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Commands Reference, Volume 4
pax Command
Purpose
Extracts, writes, and lists members of archive files;
copies files and directory hierarchies.
Syntax
To List Member Files of Archived Files
pax [ -c ] [ -d ]
[ -n ] [ -v ] [ -H | -L ] [ -f Archive ] [ -s ReplacementString ... ] [ -x Format ] [ -o Options ] [ Pattern ... ]
To Extract Archive Files Using the -r Flag
pax -r
[ -c ] [ -d ] [ -i ] [ -k ] [ -n ]
[ -u ] [ -v ] [ -H | -L ] [ -f Archive ] [ -o Options ] [ -p String ... ]
[ -s ReplacementString ... ] [ -x Format ] [ Pattern ... ]
To Write Archive Files Using the -w Flag
pax -w
[ -d ] [ -i ] [ -t ] [ -u ] [ -v ] [ -X ]
[ -H | -L ] [ -b Blocking ] [ [ -a ] -f Archive ] [ -o Options ] [ -s ReplacementString ... ] [ -x Format ] [ File ... ]
To Copy Files Using the -r and -w Flags
pax -r -w [ -d ] [ -i ] [ -k ] [ -l ]
[ -n ] [ -t ] [ -u ] [ -v ] [ -X ]
[ -H | -L ] [ -p String ... ]
[ -o Options ] [ -s ReplacementString ... ] [ -x Format ] [ File ... ] Directory
Description
The pax command extracts and
writes member files of archive files; writes lists of the member files of
archives; and copies directory hierarchies. The -r and -w flags specify the type of archive operation.
Note: pax actively sparses
files that are being restored. If a file has block aligned and sized areas
that are NULL populated, pax does not cause physical
space for those filesystem blocks to be allocated. The size in bytes of the
file remains the same, but the actual space taken within the filesystem is
only for the non-NULL areas.
Listing Member Files of Archived Files (List Mode)
When neither the -r nor the -w flags are specified, the pax command
lists all the member files of the archive file read from standard input. If
the Pattern parameter is specified, only the member
files with pathnames that match the specified patterns are written to standard
output. If a named file is a directory, the file hierarchy contained in the
directory is also written. When neither the -r or -w flags are specified, the -c, -d, -f, -n, -s, and -v flags, and the Pattern parameter may be specified.
Extracting Archive Files Using the -r Flag (Read Mode)
When the -r flag is specified,
but the -w flag is not, the pax
command extracts all the member files of the archive files read from standard
input. If the Pattern parameter is specified, only
the member files with pathnames that match the specified patterns are written
to standard output. If a named file is a directory, the file hierarchy contained
in the directory is also extracted. The -r flag can
be specified with the -c, -d, -f, -i, -k, -n, -s, -u,
and -v flags, and with the Pattern parameter.
The access and modification times of the extracted
files are the same as the archived files. The file modes of the extracted
files are the same as when they were archived, unless they are affected by
the user's default file creation mode (umask). The S_ISUID and S_ISGID bits of the extracted
files are cleared.
If intermediate directories are necessary to extract
an archive member, the pax command creates the directories
with access permissions set as the bitwise inclusive OR of the values of the S_IRWXU, S_IRWXG, and S_IRWXO masks.
If the selected archive format supports the specification
of linked files, it is an error if these files cannot be linked when the archive
is extracted.
Writing Archive Files Using the -w Flag (Write Mode)
When the -w flag is specified
and the -r flag is not, the pax
command writes the contents of the files specified by the File parameter to standard output in an archive format. If no File parameter is specified, a list of files to copy, one per line, is
read from the standard input. When the File parameter
specifies a directory, all of the files contained in the directory are written.
The -w flag can be specified with the -a, -b, -d, -f, -i, -o, -s, -t, -u, -v, -x, and -X flags and
with File parameters.
When specifying pathnames that are greater than 100
characters for the United States Tape Archiver (USTAR) format, remember that
the pathname is composed of a prefix buffer, a / (slash), and a name buffer.
