AR(1) User Commands AR(1)


NAME


ar - maintain portable archive or library

SYNOPSIS


/usr/bin/ar -d [-Vv] archive file...


/usr/bin/ar -m [-abiVv] [posname] archive file...


/usr/bin/ar -p [-sVv] archive [file]...


/usr/bin/ar -q [-cVv] archive file...


/usr/bin/ar -r [-abciuVv] [posname] archive file...


/usr/bin/ar -t [-sVv] archive [file]...


/usr/bin/ar -x [-CsTVv] archive [file]...


/usr/xpg4/bin/ar -d [-Vv] archive file...


/usr/xpg4/bin/ar -m [-abiVv] [posname] archive file...


/usr/xpg4/bin/ar -p [-sVv] archive [file]...


/usr/xpg4/bin/ar -q [-cVv] archive file...


/usr/xpg4/bin/ar -r [-abciuVv] [posname] archive file...


/usr/xpg4/bin/ar -t [-sVv] archive [file]...


/usr/xpg4/bin/ar -x [-CsTVv] archive [file]...


DESCRIPTION


The ar utility maintains groups of files combined into a single archive
file. Its main use is to create and update library files. However, it can
be used for any similar purpose. The magic string and the file headers
used by ar consist of printable ASCII characters. If an archive is
composed of printable files, the entire archive is printable.


When ar creates an archive, it creates headers in a format that is
portable across all machines. The portable archive format and structure
are described in detail in ar.h(3HEAD). The archive symbol table
described there is used by the link editor ld(1) to effect multiple
passes over libraries of object files in an efficient manner. An archive
symbol table is only created and maintained by ar when there is at least
one object file in the archive. The archive symbol table is in a
specially named file that is always the first file in the archive. This
file is never mentioned or accessible to the user. Whenever the ar
command is used to create or update the contents of such an archive, the
symbol table is rebuilt. The -s option described below forces the symbol
table to be rebuilt.

OPTIONS


The following options are supported:

-a
Positions new files in archive after the file named by the posname
operand.


-b
Positions new files in archive before the file named by the posname
operand.


-c
Suppresses the diagnostic message that is written to standard error
by default when archive is created.


-C
Prevents extracted files from replacing like-named files in the
file system. This option is useful when -T is also used to prevent
truncated file names from replacing files with the same prefix.


-d
Deletes one or more files from archive.


-i
Positions new files in archive before the file named by the posname
operand. This option is quivalent to -b.


-m
Moves files. If -a, -b, or -i with the posname operand are
specified, the -m option moves files to the new position.
Otherwise, -m moves files to the end of archive.


-p
Prints the contents of files in archive to standard output. If no
files are specified, the contents of all files in archive are
written in the order of the archive.


-q
Quickly appends files to the end of archive. Positioning options
-a, -b, and -i are invalid. The command does not check whether the
added files are already in archive. This option is useful to avoid
quadratic behavior when creating a large archive piece-by-piece.


-r
Replaces or adds files in archive. If archive does not exist, a new
archive file is created and a diagnostic message is written to
standard error, unless the -c option is specified. If no files are
specified and the archive exists, the results are undefined. Files
that replace existing files do not change the order of the archive.
If the -u option is used with the -r option, only those files with
dates of modification later than the archive files are replaced. If
the -a, -b, or -i option is used, the posname argument must be
present and specifies that new files are to be placed after (-a) or
before (-b or -i) posname. Otherwise, the new files are placed at
the end.


-s
Forces the regeneration of the archive symbol table even if ar is
not invoked with an option that will modify the archive contents.
This command is useful to restore the archive symbol table after
the strip(1) command has been used on the archive.


-t
Prints a table of contents of archive. The files specified by the
file operands are included in the written list. If no file operands
are specified, all files in archive are included in the order of
the archive.


-T
Allows file name truncation of extracted files whose archive names
are longer than the file system can support. By default, extracting
a file with a name that is too long is an error. In that case, a
diagnostic message is written and the file is not extracted.


-u
Updates older files. When used with the -r option, files within
archive are replaced only if the corresponding file has a
modification time that is at least as new as the modification time
of the file within archive.


-v
Gives verbose output. When used with options -d, -r, or -x, the -v
option writes a detailed file-by-file description of the archive
creation and the constituent files, and maintenance activity. When
used with -p, -v writes the name of the file to the standard output
before writing the file itself to the standard output. When used
with -t, -v includes a long listing of information about the files
within the archive. When used with -x, -v prints the filename
preceding each extraction. When writing to an archive, -v writes a
message to the standard error.


-V
Prints its version number on standard error.


/usr/xpg4/bin/ar
The following options are supported for /usr/xpg4/bin/ar:

-v
Same as the /usr/bin/ar version, except when writing to an archive,
no message is written to the standard error.


-x
Extracts the files named by the file operands from archive. The
contents of archive are not changed. If no file operands are given,
all files in archive are extracted. If the file name of a file
extracted from archive is longer than that supported in the
directory to which it is being extracted, the results are
undefined. The modification time of each file extracted is set to
the time file is extracted from archive.


OPERANDS


The following operands are supported:

archive
A path name of the archive file.


file
A path name. Only the last component is used when comparing
against the names of files in the archive. If two or more file
operands have the same last path name component (see
basename(1)), the results are unspecified. The
implementation's archive format will not truncate valid file
names of files added to or replaced in the archive.


posname
The name of a file in the archive file, used for relative
positioning. See options -m and -r.


ENVIRONMENT VARIABLES


See environ(5) for descriptions of the following environment variables
that affect the execution of ar: LANG, LC_ALL, LC_CTYPE, LC_MESSAGES,
LC_TIME, and NLSPATH.

TMPDIR
Determine the pathname that overrides the default directory for
temporary files, if any.


TZ
Determine the timezone used to calculate date and time strings
written by ar -tv. If TZ is unset or null, an unspecified
default timezone is used.


EXIT STATUS


The following exit values are returned:

0
Successful completion.


>0
An error occurred.


ATTRIBUTES


See attributes(5) for descriptions of the following attributes:

/usr/bin/ar

+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Committed |
+--------------------+-----------------+

/usr/xpg4/bin/ar

+--------------------+-------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------+
|Interface Stability | Committed |
+--------------------+-------------------+
|Standard | See standards(5). |
+--------------------+-------------------+

SEE ALSO


basename(1), cpio(1), ld(1), lorder(1), strip(1), tar(1), ar.h(3HEAD),
a.out(4), attributes(5), environ(5), standards(5)

NOTES


If the same file is mentioned twice in an argument list, it may be put in
the archive twice.


By convention, archives are suffixed with ".a".


When inserting ELF objects into an archive file, ar might add "\n"
characters to pad these objects to an 8-byte boundary. Such padding
improves the efficiency with which ld(1) can access the archive. Only ELF
object files are padded in this way. Other archive members are not
altered. When an object with such padding is extracted from an archive,
the padding is not included in the resulting output.


September 10, 2013 AR(1)