-0 Use the NUL (`\0') character as a pathname terminator, instead of newline (`\n').
When pathnames read from standard input in the write and copy modes, and to the pathnames written to standard output
in list mode. Useful with find -print0 and xargs -0 .
| -a Append the files to the end of an existing archive
It is an error to attemp to change archive formats.
The blocking size used in the archive volume where writing starts will
continue to be used for the remainder of that archive volume.
Warning: Some devices do not support append and may damage the archive or have unpredictable
results. Tape drives in particular are more likely to not support an append operation.
| -B bytes
Limit the size of an archive to bytes .
Suffixes `m', `k', or `b' to specify multiplication by 1048576 (1M), 1024 (1K) or 512. A pair of bytes limits can be
separated by `x' to indicate a product. For example 5xk
: 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).
DO NOT use of this option with a floppy or hard disk.
| -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 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 bzip2 to compress (decompress) the archive while writing (reading). The bzip2 utility must be installed
separately. Incompatible with -a.
| -k Do not overwrite existing files.
| -L Follow all symbolic links to perform a logical file system traversal.
| -l
† 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 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.
| | | | | |
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.
in 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 set the access times of any file or directory accessed to the same as they were before being accessed
| -U user Select a file based on its user name, or (when starting with a #) a numeric UID.
Use \ to escape the #. Warning: UID do not necessarily specify the same user on different systems.
Multiple -U options may be supplied. Checking stops with the first match.
| -D as with -u , except that the file change time is checked instead of the
modification time. The change time can be used to select files whose information (e.g., UID,
GID, etc.) is newer than a copy of the file in the destination directory.
| -Y as with -D except that the change time is checked using the pathname created
after all the file name modifications have completed.
| -u Ignore files older (having a less recent file modification time) than a existing file or archive
member with the same name.
During read, an archive member will be extracted if it is newer than an existing file.
During write, a file system file will replace a memeber if it is newer .
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.
| -Z as -u except that the modification time is checked using the pathname created
after all the file name modifications have completed.
| -v During a list operation, verbose as produce by ls -l .
For 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
Pathnames are written and flushed to standard error
without a trailing newline when processing begins. The trailing newline is
written after the file has been proessed.
-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 .
-X do not descend into directories that have a different
device ID. See the st_dev field as described in stat(2)
| -x format archive format, default ustar.
ustar extended tar (IEEE Std 1003.2 ("POSIX.2") standard). The default blocksize 10240, Filenames must be less than 101 characters ; the total pathname must be less than 256
| cpio The extended cpio interchange format specified in the IEEE Std 1003.2 ("POSIX.2") standard. The default blocksize 5120 .
| sv4cpio The System V release 4 cpio. default blocksize 5120 bytes.
| sv4crc The System V release 4 cpio with file CRC checksums. The default blocksize 5120
| tar BSD tar format 4.3BSD. default blocksize 10240 .
Pathnames must less than 101 characters. Only regular files, hard
links, soft links, and directories are supported.
-o when writing an archive
omits the storage of directories. This option takes the form:
-o write_opt=nodir
Files that cannot be stored or extracted as the result of archive restrictions are reported.
| -z Use gzip(1) to compress (decompress) the archive. Incompatible with -a.
| --insecure Normally ignores filenames or symbolic links that contain ".." as a path component. With this option, files that contain ".." can be processed.
| | | | | | | |
Options that operate on the names (-c, -i, -j, -n, -s, -u, -v, -D, -G, -T, -U, -Y, and -Z ) interact.
When extracting files, archive members are selected, based on the specified pattern
operands as modified by -c, -n, -u, -D, -G, -T, -U .
Then -s and -i will modify in that order,
the names of these selected files.
Then -Y and -Z will be applied based on the final pathname.
Finally, -v will write the resulting name.
When archiving or copying files, archive members are `selected',
based on the specified pathnames as modified by -n, -u, -D, -G, -T, and -U (-D only
applies during a copy ).
Then -s and -i will modify in that order, the names of these selected
files.
Then during a copy -Y and -Z will be applied based on the final pathname.
Finally, -v will write the resulting names.
When -u or -D are specified with -n , a file is not selected unless
it is newer than the file to which it is compared.
ENVIRONMENT
$TMPDIR Path in which to store temporary files.
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
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
cpio(1), tar(1)
"Archiving with Pax", Dru Lavigne, ONLamp.com BSD DevCenter,
onlamp.com/pub/a/bsd/2002/08/22/FreeBSD_Basics.html
pax(1) manual page, http://heirloom.sourceforge.net/man/pax.1.html
compliant with the IEEE Std 1003.1-2004 ("POSIX.1") specification.
-0BDEGHjLOPTUYZz , the archive formats bcpio, sv4cpio, sv4crc, tar, and the flawed archive handling during
list and read operations are extensions to that specification.
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