The prefix buffer can be a maximum of 155 characters and the name buffer can
hold a maximum of 100 characters. If the pathname cannot be split into these
two parts by a slash, it cannot be archived. This limitation is due to the
structure of tar archive headers, and must be maintained
for compliance with standards and backwards compatibility.
Copying Files Using the -r and -w Flags (Copy Mode)
When both the -r and -w flags are specified, the pax command copies
the files specified by the File parameters to the
destination directory specified by the Directory parameter.
If no files are specified, a list of files to copy, one per line, is read
from the standard input. If a specified file is a directory, the file hierarchy
contained in the directory is also copied. The -r and -w flags can be specified with the -d, -i, -k, -l, -o, -p, -n, -s, -t, -u, -v, and -X flags and with File parameters. The Directory parameter must
be specified.
Copied files are the same as if they were written
to an archive file and subsequently extracted, except that there may be hard
links between the original and the copied files.
Modifying the Archive Algorithm Using the -o Flag
Use the -o flag to modify the
archive algorithm according to keyword-value pairs. The keyword-value pairs
must adhere to a correct archive format. A list of valid keywords and their
behavior is given in the subsequent description of the -o flag.
Further Notes
In read or copy modes, if intermediate directories are necessary to extract
an archive member, pax performs actions equivalent to
the mkdir() subroutine with the intermediate directory
used as the path argument and the value S_IRWXU as the
mode argument.
If any specified pattern or file operands are not matched by at least one
file or archive member, pax writes a diagnostic message
to standard error for each one that did not match and exits with an error
status.
In traversing directories, pax will detect infinite
loops; i.e., entering a previously visited directory that is an ancestor of
the last file visited. Upon detection of an infinite loop, pax writes a diagnostic message to standard error and terminates.
When pax is in read mode or list mode, using the -x pax archive format, and a file name, link name, owner
name, or any other field in an extended header record cannot be translated
from the pax UTF8 codeset format to the current codeset
and locale, pax writes a diagnostic message to standard
error, processes the file as described for the -o invalid= option, and then processes the next file in the archive.
Variables
|
Directory |
Specifies the path of a destination directory when copying files. |
|
File |
Specifies the path of a file to be copied or archived. If no file matches
the File parameter, the pax
command detects the error, exits, and writes a diagnostic message. |
|
Pattern |
Specifies a pattern that matches one or more paths of archive members.
A / (backslash) character is not recognized in the Pattern parameter and it prevents the subsequent character from having
any special meaning. If no Pattern parameter is specified,
all members are selected in the archive.
If a Pattern parameter is specified, but no archive members are found that
match the pattern specified, the pax command detects
the error, exits, and writes a diagnostic message. |
Flags
|
-a |
Appends files to the end of an archive.
Note: Streaming tape devices do not allow append. |
|
-b Blocking |
Specifies the block size for output. The Blocking parameter specifies a positive decimal integer value that specifies
the number of bytes per block. Application conforming to POSIX2 should not
specify a blocksize value greater than 32256. Devices and archive formats
may impose restrictions on blocking. Blocking is automatically determined
on input. Default blocking when creating archives depends on the archive format.
(See the -x flag definition.)
The
value of the Blocking parameter may be one of the
following:
- Integer b
- Specifies that the block size, in bytes, be the value of the positive
decimal integer specified by the Integer parameter
multiplied by 512.
- Integer k
- Specifies that the block size, in bytes, be the value of the positive
decimal integer specified by the Integer parameter
multiplied by 1024.
- Integer m
- Specifies that the block size, in bytes, be the value of the positive
decimal integer specified by the Integer parameter
multiplied by 1024 x 1024.
