Manual Pages  — PAX

The pattern operand is used to select one or more pathnames of archive members. Archive members are selected using the pattern matching notation described by fnmatch(3). When the pattern operand is not supplied, all members of the archive will be selected. When a pattern matches a directory, the entire file hierarchy rooted at that directory will be selected. When a pattern operand does not select at least one archive member, pax will write these pattern operands in a diagnostic message to standard error and then exit with a non-zero exit status.

The file operand specifies the pathname of a file to be copied or archived. When a file operand does not select at least one archive member, pax will write these file operand pathnames in a diagnostic message to standard error and then exit with a non-zero exit status.

File flags set by chflags(1) are not understood by pax, however tar(1) and dump(8) will preserve these.

-s replstr
	Modify the file or archive member names specified by the pattern or file operands according to the substitution expression replstr, using the syntax of the ed(1) utility regular expressions. The format of these regular expressions are:     /old/new/[gp] As in ed(1), old is a basic regular expression and new can contain an ampersand (&),  (where n is a digit) back-references, or subexpression matching. The old string may also contain <newline> characters. Any non-null character can be used as a delimiter (/ is shown here). Multiple -s expressions can be specified. The expressions are applied in the order they are specified on the command line, terminating with the first successful substitution. The optional trailing g continues to apply the substitution expression to the pathname substring which starts with the first character following the end of the last successful substitution. The first unsuccessful substitution stops the operation of the g option. The optional trailing p will cause the final result of a successful substitution to be written to standard error in the following format:     <original pathname> >> <new pathname> File or archive member names that substitute to the empty string are not selected and will be skipped.
-t
	Reset the access times of any file or directory read or accessed by pax to be the same as they were before being read or accessed by pax.
-u
	Ignore files that are older (having a less recent file modification time) than a pre-existing file or archive member with the same name. During read, an archive member with the same name as a file in the file system will be extracted if the archive member is newer than the file. During write, a file system member with the same name as an archive member will be written to the archive if it is newer than the archive member. During copy, the file in the destination hierarchy is replaced by the file in the source hierarchy or by a link to the file in the source hierarchy if the file in the source hierarchy is newer.
-v
	During a list operation, produce a verbose table of contents using the format of the ls(1) utility with the -l option. For pathnames representing a hard link to a previous member of the archive, the output has the format:     <ls -l listing> == <link name> For pathnames representing a symbolic link, the output has the format:     <ls -l listing> => <link name> Where <ls -l listing> is the output format specified by the ls(1) utility when used with the -l option. Otherwise for all the other operational modes ( read, write, and copy), pathnames are written and flushed to standard error without a trailing <newline> as soon as processing begins on that file or archive member. The trailing <newline>, is not buffered, and is written only after the file has been read or written.
-x format
	Specify the output archive format, with the default format being ustar. The pax utility currently supports the following formats:

cpio	The extended cpio interchange format specified in the IEEE Std 1003.2 ("POSIX.2") standard. The default blocksize for this format is 5120 bytes. Inode and device information about a file (used for detecting file hard links by this format) which may be truncated by this format is detected by pax and is repaired.
bcpio	The old binary cpio format. The default blocksize for this format is 5120 bytes. This format is not very portable and should not be used when other formats are available. Inode and device information about a file (used for detecting file hard links by this format) which may be truncated by this format is detected by pax and is repaired.
sv4cpio
	The System V release 4 cpio. The default blocksize for this format is 5120 bytes. Inode and device information about a file (used for detecting file hard links by this format) which may be truncated by this format is detected by pax and is repaired.
sv4crc	The System V release 4 cpio with file crc checksums. The default blocksize for this format is 5120 bytes. Inode and device information about a file (used for detecting file hard links by this format) which may be truncated by this format is detected by pax and is repaired.
tar	The old BSD tar format as found in BSD 4.3 . The default blocksize for this format is 10240 bytes. Pathnames stored by this format must be 100 characters or less in length. Only regular files, hard links, soft links, and directories will be archived (other file system types are not supported). For backwards compatibility with even older tar formats, a -o option can be used when writing an archive to omit the storage of directories. This option takes the form:     -o write_opt=nodir
ustar	The extended tar interchange format specified in the IEEE Std 1003.2 ("POSIX.2") standard. The default blocksize for this format is 10240 bytes. Pathnames stored by this format must be 255 characters or less in length. The directory part may be at most 155 characters and each path component must be less than 100 characters.

The pax utility will detect and report any file that it is unable to store or extract as the result of any specific archive format restrictions. The individual archive formats may impose additional restrictions on use. Typical archive format restrictions include (but are not limited to): file pathname length, file size, link pathname length and the type of the file.

