PAX(1)			  BSD General Commands Manual			PAX(1)

NAME
     pax - read and write file archives and copy directory hierarchies

SYNOPSIS
     pax [-0cdOnvz] [-f archive] [-s replstr] ... [-U user] ... [-G group] ...
	 [-T [from_date] [,to_date]] ... [pattern ...]
     pax -r [-cdiknuvzDOYZ] [-f archive] [-o options] ... [-p string] ...
	 [-s replstr] ... [-E limit] [-U user] ... [-G group] ... [-T
	 [from_date] [,to_date]] ... [pattern ...]
     pax -w [-0dituvzHLOPX] [-b blocksize] [[-a] [-f archive]] [-x format]
	 [-s replstr] ... [-o options] ... [-U user] ... [-G group] ...
	 [-B bytes] [-T [from_date] [,to_date] [/[c][m]]] ... [file ...]
     pax -r -w [-0diklntuvDHLOPXYZ] [-p string] ... [-s replstr] ... [-U user]
	 ... [-G group] ... [-T [from_date] [,to_date] [/[c][m]]] ...
	 [file ...] directory

DESCRIPTION
     pax will read, write, and list the members of an archive file, and will
     copy directory hierarchies.  pax operation is independent of the specific
     archive format, and supports a wide variety of different archive formats.
     A list of supported archive formats can be found under the description of
     the -x option.

     The presence of the -r and the -w options specifies which of the follow-
     ing functional modes pax will operate under: list, read, write, and copy.

       List.  pax will write to standard output a table of contents of
	     the members of the archive file read from standard input, whose
	     pathnames match the specified patterns.  The table of contents
	     contains one filename per line and is written using single line
	     buffering.

     -r	     Read.  pax extracts the members of the archive file read from the
	     standard input, with pathnames matching the specified patterns.
	     The archive format and blocking is automatically determined on
	     input.  When an extracted file is a directory, the entire file
	     hierarchy rooted at that directory is extracted.  All extracted
	     files are created relative to the current file hierarchy.	The
	     setting of ownership, access and modification times, and file
	     mode of the extracted files are discussed in more detail under
	     the -p option.

     -w	     Write.  pax writes an archive containing the file operands to
	     standard output using the specified archive format.  When no file
	     operands are specified, a list of files to copy with one per line
	     is read from standard input.  When a file operand is also a
	     directory, the entire file hierarchy rooted at that directory
	     will be included.

     -r -w   Copy.  pax copies the file operands to the destination directory.
	     When no file operands are specified, a list of files to copy with
	     one per line is read from the standard input.  When a file
	     operand is also a directory the entire file hierarchy rooted at
	     that directory will be included.  The effect of the copy is as if
	     the copied files were written to an archive file and then subse-
	     quently extracted, except that there may be hard links between
	     the original and the copied files (see the -l option below).

	     Warning: The destination directory must not be one of the file
	     operands or a member of a file hierarchy rooted at one of the
	     file operands.  The result of a copy under these conditions is
	     unpredictable.

     While processing a damaged archive during a read or list operation, pax
     will attempt to recover from media defects and will search through the
     archive to locate and process the largest number of archive members pos-
     sible (see the -E option for more details on error handling).

     The directory operand specifies a destination directory pathname.	If the
     directory operand does not exist, or it is not writable by the user, or
     it is not of type directory, pax will exit with a non-zero exit status.

     The pattern operand is used to select one or more pathnames of archive
     members.  Archive members are selected using the pattern matching nota-
     tion 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 mem-
     ber, pax will write these file operand pathnames in a diagnostic message
     to standard error and then exit with a non-zero exit status.

     The options are as follows:

     -r	     Read an archive file from standard input and extract the speci-
	     fied files.  If any intermediate directories are needed in order
	     to extract an archive member, these directories will be created
	     as if mkdir(2) was called with the bitwise inclusive OR of
	     S_IRWXU, S_IRWXG, and S_IRWXO as the mode argument.  When the
	     selected archive format supports the specification of linked
	     files and these files cannot be linked while the archive is being
	     extracted, pax will write a diagnostic message to standard error
	     and exit with a non-zero exit status at the completion of opera-
	     tion.

     -w	     Write files to the standard output in the specified archive for-
	     mat.  When no file operands are specified, standard input is read
	     for a list of pathnames with one per line without any leading or
	     trailing .

     -a	     Append files to the end of an archive that was previously writ-
	     ten.  If an archive format is not specified with a -x option, the
	     format currently being used in the archive will be selected.  Any
	     attempt to append to an archive in a format different from the
	     format already used in the archive will cause pax to exit immedi-
	     ately with a non-zero exit status.	 The blocking size used in the
	     archive volume where writing starts will continue to be used for
	     the remainder of that archive volume.

