Provided by: pax_20151013-1_amd64 bug

NAME

     pax — read and write file archives and copy directory hierarchies

SYNOPSIS

     pax [-0cdJjnOvz] [-E limit] [-f archive] [-G group] [-s replstr] [-T range] [-U user]
         [pattern ...]
     pax -r [-0cDdiJjknOuvYZz] [-E limit] [-f archive] [-G group] [-M flag] [-o options]
         [-p string] [-s replstr] [-T range] [-U user] [pattern ...]
     pax -w [-0adHiJjLOPtuvXz] [-B bytes] [-b blocksize] [-f archive] [-G group] [-M flag]
         [-o options] [-s replstr] [-T range] [-U user] [-x format] [file ...]
     pax -rw [-0DdHiJjkLlnOPtuvXYZ] [-G group] [-p string] [-s replstr] [-T range] [-U user]
         [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 following functional modes
     pax will operate under: list, read, write, and copy.

     <none>  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 pattern
             arguments.  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 pattern arguments.  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.

     -rw     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 subsequently 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 possible (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 notation described by glob(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.

     The options are as follows:

     -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).

     -a      Append the given file operands to the end of an archive that was previously written.
             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
             immediately 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 operations 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
             particular 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.

     -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.

     -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.  Archive block sizes larger than 32256 bytes violate
             the POSIX standard 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 dependent 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      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.

     -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.

     -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.

     -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.

     -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.

     -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.

     -J      Use the xz utility to compress (decompress) the archive while writing (reading).
             Incompatible with -a.

     -j      Use the bzip2 utility to compress (decompress) the archive while writing (reading).
             Incompatible with -a.

     -k      Do not overwrite existing files.

     -L      Follow all symbolic links to perform a logical file system traversal.

     -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.

     -M flag
             Configure the archive normaliser.  flag is either a numeric value compatible to
             strtonum(3) which is directly stored in the flags word, or one of the following
             values, optionally prefixed with “no-” to turn them off:

             inodes  0x0001: Serialise inodes, zero device info.
                     (cpio, sv4cpio, sv4crc)
             links   0x0002: Store content of hard links only once.
                     (cpio, sv4cpio, sv4crc)
             mtime   0x0004: Zero out the file modification time.
                     (ar, cpio, sv4cpio, sv4crc, ustar)
             uidgid  0x0008: Set owner to 0:0 (root:wheel).
                     (ar, cpio, sv4cpio, sv4crc, ustar)
             verb    0x0010: Debug this option.
             debug   0x0020: Debug file header storage.
             lncp    0x0040: Extract hard links by copy if link fails.
             numid   0x0080: Use only numeric uid and gid values.
                     (ustar)
             gslash  0x0100: Append a slash after directory names.
                     (ustar)
             set     0x0003: Keep ownership and mtime intact.
             dist    0x008B: Clean everything except mtime.
             norm    0x008F: Clean everything.
             root    0x0089: Clean owner and device information.

             When creating an archive and verbosely listing output, these normalisation
             operations are not reflected in the output, because they are made only after the
             output has been shown.

             This option is only implemented for the ar, cpio, sv4cpio, sv4crc, and ustar file
             format writing routines.

             TODO: The pax frontend should be using the -o option for handling this feature
             instead.

     -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      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.

     -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.

             The following options are available for the old BSD tar format:

             nodir
             write_opt=nodir
                     When writing archives, omit the storage of directories.

     -P      Do not follow symbolic links, perform a physical file system traversal.  This is the
             default mode.

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

     -r      Read an archive file from standard input and extract the specified file operands.
             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
             operation.

     -s replstr
             Modify the archive member names according to the substitution expression replstr,
             using the syntax of the ed(1) utility regular expressions.  file or pattern
             arguments may be given to restrict the list of archive members to those specified.

             The format of these regular expressions is:

                   /old/new/[gp]

             As in ed(1), old is a basic regular expression (see re_format(7)) and new can
             contain an ampersand (‘&’), ‘\n’ (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 range
             Allow files to be selected based on a file modification or inode change time falling
             within the specified time range.  The range has the format:

                   [from_date][,to_date][/[c][m]]

             The dates specified by from_date to to_date 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., 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 supplied and checking stops with the first match.

     -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 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.

     -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.

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

     -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.

     -x format
             Specify the output archive format, with the default format being ustar.  pax
             currently supports the following formats:

             ar       The Unix Archiver library format.  This format matches APT repositories and
                      the BSD ar(1) specification, not GNU binutils (which can however read them)
                      or SYSV systems.  See ar(5) on some operating systems for more information.

             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.

             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.

             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 4.3BSD.  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.  Filenames stored by this format must be 100 characters or less in
                      length; the total pathname must be 256 characters or less.

             pax 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.

     -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.

     -z      Use the gzip(1) utility to compress (decompress) the archive while writing
             (reading).  Incompatible with -a.

     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.

EXIT STATUS

     The pax utility exits with one of the following values:

           0       All files were processed successfully.
           1       An error occurred.

EXAMPLES

     Copy the contents of the current directory to the device /dev/rst0:

           $ pax -w -f /dev/rst0 .

     Give the verbose table of contents for an archive stored in filename:

           $ pax -v -f filename

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

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

     Extract files from the archive a.pax.  Files rooted in /usr are extracted relative to the
     current working directory; all other files are extracted to their unmodified path.

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

     This can be used to interactively select the files to copy from the current directory to
     dest_dir:

           $ pax -rw -i . dest_dir

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

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

     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:

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

DIAGNOSTICS

     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, unless -M lncp is given, 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

     ar(1), cpio(1), deb(5), paxcpio(1), paxtar(1), tar(1)

STANDARDS

     The pax utility is, except for the known BUGS listed below, mostly compliant with the IEEE
     Std 1003.1 (“POSIX”) specification.

     The flags -0BDEGHJjLMOPTUYZz, the archive formats ar, bcpio, sv4cpio, sv4crc, tar, and the
     flawed archive handling during list and read operations are extensions to that
     specification.

AUTHORS

     Keith Muller at the University of California, San Diego.

     MirOS extensions by Thorsten Glaser <tg@mirbsd.org>.

BUGS

     The pax file format is not yet supported.  The pattern matching does not match POSIX
     completely either, nor this documentation.