-z
	Use gzip(1) to compress (decompress) the archive while writing (reading). Incompatible with -a.
-B bytes
	Limit the number of bytes written to a single archive volume to bytes. The bytes limit can end with m, k, or b to specify multiplication by 1048576 (1M), 1024 (1K) or 512, respectively. A pair of bytes limits can be separated by x to indicate a product. Warning: Only use this option when writing an archive to a device which supports an end of file read condition based on last (or largest) write offset (such as a regular file or a tape drive). The use of this option with a floppy or hard disk is not recommended.
-D
	This option is the same as the -u option, except that the file inode change time is checked instead of the file modification time. The file inode change time can be used to select files whose inode information (e.g.amp; uid, gid, etc.) is newer than a copy of the file in the destination directory.
-E limit
	Limit the number of consecutive read faults while trying to read a flawed archives to limit. With a positive limit, pax will attempt to recover from an archive read error and will continue processing starting with the next file stored in the archive. A limit of 0 will cause pax to stop operation after the first read error is detected on an archive volume. A limit of NONE will cause pax to attempt to recover from read errors forever. The default limit is a small positive number of retries. Warning: Using this option with NONE should be used with extreme caution as pax may get stuck in an infinite loop on a very badly flawed archive.
-G group
	Select a file based on its group name, or when starting with a #, a numeric gid. A '\' can be used to escape the #. Multiple -G options may be supplied and checking stops with the first match.
-H
	Follow only command line symbolic links while performing a physical file system traversal.
-L
	Follow all symbolic links to perform a logical file system traversal.
-O
	Force the archive to be one volume. If a volume ends prematurely, pax will not prompt for a new volume. This option can be useful for automated tasks where error recovery cannot be performed by a human.
-P
	Do not follow symbolic links, perform a physical file system traversal. This is the default mode.
-T [from_date][,to_date][/[c][m]]
	Allow files to be selected based on a file modification or inode change time falling within a specified time range of from_date to to_date (the dates are inclusive). If only a from_date is supplied, all files with a modification or inode change time equal to or younger are selected. If only a to_date is supplied, all files with a modification or inode change time equal to or older will be selected. When the from_date is equal to the to_date, only files with a modification or inode change time of exactly that time will be selected. When pax is in the write or copy mode, the optional trailing field [c][m] can be used to determine which file time (inode change, file modification or both) are used in the comparison. If neither is specified, the default is to use file modification time only. The m specifies the comparison of file modification time (the time when the file was last written). The c specifies the comparison of inode change time (the time when the file inode was last changed; e.g.amp; a change of owner, group, mode, etc). When c and m are both specified, then the modification and inode change times are both compared. The inode change time comparison is useful in selecting files whose attributes were recently changed or selecting files which were recently created and had their modification time reset to an older time (as what happens when a file is extracted from an archive and the modification time is preserved). Time comparisons using both file times is useful when pax is used to create a time based incremental archive (only files that were changed during a specified time range will be archived). A time range is made up of six different fields and each field must contain two digits. The format is:     [yy[mm[dd[hh]]]]mm[.ss] Where yy is the last two digits of the year, the first mm is the month (from 01 to 12), dd is the day of the month (from 01 to 31), hh is the hour of the day (from 00 to 23), the second mm is the minute (from 00 to 59), and ss is the seconds (from 00 to 59). The minute field mm is required, while the other fields are optional and must be added in the following order:     hh, dd, mm, yy. The ss field may be added independently of the other fields. Time ranges are relative to the current time, so     -T 1234/cm would select all files with a modification or inode change time of 12:34 PM today or later. Multiple -T time range can be supplied and checking stops with the first match.
-U user
	Select a file based on its user name, or when starting with a #, a numeric uid. A '\' can be used to escape the #. Multiple -U options may be supplied and checking stops with the first match.
-X
	When traversing the file hierarchy specified by a pathname, do not descend into directories that have a different device ID. See the st_dev field as described in stat(2) for more information about device ID's.
-Y
	This option is the same as the -D option, except that the inode change time is checked using the pathname created after all the file name modifications have completed.
-Z
	This option is the same as the -u option, except that the modification time is checked using the pathname created after all the file name modifications have completed.

The options that operate on the names of files or archive members -( -c, -i, -n, -s, -u, -v, -D, -G, -T, -U, -Y, and -Z) interact as follows.

When extracting files during a read operation, archive members are 'selected', based only on the user specified pattern operands as modified by the -c, -n, -u, -D, -G, -T, -U options. Then any -s and -i options will modify in that order, the names of these selected files. Then the -Y and -Z options will be applied based on the final pathname. Finally the -v option will write the names resulting from these modifications.

When archiving files during a write operation, or copying files during a copy operation, archive members are 'selected', based only on the user specified pathnames as modified by the -n, -u, -D, -G, -T, and -U options (the -D option only applies during a copy operation). Then any -s and -i options will modify in that order, the names of these selected files. Then during a copy operation the -Y and the -Z options will be applied based on the final pathname. Finally the -v option will write the names resulting from these modifications.

When one or both of the -u or -D options are specified along with the -n option, a file is not considered selected unless it is newer than the file to which it is compared.

File flags set by chflags(1) are not preserved by pax. The BUGS section of chflags(1) has a list of utilities that are unaware of flags.