	     Warning: Many storage devices are not able to support the opera-
	     tions necessary to perform an append operation.  Any attempt to
	     append to an archive stored on such a device may damage the
	     archive or have other unpredictable results.  Tape drives in par-
	     ticular are more likely to not support an append operation.  An
	     archive stored in a regular file system file or on a disk device
	     will usually support an append operation.

     -0	     Use the NUL ('\0') character as a pathname terminator, instead of
	     newline ('\n').  This applies only to the pathnames read from
	     standard input in the write and copy modes, and to the pathnames
	     written to standard output in list mode.  This option is expected
	     to be used in concert with the -print0 function in find(1) or the
	     -0 flag in xargs(1).

     -b blocksize
	     When writing an archive, block the output at a positive decimal
	     integer number of bytes per write to the archive file.  The
	     blocksize must be a multiple of 512 bytes with a maximum of 64512
	     bytes.  Archives larger than 32256 bytes violate the POSIX stan-
	     dard and will not be portable to all systems.  A blocksize can
	     end with 'k' or 'b' to specify multiplication by 1024 (1K) or
	     512, respectively.	 A pair of blocksizes can be separated by 'x'
	     to indicate a product.  A specific archive device may impose
	     additional restrictions on the size of blocking it will support.
	     When blocking is not specified, the default blocksize is depen-
	     dent on the specific archive format being used (see the -x
	     option).

     -c	     Match all file or archive members except those specified by the
	     pattern and file operands.

     -d	     Cause files of type directory being copied or archived, or
	     archive members of type directory being extracted, to match only
	     the directory file or archive member and not the file hierarchy
	     rooted at the directory.

     -f archive
	     Specify archive as the pathname of the input or output archive,
	     overriding the default standard input (for list and read) or
	     standard output (for write).  A single archive may span multiple
	     files and different archive devices.  When required, pax will
	     prompt for the pathname of the file or device of the next volume
	     in the archive.

     -i	     Interactively rename files or archive members.  For each archive
	     member matching a pattern operand or each file matching a file
	     operand, pax will prompt to /dev/tty giving the name of the file,
	     its file mode, and its modification time.	pax will then read a
	     line from /dev/tty.  If this line is blank, the file or archive
	     member is skipped.	 If this line consists of a single period, the
	     file or archive member is processed with no modification to its
	     name.  Otherwise, its name is replaced with the contents of the
	     line.  pax will immediately exit with a non-zero exit status if
	     EOF is encountered when reading a response or if /dev/tty cannot
	     be opened for reading and writing.

     -k	     Do not overwrite existing files.

     -l	     (The lowercase letter "ell.") Link files.	In the copy mode (-r
	     -w), hard links are made between the source and destination file
	     hierarchies whenever possible.

     -n	     Select the first archive member that matches each pattern
	     operand.  No more than one archive member is matched for each
	     pattern.  When members of type directory are matched, the file
	     hierarchy rooted at that directory is also matched (unless -d is
	     also specified).

     -o options
	     Information to modify the algorithm for extracting or writing
	     archive files which is specific to the archive format specified
	     by -x.  In general, options take the form: name=value.

     -p string
	     Specify one or more file characteristic options (privileges).
	     The string option-argument is a string specifying file character-
	     istics to be retained or discarded on extraction.	The string
	     consists of the specification characters a, e, m, o, and p.  Mul-
	     tiple characteristics can be concatenated within the same string
	     and multiple -p options can be specified.	The meaning of the
	     specification characters are as follows:

	     a	 Do not preserve file access times.  By default, file access
		 times are preserved whenever possible.

	     e	 'Preserve everything', the user ID, group ID, file mode bits,
		 file access time, and file modification time.	This is
		 intended to be used by root, someone with all the appropriate
		 privileges, in order to preserve all aspects of the files as
		 they are recorded in the archive.  The e flag is the sum of
		 the o and p flags.

	     m	 Do not preserve file modification times.  By default, file
		 modification times are preserved whenever possible.

	     o	 Preserve the user ID and group ID.

	     p	 'Preserve' the file mode bits.	 This is intended to be used
		 by a user with regular privileges who wants to preserve all
		 aspects of the file other than the ownership.	The file times
		 are preserved by default, but two other flags are offered to
		 disable this and use the time of extraction instead.

	     In the preceding list, 'preserve' indicates that an attribute
	     stored in the archive is given to the extracted file, subject to
	     the permissions of the invoking process.  Otherwise the attribute
	     of the extracted file is determined as part of the normal file
	     creation action.  If neither the e nor the o specification char-
	     acter is specified, or the user ID and group ID are not preserved
	     for any reason, pax will not set the S_ISUID (setuid) and S_ISGID
	     (setgid) bits of the file mode.  If the preservation of any of
	     these items fails for any reason, pax will write a diagnostic
	     message to standard error.	 Failure to preserve these items will
	     affect the final exit status, but will not cause the extracted
	     file to be deleted.  If the file characteristic letters in any of
	     the string option-arguments are duplicated or conflict with each
	     other, the one(s) given last will take precedence.	 For example,
	     if
		   -p eme
	     is specified, file modification times are still preserved.

