NAME¶
paxtar —
tape archiver
SYNOPSIS¶
paxtar |
{crtux}[014578AabefHhJjLmNOoPRSpqsvwXZz]
[blocking-factor | archive | replstr]
[-C directory]
[-I file]
[file ...] |
paxtar |
{-crtux}
[-014578AaeHhJjLmNOoPpqRSvwXZz]
[-b blocking-factor]
[-C directory]
[-f archive]
[-I file]
[-M flag]
[-s replstr]
[file ...] |
DESCRIPTION¶
The
paxtar command creates, adds files to, or extracts files
from an archive file in “tar” format. A tar archive is often
stored on a magnetic tape, but can be stored equally well on a floppy, CD-ROM,
or in a regular disk file.
In the first (legacy) form, all option flags except for
-C and
-I must be contained within the first argument to
paxtar and must not be prefixed by a hyphen
(‘-’). Option arguments, if any, are processed as subsequent
arguments to
paxtar and are processed in the order in which
their corresponding option flags have been presented on the command line.
In the second and preferred form, option flags may be given in any order and are
immediately followed by their corresponding option argument values.
One of the following flags must be present:
- -c
- Create new archive, or overwrite an existing archive,
adding the specified files to it.
- -r
- Append the named new files to existing archive. Note that
this will only work on media on which an end-of-file mark can be
overwritten.
- -t
- List contents of archive. If any files are named on the
command line, only those files will be listed. The
file arguments may be specified as glob patterns
(see glob(3) for more information), in which case
paxtar will list all archive members that match each
pattern.
- -u
- Alias for -r.
- -x
- Extract files from archive. If any files are named on the
command line, only those files will be extracted from the archive. The
file arguments may be specified as glob patterns
(see glob(3) for more information), in which case
paxtar will extract all archive members that match each
pattern.
If more than one copy of a file exists in the archive, later copies will
overwrite earlier copies during extraction. The file mode and modification
time are preserved if possible. The file mode is subject to modification
by the umask(2).
In addition to the flags mentioned above, any of the following flags may be
used:
- -A
- Write Unix Archiver libraries instead of tape
archives.
- -a
- Guess the compression utility based on the archive
filename. Inability to guess will result in quietly not using any
compression. This option only exists for semi-compatibility with GNU
tar; it is strongly recommended to archive to stdout and
pipe into an external compression utility with appropriate arguments
instead:
tar -cf - foo | xz -2e
>foo.txz
- -b
blocking-factor
- Set blocking factor to use for the archive.
paxtar uses 512-byte blocks. The default is 20, the
maximum is 126. Archives with a blocking factor larger than 63 violate the
POSIX standard and will not be portable to all systems.
- -C
directory
- This is a positional argument which sets the working
directory for the following files. When extracting, files will be
extracted into the specified directory; when creating, the specified files
will be matched from the directory.
- -e
- Stop after the first error.
- -f
archive
- Filename where the archive is stored. Defaults to
/dev/rst0.
- -H
- Follow symlinks given on the command line only.
- -h
- Follow symbolic links as if they were normal files or
directories. In extract mode this means that a directory entry in the
archive will not overwrite an existing symbolic link, but rather what the
link ultimately points to.
- -I
file
- This is a positional argument which reads the names of
files to archive or extract from the given file, one per line.
- -J
- Use the xz utility to compress the archive.
- -j
- Use the bzip2 utility to compress the archive.
- -L
- Synonym for the -h option.
- -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.
This option is only implemented for the ar, cpio, sv4cpio, sv4crc, and ustar
file format writing routines.
- -m
- Do not preserve modification time.
- -N
- Same as -M
numid.
- -O
- If reading, extract files to standard output.
If writing, write old-style (non-POSIX) archives.
- -o
- Don't write directory information that the older (V7) style
tar is unable to decode. This implies the
-O flag.
- -P
- Do not strip leading slashes (‘/’) from
pathnames. The default is to strip leading slashes.
- -p
- Preserve user and group ID as well as file mode regardless
of the current umask(2). The setuid and setgid bits are
only preserved if the user is the superuser. Only meaningful in
conjunction with the -x flag.
- -q
- Select the first archive member that matches each
file operand. No more than one archive member is
matched for each file. When members of type
directory are matched, the file hierarchy rooted at that directory is also
matched.
- -R
- Write SysVR4 CPIO files instead of tar or POSIX ustar
files. Serialise inode numbers, zero out device information. The file
content of hard links is stored only once.
- -S
- Write SysVR4 CPIO files with CRC instead of tar or POSIX
ustar files. Serialise inode numbers, zero out device information. The
file content of hard links is stored only once.
- -s
replstr
- Modify the archive member names according to the
substitution expression replstr, using the syntax of
the ed(1) utility regular expressions.
file 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.
- -v
- Verbose operation mode.
- -w
- Interactively rename files. This option causes
paxtar to prompt the user for the filename to use when
storing or extracting files in an archive.
- -X
- Do not cross mount points in the file system.
- -Z
- Use the compress(1) utility to compress
the archive.
- -z
- Use the gzip(1) utility to compress the
archive.
The options [
-014578] can be used to
select one of the compiled-in backup devices,
/dev/rstN.
ENVIRONMENT¶
TMPDIR
- Path in which to store temporary files.
TAPE
- Default tape device to use instead of
/dev/rst0.
FILES¶
- /dev/rst0
- default archive name
EXIT STATUS¶
The
paxtar utility exits with one of the following values:
- 0
- All files were processed successfully.
- 1
- An error occurred.
EXAMPLES¶
Create an archive on the default tape drive, containing the files named
bonvole and
sekve:
$ paxtar c bonvole sekve
Output a
gzip(1) compressed archive containing the files
bonvole and
sekve to a file called
foriru.tar.gz:
$ paxtar zcf foriru.tar.gz bonvole
sekve
Verbosely create an archive, called
backup.tar.gz, of all
files matching the shell
glob(3) function
*.c:
$ paxtar zcvf backup.tar.gz *.c
Verbosely list, but do not extract, all files ending in
.jpeg
from a compressed archive named
backup.tar.gz. Note that the
glob pattern has been quoted to avoid expansion by the shell:
$ paxtar tvzf backup.tar.gz
'*.jpeg'
For more detailed examples, see
pax(1).
DIAGNOSTICS¶
Whenever
paxtar cannot create a file or a link when extracting
an archive or cannot find a file while writing an archive, or cannot preserve
the user ID, group ID, file mode, or access and modification times when the
-p option is specified, a diagnostic message is written to
standard error and a non-zero exit value will be returned, but processing will
continue. In the case where
paxtar cannot create a link to a
file, unless
-M lncp is given,
paxtar 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,
paxtar may have only partially extracted
the 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,
paxtar may have only partially created the archive, which
may violate the specific archive format specification.
SEE ALSO¶
ar(1),
cpio(1),
pax(1),
paxcpio(1),
tar(1),
deb(5)
HISTORY¶
A
tar command first appeared in
Version 7 AT&T UNIX.
AUTHORS¶
Keith Muller at the University of California, San Diego.
MirOS extensions by
Thorsten Glaser
⟨tg@mirbsd.org⟩.
CAVEATS¶
The flags
-AaJjLMNRS are not portable to other implementations
of
tar where they may have a different meaning or not exist
at all.
BUGS¶
The
pax file format is not yet supported.