- Integer+Integer
- Specifies that the block size, in bytes, be the sum of the positive
decimal integers specified by the Integer parameters.
|
|
-c |
Matches all file or archive members except those specified by the Pattern parameter. |
|
-d |
Causes directories being copied, archived, or extracted, to match only
the directory itself and not the contents of the directory. |
|
-f Archive |
Specifies the path of an archive file to be used instead of standard
input (when the -w flag is not specified) or standard
output (when the -w flag is specified but the -r flag is not). When specified with the -a flag
option, any files written to the archive are appended to the end of the archive. |
|
-H |
If a symbolic link referencing a directory is specified on the command
line, pax archives the file hierarchy rooted in the
directory referenced in the link, using the name of the link as the name of
the file hierarchy. By default, pax archives the symbolic
link itself. |
|
-i |
Renames files or archives interactively. For each archive member that
matches the Pattern parameter or file that matches
a File parameter, a prompt is written to the display
device that contains the name of a file or archive member. A line is then
read from the display device. If this line is empty, 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. |
|
-k |
Prevents the pax command from writing over existing
files. |
|
-l |
Links files when copying files. Hard links are established between
the source and destination file hierarchies whenever possible. |
|
-L |
If a symbolic link referencing a directory is specified on the command
line or encountered during the traversal of a file hierarchy, pax archives the file hierarchy rooted in the directory referenced in
the link, using the name of the link as the name of the file hierarchy. By
default, pax archives the symbolic link itself. |
|
-n |
Selects the first archive member that matches each Pattern parameter. No more than one archive member is matched for each
pattern. |
|
-o Options |
Modifies the archiving algorithm according to the keyword-value pairs
specified in the Options parameter. The keyword-value
pairs must be in the following format:
keyword:=value,keyword:=value,...
Some keywords apply only to
certain file formats, as indicated with each description. Use of keywords
that are inapplicable to the file format being processed will be ignored by pax.
Keywords can be preceded with white space.
The value field consists of zero or more characters;
within value, any literal comma must be preceded with
a backslash (\). A comma as the final character, or a comma followed solely
by white space as the final character, in Options
will be ignored. Multiple -o options can be specified.
If keywords given to these multiple -o options conflict,
the keywords and values appearing later in command-line sequences take precedence;
earlier values are ignored.
The following keyword-value pairs are supported
for the indicated file formats:
datastream=pathname,datastr_size=size (Applicable to all file formats.)
The datastream keyword indicates
the incoming archive file is not in a file format; instead, it is a data stream
from the standard input device. Consequently, the data should be archived
as a regular file in a format recognized by the -x flag.
The file name of the data stream should be specified in the pathname parameter and should include the identification of the person
who invoked the command, the group identification, and the umask for the file mode.
Note: The datastream keyword does not have a default variable size.
You must specify one.
The datastr_size keyword denotes the size of the data stream input in bytes
using decimal digits. If the pax command reaches the
end of file (EOF) character before it reads the size
parameter, it pads the archive file with null values. The null values make
the archive file the same size as specified by the size parameter. If the data in the archive file exceeds the size specified,
the pax command truncates the archive file to the size
specified by the size parameter. The pax command also stops taking input and closes the archive file.
Note: You can specify multiple instances of keyword pairs.
If you assign different values to the same keyword, the pax command uses the last value assigned to the keyword to execute the -o flag.
delete=pattern (Applicable only to the -x pax format.)
When used in write or copy mode, pax omits any
keywords matching pattern from the extended header
records that it produces. When used in read or list mode, pax ignores any keywords matching pattern in
the extended header records. In all cases, matching is done using standard
shell pattern-matching notation. For example, -o delete=security.* suppresses security-related information. |
| -o Options (Continued) |
exthdr.name=string (Applicable only to the -x pax format.)
This keyword allows user control over the name written into the ustar header blocks for the extended header records. The
name is the contents of string after the following
character substitutions have been made:
- string includes:
- Replaced by:
- %d
- The directory name of the file, equivalent to the result of the dirname utility on the translated pathname
- %f
- The filename of the file, equivalent to the result of the basename utility on the translated pathname
- %%
- A %% character
Any other % characters in string produce
undefined results. If this keyword-value pair is not specified in the -o Options list, the default value
of the name is:
%d/PaxHeaders/%f
globexthdr.name=string (Applicable only to the -x pax format.)