     -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 expres-
	     sions.  The format of these regular expressions are:
		   /old/new/[gp]
	     As in ed(1), old is a basic regular expression and new can con-
	     tain an ampersand ('&'), '\n' (where n is a digit) back-refer-
	     ences, or subexpression matching.	The old string may also con-
	     tain 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 suc-
	     cessful 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:
		    >> 
	     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 modifica-
	     tion 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:
		    == 
	     For pathnames representing a symbolic link, the output has the
	     format:
		    => 
	     Where  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.  pax 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 BSD4.3.  The default
		      blocksize for this format is 10240 bytes.	 Pathnames
		      stored by this format must be 100 characters or less in
		      length (including the trailing   character, which means
		      that filenames can have a maximum length of 99 charac-
		      ters).  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.	 Filenames
		      stored by this format must be 100 characters or less in
		      length (including the trailing   character, which means
		      that filenames can have a maximum length of 99 charac-
		      ters).  Pathnames (directorynames + filenames) stored by
		      this format must be 250 characters or less in length.

	     pax will detect and report any file that it is unable to store or
	     extract as the result of any specific archive format restric-
	     tions.  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 recom-
	     mended.

     -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., 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 archive 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 physi-
	     cal 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 prema-
	     turely, pax will not prompt for a new volume.  This option can be
	     useful for automated tasks where error recovery cannot be per-
	     formed 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 sup-
	     plied, 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., 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:
		   [[[[[cc]yy]mm]dd]HH]MM[.SS]
	     Where cc is the first two digits of the year (the century), 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), 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, cc.
	     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 sup-
	     plied 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 IDs.

     -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 modifi-
	     cation 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.

ENVIRONMENT
     TMPDIR	 Path in which to store temporary files.

EXAMPLES
     $ pax -w -f /dev/rst0 .

     Copies the contents of the current directory to the device /dev/rst0.

     $ pax -v -f filename

     Gives the verbose table of contents for an archive stored in filename.

     $ mkdir newdir; cd olddir; pax -rw . newdir

     This sequence of commands will copy the entire olddir directory hierarchy
     to newdir.

     $ pax -r -s ',^//*usr//*,,' -f a.pax

     Reads the archive a.pax, with all files rooted in /usr into the archive
     extracted relative to the current directory.

     $ pax -rw -i . dest_dir

     Can be used to interactively select the files to copy from the current
     directory to dest_dir.

     $ pax -r -pe -U root -G bin -f a.pax

     Extract all files from the archive a.pax which are owned by root with
     group bin and preserve all file permissions.

     $ pax -r -w -v -Y -Z home /backup

     Update (and list) only those files in the destination directory /backup
     which are older (less recent inode change or file modification times)
     than files with the same name found in the source file tree home.

DIAGNOSTICS
     pax will exit with one of the following values:

     0	 All files were processed successfully.

     1	 An error occurred.

     Whenever pax cannot create a file or a link when reading an archive or
     cannot find a file when writing an archive, or cannot preserve the user
     ID, group ID, or file mode when the -p option is specified, a diagnostic
     message is written to standard error and a non-zero exit status will be
     returned, but processing will continue.  In the case where pax cannot
     create a link to a file, pax will not create a second copy of the file.

     If the extraction of a file from an archive is prematurely terminated by
     a signal or error, pax may have only partially extracted a file the user
     wanted.  Additionally, the file modes of extracted files and directories
     may have incorrect file bits, and the modification and access times may
     be wrong.

     If the creation of an archive is prematurely terminated by a signal or
     error, pax may have only partially created the archive which may violate
     the specific archive format specification.

     If while doing a copy, pax detects a file is about to overwrite itself,
     the file is not copied, a diagnostic message is written to standard error
     and when pax completes it will exit with a non-zero exit status.

SEE ALSO
     cpio(1), tar(1)

STANDARDS
     The pax utility is a superset of the IEEE Std 1003.2 ("POSIX.2") stan-
     dard.  The options -B, -D, -E, -G, -H, -L, -O, -P, -T, -U, -Y, -Z, the
     archive formats bcpio, sv4cpio, sv4crc, tar, and the flawed archive han-
     dling during list and read operations are extensions to the POSIX stan-
     dard.

AUTHORS
     Keith Muller at the University of California, San Diego.

BSD				April 18, 1994				   BSD