PAX(1) | General Commands Manual | PAX(1) |
pax
—
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 |
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 following
functional modes pax
will operate under:
list, read, write, and
copy.
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
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
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
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).
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
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 member, pax
will write these file operand pathnames in a
diagnostic message to standard error
and then exit
with a non-zero exit status.
-r
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
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.-w
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
-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
blocksizek
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
-d
-f
archivestandard
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
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
-k
-l
-r
-w
), hard links are
made between the source and destination file hierarchies whenever
possible.-n
-d
is also specified).-o
options-x
. In general, options take
the form: name=value
-p
stringa
,
e
, m
,
o
, and p
. Multiple
characteristics can be concatenated within the same string and multiple
-p
options can be specified. The meaning of the
specification characters are as follows:
a
e
e
flag is the sum
of the o
and p
flags.m
o
p
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
-s
replstr/old/new/[gps]
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 except a backslash (\) 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⟩
s
prevents the substitutions from being performed
on symbolic link destinations.-t
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
-v
-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⟩
-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
formatpax
currently
supports the following formats:
pax
and is repaired.pax
and is repaired.pax
and is repaired.pax
and is repaired.-o
option can be used when writing
an archive to omit the storage of directories. This option takes the
form:
-o
write_opt=nodir
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
-
-timestamp
timestamp-
-xz
-z
-A
-B
bytesm
, 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.
-D
-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
limitpax
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#
, a numeric gid. A '\' can be
used to escape the #
. Multiple
-G
options may be supplied and checking stops with
the first match.-H
-L
-M
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-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
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
-T
[from_date][,to_date][/[c][m]]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 seven different fields and each field must contain two digits. The format is:
[[[[[cc]yy]mm]dd]hh]mm[.ss]
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 values. 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
-T
time range can be
supplied and checking stops with the first match.-U
user#
, a numeric uid. A '\' can be
used to escape the #
. Multiple
-U
options may be supplied and checking stops with
the first match.-V
-X
st_dev
field as described in
stat(2) for more information
about device ID's.-Y
-D
option, except
that the inode change time is checked using the pathname created after all
the file name modifications have completed.-Z
-u
option, except
that the modification time is checked using the pathname created after all
the file name modifications have completed.-0
-
-force-local
-
-insecure
pax
ignores filenames that contain
“..” as a path component. With this option, files that
contain “..” can be processed.-
-use-compress-program
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.
pax
will exit with one of the following values:
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.
pax -w -f /dev/rst0 .
The command:
pax -v -f filename
The following commands:
mkdir newdir
cd olddir
pax -rw -pp
. ../newdir
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
The command:
pax -r -s ',^//*usr//*,,' -f
a.pax
The command:
pax -rw -i
. dest_dir
The command:
pax -r -pe -U root -G bin -f
a.pax
The command:
pax -r -w -v -Y -Z home
/backup
pax
utility is a superset of the
IEEE Std 1003.2 (“POSIX.2”) standard.
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
archive handling during list and
read operations are extensions to the POSIX standard.
pax
utility appeared in
4.4BSD.
-M
.
March 19, 2019 | NetBSD 9.4 |