When used in write or copy mode with the appropriate
options, pax creates global extended header records
with ustar header blocks that will be treated as regular
files by previous versions of pax. This keyword allows
user control over the name that is written into the ustar header blocks for global extended header records. The name is the contents
of string after the following character substitutions
have been made:
- string includes:
- Replaced by:
- %n
- An integer that represents the sequence number of the global extended
header record in the archive starting at 1
- %%
- A % character
Any other % characters in string produce
undefined results. If this keyword-value pair is not specified in the -o Options list, the default value
of the name is
$TMPDIR/GlobalHead.%n
where $TMPDIR is either the value of the TMPDIR environment variable or /tmp if TMPDIR is unset.
invalid=action (Applicable only to the -x pax format.)
This keyword allows user control over the action pax takes upon encountering values in an extended header record that:
- in read or copy mode, are invalid in the destination hierarchy, or
- in list mode, cannot be written in the codeset and current locale.
|
| -o Options (Continued) |
pax recognizes these invalid values:
- In read or copy mode, a filename or link name that contains character
encodings invalid in the destination hierarchy. (For example, the name may
contain embedded NULLs.)
- In read or copy mode, a filename or link name that is longer than the
maximum allowed in the destination hierarchy (for either a pathname component
or the entire pathname).
- In list mode, any character string value (filename, link name, user name,
etc.) that cannot be written in the codeset and current locale.
These mutually exclusive values of the action argument are supported:
- bypass
In read or copy mode, pax bypasses the file, causing no change to the destination hierarchy.
In list mode, pax writes all requested valid values
for the file, but its method for writing invalid values is unspecified.
- rename
In read or copy mode, pax acts as if the -i flag is in effect for each
file with invalid filename or link name values, allowing the user to provide
a replacement name interactively. In list mode, pax
behaves identically to the bypass action.
- UTF8
When used in read, copy, or list mode and
a filename, link name, owner name, or any other field in an extended header
record cannot be translated from the pax UTF8 codeset
format to the current codeset and locale, pax uses the
actual UTF8 encoding for the name.
- write
In read or copy mode, pax writes the file, translating or truncating the name, regardless of
whether this may overwrite an existing file with a valid name. In list mode, pax behaves identically to the bypass
action.
If no -o invalid=action is specified, pax acts as if the bypass action is specified. Any overwriting of existing files that may
be allowed by the -o invalid=actions is subject to permission (-p) and modification
time (-u) restrictions, and is suppressed if the -k flag is also specified.
linkdata (Applicable only to the -x pax format.)
In write mode, pax writes
the contents of a file to the archive, even when that file is merely a hard
link to a file whose contents have already been written to the archive. |
| -o Options (Continued) |
listopt=format (Applicable
to all file formats.)
This keyword specifies the output format of the
table of contents produced when the -v option is specified
in list mode. To avoid ambiguity, this keyword-value pair should be used as
the only or final keyword-value pair following the -o
flag; all characters in the remainder of the option-argument are considered
part of the format string. If multiple -o listopt=format options are specified, the format strings are considered to be a single,
concatenated string, evaluated in command-line order. Please refer to the List-Mode Format Specifications
section for more information.
times (Applicable
only to the -x pax format.)
When used in write
or copy mode, pax includes atime, ctime, and mtime extended
header records for each file. |
Extended header keywords
(Applicable only to the -x pax format.)
If the -x pax format is specified, any of the keywords
and values defined in the list below can be used as parameters to the -o flag, in either of two modes:
keyword=value
When used in write or copy mode, these keyword-value pairs are written
into the global extended header records of the new archive. When used in read
or list mode, these keyword-value pairs act as if they were present in the
global extended header records of the archive being read. In both cases, the
given value is applied to all files that do not have a value assigned in their
individual extended header records for the specified keyword.
keyword:=value
When used in write or copy mode, these keyword-value pairs are written
into the extended header records of each file in the new archive. When used
in read or list mode, these keyword-value pairs act as if they were present
in the extended header records of each file in the archive being read. In
both cases, the given value overrides any value for the specified keyword
found in global or file-specific extended header records.
atime
The file access time for the following file(s), equivalent to the value
of the st_atime member of the stat structure for a file.
