Tribblix: manual page: ar.1

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 [-csVv] archive file...

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

/usr/bin/ar -s [-Vv] archive

/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 equivalent 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(7) 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

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.

January 23, 2022 AR(1)