PAX(1)                  NetBSD General Commands Manual                  PAX(1)

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

SYNOPSIS
     pax [-0cdjnOVvz] [-E limit] [-f archive] [-N dbdir] [-s replstr] ...
         [-U user] ... [-G group] ... [-T [from_date][,to_date]] ...
         [pattern ...]
     pax -r [-AcDdijknOuVvYZz] [-E limit] [-f archive] [-N dbdir] [-o options]
         ... [-p string] ... [-s replstr] ... [-U user] ... [-G group] ... [-T
         [from_date][,to_date]] ... [pattern ...]
     pax -w [-AdHijLMOPtuVvXz] [-b blocksize] [[-a] [-f archive]] [-x format]
         [-B bytes] [-N dbdir] [-o options] ... [-s replstr] ... [-U user] ...
         [-G group] ... [-T [from_date][,to_date][/[c][m]]] ... [file ...]
     pax -r -w [-ADdHijkLlMnOPtuVvXYZz] [-N dbdir] [-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.  If the archive file is of the form:
     [[user@]host:]file then the archive will be processed using rmt(8).

     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.

     <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 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 oper-
             and 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).

OPERANDS
     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.

OPTIONS
     The following options are supported:

     -r    Read an archive file from standard input and extract the specified
           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 ar-
           chive 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.

     -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>.

     -a    Append files 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 vol-
           ume 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 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 sup-
           port an append operation.

     -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 32256
           bytes.  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    Cause files of type directory being copied or archived, or archive
           members of type directory being extracted, to match only the direc-
           tory 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 op-
           erand, 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.  Oth-
           erwise, 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 bzip2(1) for compression when reading or writing archive files.

     -k    Do not overwrite existing files.

     -l    Link files.  (The letter ell).  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 ar-
           chive 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 characteristics
           to be retained or discarded on extraction.  The string consists of
           the specification characters a, e, m, o, and p.  Multiple charac-
           teristics 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 privi-
               leges, 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 mod-
               ification 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 cre-
           ation 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.

     -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 (&), \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 com-
           mand 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 for-
           mat:
                 <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, if the user has the appropriate permissions required by
           utime(3).

     -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 desti-
           nation 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>
           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.

           A final summary of archive operations is printed after they have
           been completed.

     -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 informa-
                    tion 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 porta-
                    ble and should not be used when other formats are avail-
                    able.  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 AT&T System V.4 UNIX 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 AT&T System V.4 UNIX 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 types are not
                    supported).  For backward compatibility with even older
                    tar formats, a -o option can be used when writing an ar-
                    chive 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 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 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.

     --gnu
           Recognize GNU tar extensions.

     --xz  Use xz(1) compression, when reading or writing archive files.

     -z    Use gzip(1) compression, when reading or writing archive files.

     -A    Do not strip leading `/'s from file names.

     -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 multi-
           plication 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 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 traver-
           sal.

     -M    During a write or copy operation, treat the list of files on
           standard input as an mtree(8) `specfile' specification, and write
           or copy only those items in the specfile.

           If the file exists in the underlying file system, its permissions
           and modification time will be used unless specifically overridden
           by the specfile.  An error will be raised if the type of entry in
           the specfile conflicts with that of an existing file.  A directory
           entry that is marked `optional' will not be copied (even though its
           contents will be).

           Otherwise, the entry will be `faked-up', and it is necessary to
           specify at least the following parameters in the specfile: type,
           mode, gname or gid, and uname or uid, device (in the case of block
           or character devices), and link (in the case of symbolic links).
           If time isn't provided, the current time will be used.  A
           `faked-up' entry that is marked `optional' will not be copied.

     -N dbdir
           Except for lookups for the -G and -U options, use the user database
           text file master.passwd and group database text file group from
           dbdir, rather than using the results from the system's getpwnam(3)
           and getgrnam(3) (and related) library calls.

     -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 tra-
           versal.  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), the second mm is the minute (from 00 to
           59), and ss is the seconds (from 00 to 61).  Only the minute field
           mm is required; the others will default to the current system val-
           ues.  The ss field may be added independently of the other fields.
           If the century is not specified, it defaults to 1900 for years
           between 69 and 99, or 2000 for years between 0 and 68.  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.

     -V    A final summary of archive operations is printed after they have
           been completed.  Some potentially long-running tape operations are
           noted.

     -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 modifica-
           tion time is checked using the pathname created after all the file
           name modifications have completed.

     -0    Use the nul character instead of \n as the file separator when
           reading files from standard input.

     --force-local
           Do not interpret filenames that contain a `:' as remote files.

     --insecure
           Normally pax ignores filenames that contain ``..'' as a path compo-
           nent.  With this option, files that contain ``..'' can be pro-
           cessed.

     --use-compress-program
           Use the named program as the program to decompress the input or
           compress the output.

     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.

EXIT STATUS
     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.

EXAMPLES
     The command:
           pax -w -f /dev/rst0 .
     copies the contents of the current directory to the device /dev/rst0.

     The command:
           pax -v -f filename
     gives the verbose table of contents for an archive stored in filename.

     The following commands:
           mkdir newdir
           cd olddir
           pax -rw -pp . ../newdir
     will copy the entire olddir directory hierarchy to newdir, preserving
     permissions and access times.

     When running as root, one may also wish to preserve file ownership when
     copying directory trees.  This can be done with the following commands:
           cd olddir
           pax -rw -pe . ../newdir
     which will copy the contents of olddir into ../newdir, preserving owner-
     ship, permissions and access times.

     The command:
           pax -r -s ',^//*usr//*,,' -f a.pax
     reads the archive a.pax, with all files rooted in ``/usr'' into the ar-
     chive extracted relative to the current directory.

     The command:
           pax -rw -i . dest_dir
     can be used to interactively select the files to copy from the current
     directory to dest_dir.

     The command:
           pax -r -pe -U root -G bin -f a.pax
     will extract all files from the archive a.pax which are owned by root
     with group bin and will preserve all file permissions.

     The command:
           pax -r -w -v -Y -Z home /backup
     will 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.

SEE ALSO
     cpio(1), tar(1), symlink(7), mtree(8)

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, -M, -O, -P, -T, -U, -Y, -Z,
     -z, the archive formats bcpio, sv4cpio, sv4crc, tar, and the flawed ar-
     chive handling during list and read operations are extensions to the
     POSIX standard.

AUTHORS
     Keith Muller at the University of California, San Diego.  Luke Mewburn
     implemented -M.

NetBSD 6.0                     November 13, 2013                    NetBSD 6.0

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