charset
The name of the character set used to encode the data in the following
file(s). The entries in this table are defined to refer to known standards:
| value |
Formal Standard |
| "ISO-IR 646 1990" |
ISO/IEC 646 IRV |
| "ISO-IR 8859 1 1987" |
ISO 8859-1 |
| "ISO-IR 8859 2 1987" |
ISO 8859-2 |
| "ISO-IR 10646 1993" |
ISO/IEC 10646 |
| "ISO-IR 10646 1993 UTF8" |
ISO/IEC 10646, UTF8 encoding |
| "BINARY" |
None |
The encoding is included in an extended header for information only; when pax is used as described, it does not translate the file
data into any other encoding. The BINARY entry indicates binary data that
is not encoded.
comment
A series of characters used as a comment. All characters in the value field
are ignored by pax.
ctime
The file creation time for the following file(s), equivalent to the value
of the st_ctime member of the stat structure for a file.
gid
The group ID of the group that owns the file, expressed as a decimal number
using digits from ISO/IEC 646. This record overrides the gid field in the following header block(s). When used in write or copy
mode, pax includes a gid extended header record for
each file whose group ID is greater than 99,999,999.
gname
The group of the following file(s), formatted as a group name in the group
database. This record overrides the gid and gname fields in the following header blocks, and any gid extended header record. When used in read, copy, or list mode, pax translates the name from the UTF8 encoding in the header
record to the character set appropriate for the group database on the receiving
system. If any of the UTF8 characters cannot be translated, and if the -o invalid=UTF8 option is not specified, the results are
undefined. When used in write or copy mode, pax includes
a gname extended header record for each file whose group name cannot be represented
entirely with the letters and digits of the portable character set.
linkpath
The pathname of a link being created to another file, of any type, previously
archived. This record overrides the linkname field
in the following ustar header block(s).
The following ustar header block determines the type
of link created, whether hard or symbolic. In the latter case, the linkpath
value is the contents of the symbolic link. pax translates
the name of the link (contents of the symbolic link) from the UTF8 encoding
to the character set appropriate for the local file system.
When used in write or copy mode, pax includes a linkpath
extended header record for each link whose pathname cannot be represented
entirely with the members of the portable character set other than NULL.
mtime
The file modification time of the following file(s), equivalent to the
value of the st_mtime member of the stat structure for a file. This record
overrides the mtime field in the following header
block(s). The modification time is restored if the process has the appropriate
privilege to do so.
path
The pathname of the following file(s). This record overrides the name and prefix fields in the following header
block(s). pax translates the pathname of the file from
the UTF8 encoding to the character set appropriate for the local file system.
When used in write or copy mode, pax includes a path
extended header record for each file whose pathname cannot be represented
entirely with the members of the portable character set other than NULL.
realtime.any
The keywords prefixed by realtime are reserved for future POSIX realtime
standardization. pax recognizes but silently ignores
them.
security.any
The keywords prefixed by security are reserved for future POSIX security
standardization. pax recognizes but silently ignores
them.
size
The size of the file in octets, expressed as a decimal number using digits
from ISO/IEC 646. This record overrides the size field
in the following header block(s). When used in write or copy mode, pax includes a size of extended header record for each file with a size
value greater than 999,999,999,999.
uid
The user ID of the user that owns the file, expressed as a decimal number
using digits from ISO/IEC 646.. This record overrides the uid field in the following header block(s). When used in write or copy
mode, pax includes a uid extended header record for
each file whose owner ID is greater than 99,999,999.
uname
The owner of the following file(s), formatted as a user name in the user
database. This record overrides the uid and uname fields in the following header block(s), and any uid extended header record. When used in read, copy, or list mode, pax translates the name from the UTF8 encoding in the header
record to the character set appropriate for the user database on the receiving
system. If any of the UTF8 characters cannot be translated, and if the -o invalid=UTF8 option is not specified, the results are
undefined. When used in write or copy mode, pax includes
a uname extended header record for each file whose user name cannot be represented
entirely with the letters and digits of the portable character set.
If the value field is zero length, it deletes any
header block field, previously entered extended header value, or global extended
header value of the same name.
If a keyword in an extended header record (or in a -o option-argument) overrides or deletes a corresponding field in the ustar header block, pax ignores the
contents of that header block field.
