Like other POSIX programs, pax is unable to access tape drives. It can only be used to read and write
archive files on disk drives. Pax reads and writes archive files which conform to the Archive/Interchange File
Format specified in IEEE Std. 1003.1-1988. Pax 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
If neither the -r or -w options are given, then pax will list the contents of the specified archive. In this mode, pax lists normal files one per line, hard link pathnames as
pathname == linkname
and symbolic link pathnames (if supported by the implementation) as
pathname -> linkname
where pathname is the name of the file being extracted, and linkname is the
name of a file which appeared earlier in the archive.
If the -v option is specified, then pax list normal path names in the same format used by the ls utility with the -l option. Hard links are shown as
<ls -l listing> == linkname
and symbolic links (if supported) are shown as
<ls -l listing> -> linkname
Upon detecting an end of medium on an archive which 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.
When writing to an archive, the standard input is used as a list of pathnames
if no pathname operands are specified. The format is one pathname per line.
Otherwise, the standard input is the archive file, which is formatted according
to one of the specifications in Archive/Interchange File format in IEEE Std.
1003.1-1988, or some other implementation-defined format.
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. (See
format-reading utility in Archive/Interchange File Format in IEEE Std.
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.
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