ’,//*usr//*,,’ -f pax.out

reads the archive pax.out with all files rooted in /usr in the archive extracted relative to the current directory. 

FILES

/dev/tty Used to prompt the user for information when the −i or −y options are specified

SEE ALSO

cpio(1), find(1), tar(1) in the User’s/System Administrator’s Reference Manual.
cpio(5), tar(5).

DIAGNOSTICS

pax will terminate immediately, without processing any additional files on the command line or in the archive. 

EXIT CODES

pax will exit with one of the following values:

0All files in the archive were processed successfully. 

>0pax aborted due to errors encountered during operation. 

BUGS

Special permissions may be required to copy or extract special files. 

Device, user ID, and group ID numbers larger than 65535 cause additional header records to be output.  These records are ignored by some historical versions of cpio(1) and tar(1).

The archive formats described in “Archive/Interchange File Format” have certain restrictions that have been carried over from historical usage.  For example, there are restrictions on the length of path names stored in the archive. 

When getting an ls −l style listing on tar format archives, link counts are listed as zero since the ustar archive format does not keep link count information. 

SOURCE

Copyright © 1989 Mark H. Colburn. 
All rights reserved.

This version of the pax utility is derived from software developed by Mark H. Colburn and sponsored by The USENIX Association. 

\*U  —  Version 1.0