Extended header keyword precedence
(Applicable only to the -x pax format.)
This section describes the precedence in which the various header records
and fields and command-line options are selected to apply to a file in the
archive. When pax is used in read or list modes, it
determines a file attribute in this sequence:
- If -o delete=keyword-prefix
is used, the affected attribute is determined from step (7) if applicable,
or ignored otherwise.
- If -o keyword:=NULL is used, the affected attribute
is ignored.
- If -o keyword:=value is
used, the affected attribute is assigned the value.
- If value exists in a file-specific extended header
record, the affected attribute is assigned the value. When extended header
records conflict, the last one given in the header takes precedence.
- If -o keyword=value is used,
the affected attribute is assigned the value.
- If a value exists in a global extended header record, the affected attribute
is assigned the value. When global extended header records conflict, the last
one given in the global header takes precedence.
- Otherwise, the attribute is determined from the ustar header block.
|
-p String |
Specifies one or more file characteristics to be retained or discarded
on extraction. The String parameter consists of the
characters a, e, m, o, and p. Multiple characteristics
can be concatenated within the same string and multiple -p flags can be specified. The specifications have the following meanings:
- a
- Does not retain file-access times.
- e
- Retains the user ID, group ID, file mode, access time, and modification
time.
- m
- Does not retain file-modification times.
- o
- Retains the user ID and the group ID.
- p
- Retains the file modes.
If neither the -e nor the -o flag is specified, or the user ID and group ID are not
preserved for any reason, the pax command does not set
the S_ISUID and S_ISGID bits of
the file mode. If the retention of any of these items fails, the pax command writes a diagnostic message to standard error. Failure to
retain any of the items affects the exit status, but does not cause the extracted
file to be deleted. If specification flags are duplicated or conflict with
each other, the last flag specified takes precedence. For example, if -p eme is specified, file-modification times are
retained. |
|
-r |
Reads an archive file from the standard input. |
|
-s ReplacementString |
Modifies file- or archive-member names specified by the Pattern or File parameters according to the substitution
expression ReplacementString, using the syntax of
the ed command. The substitution expression has the
following format:
-s /old/new/[gp]
where (as in the ed command), old is a basic regular expression and new can contain
an & (ampersand), \n (n is a digit) back references, or subexpression matching.
The old string can also contain new-line characters.
Any non-null character can be used as a delimiter (the
/ (backslash) is the delimiter in the example). Multiple -s flag expressions can be specified; the expressions are applied in
the order specified, terminating with the first successful substitution. The
optional trailing g character performs as in the ed command. The optional trailing p character causes successful substitutions to be written to standard
error. File or archive-member names that substitute to the empty string are
ignored when reading and writing archives. |
|
-t |
Causes the access times of input files to be the same as they were
before being read by the pax command. |
|
-u |
Ignores files that are older than a preexisting file or archive member
with the same name.
- When extracting files, an archive member with the same
name as a file in the file system is extracted if the archive member is newer
than the file.
- When writing files to an archive file, an archive member
with the same name as a file in the file system is superseded if the file
is newer than the archive member. If the -a flag is
specified this is accomplished by appending to the archive. Otherwise it is
unspecified if this is accomplished by actual replacement in the archive or
by appending to the archive.
- When copying files to a destination directory, 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 |
Writes information about the process. If neither the -r or -w flags are specified, the -v flag produces a verbose table of contents; otherwise, archive member
pathnames are written to standard error. |
|
-w |
Writes files to the standard output in the specified archive format. |
|
-x Format |
Specifies the output archive format. The pax
command recognizes the following formats:
- pax
- The default interchange format. The default blocking value for this
format for character-special archive files is 10240. Blocking values from
512 to 32256 in increments of 512 are supported.
- cpio
- Extended cpio interchange format. The default
blocking value for this format for character-special archive files is 5120.
Blocking values from 512 to 32256 in increments of 512 are supported.
- ustar
- Extended tar interchange format. The default
blocking value for this format for character-special archive files is 10240.
Blocking values from 512 to 32256 in increments of 512 are supported.
Any attempt to append to an archive file in a format
different from the existing archive format causes the pax command to exit immediately with a nonzero exit status.
In copy
mode, if no -x format is specified, pax behaves as if -x pax were specified. |
|
-X |
When traversing the file hierarchy specified by a pathname, the pax command does not descend into directories that have
a different device ID. |
Flag Interaction and Processing Order
The flags that operate on the names of files or archive
members (-c, -i, -n, -s, -u, and -v) interact as follows:
- When extracting files, archive members are selected
according to the user-specified pattern parameters
as modified by the -c, -n, and -u flags. Then, any -s, and -i flags modify, in that order, the names of the selected files. The -v flag writes the names resulting from these modifications.
- When writing files to an archive file, or when
copying files, the files are selected according to the user-specified pathnames
as modified by the -n and -u flags.
Then, any -s, and -i flags modify,
in that order, the names resulting from these modifications. The -v flag writes the names resulting from the modification.
- If both the -u and -n flags are specified, the pax command does not
consider a file selected unless it is newer than the file to which it is compared.
List Mode Format Specifications
In list mode with the -o listopt=format option, the format argument is applied for each selected file. pax appends a newline character to the listopt output for each selected file. The format argument is used as
the format string described in printf(), with the following
exceptions:
- The sequence keyword can occur before a format
conversion specifier. The conversion argument is defined by the value of keyword. The following keywords are supported:
- Any of the field name entries for ustar and cpio header blocks.
- Any keyword defined for the extended header or provided as an extension
within the extended header.
For example, the sequence %(charset)s
is the string value of the name of the character set in the extended header.
The result of the keyword conversion argument is the value from the
applicable header field or extended header, without any trailing NULLs.
All keyword-values used as conversion arguments are translated from the UTF8
encoding to the character set appropriate for the local file system, user
database, etc., as applicable.
- An additional conversion character, T, specifies
time formats. The T conversion character can be preceded
by the sequence keyword=subformat, where subformat is a date format allowed by the date
command. The default keyword is mtime and the default
subformat is: %b %e %H:%M %Y.
- An additional conversion character, M, specifies
the file mode string as displayed by the ls -l command.
If keyword is omitted, the mode
keyword is used. For example, %.1M writes the single character corresponding
to the entry type field of the ls
-l command.
- An additional conversion character, D, specifies
the device for block or special files, if applicable. If not applicable and keyword is specified, then this conversion is equivalent
to %keyword u. If not applicable and keyword is omitted, this conversion is equivalent to <space>.
- An additional conversion character, F, specifies
a pathname. The F conversion character can be preceded
by a sequence of comma-separated keywords:
keyword,keyword...
The values for all the non-null keywords are concatenated
together, each separated by a /. The default is path
if the keyword path is defined; otherwise, the default is prefix,name.
- An additional conversion character, L, specifies
a symbolic link expansion. If the current file is a symbolic link, then %L
expands to:
"%s -> %s", value_of_keyword, contents_of_link
Otherwise, the %L conversion
character is equivalent to %F.
Exit Status
This command returns the following exit values:
|
0 |
Successful completion. |
|
>0 |
An error occurred. |
Examples
- To copy the olddir
directory hierarchy to newdir, enter:
mkdir newdir
pax -rw olddir newdir
- To copy the contents of the current directory
to the tape drive, enter:
pax -wf /dev/rmt0
- To archive the file xxx as XXX and display the successful substitution,
enter:
pax -wvf/dev/rfd0 -s /xxx/XXX/p xxx
OR
pax -wvf/dev/rfd0 -s/x/X/gp xxx
- To read a file from a standard input and
dump it to a datastream file with a specified size, enter:
dd if=/dev/hd6 bs=36b count=480 | pax -wf /dev/rfd0 -o
datastream=_filename_,datastr_size=_size_
Files
|
/usr/bin/pax |
Contains the pax command. |
Related Information
The ed
command, cpio command, tar command, and rmt command.
The Files Overview in AIX 5L Version 5.2 System User's Guide: Operating System and Devices.
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