ar - Unix, Linux Command


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NAME

ar - create, modify and extract from archives.

SYNOPSIS

ar [--plugin name] [-X32_64] [-] p[mod [relpos] [count]] archive [member...]

DESCRIPTION

The GNU ar program creates, modifies, and extracts from archives. An archive is a single file holding a collection of other files in a structure that makes it possible to retrieve the original individual files (called members of the archive).

The original files' contents, mode (permissions), timestamp, owner, and group are preserved in the archive, and can be restored on extraction.

OPTIONS

TAG DESCRIPTION
d Delete modules from the archive. Specify the names of modules to be deleted as member...; the archive is untouched if you specify no files to delete. If you specify the v modifier, ar lists each module as it is deleted.
m Use this operation to move members in an archive. The ordering of members in an archive can make a difference in how programs are linked using the library, if a symbol is defined in more than one member.

If no modifiers are used with "m", any members you name in the member arguments are moved to the end of the archive; you can use the a, b, or i modifiers to move them to a specified place instead.

p Print the specified members of the archive, to the standard output file. If the v modifier is specified, show the member name before copying its contents to standard output. If you specify no member arguments, all the files in the archive are printed.
q Quick append; Historically, add the files member... to the end of archive, without checking for replacement. The modifiers a, b, and i do not affect this operation; new members are always placed at the end of the archive.

The modifier v makes ar list each file as it is appended.

Since the point of this operation is speed, the archive's symbol table index is not updated, even if it already existed; you can use ar s or ranlib explicitly to update the symbol table index.

However, too many different systems assume quick append rebuilds the index, so GNU ar implements q as a synonym for r.
r Insert the files member... into archive (with replacement). This operation differs from q in that any previously existing members are deleted if their names match those being added. If one of the files named in member... does not exist, ar displays an error message, and leaves undisturbed any existing members of the archive matching that name.

By default, new members are added at the end of the file; but you may use one of the modifiers a, b, or ito request placement relative to some existing member.

The modifier v used with this operation elicits a line of output for each file inserted, along with one of the letters a or r to indicate whether the file was appended (no old member deleted) or replaced.
t Display a table listing the contents of archive, or those of the files listed in member... that are present in the archive. Normally only the member name is shown; if you also want to see the modes (permissions), timestamp, owner, group, and size, you can request that by also specifying the v modifier. If you do not specify a member, all files in the archive are listed.

If there is more than one file with the same name (say, fie) in an archive (say b.a), ar t b.a fie lists only the first instance; to see them all, you must ask for a complete listing---in our example, ar t b.a.

x Extract members (named member) from the archive. You can use the v modifier with this operation, to request that ar list each name as it extracts it.

If you do not specify a member, all files in the archive are extracted.

Files cannot be extracted from a thin archive.

MODIFIERS

TAG DESCRIPTION
a Add new files after an existing member of the archive. If you use the modifier a, the name of an existing archive member must be present as the relpos argument, before the archive specification.
b Add new files before an existing member of the archive. If you use the modifier b, the name of an existing archive member must be present as the relpos argument, before the archive specification. (same as i).
c Create the archive. The specified archive is always created if it did not exist, when you request an update. But a warning is issued unless you specify in advance that you expect to create it, by using this modifier.
D Operate in deterministic mode. When adding files and the archive index use zero for UIDs, GIDs, timestamps, and use consistent file modes for all files. When this option is used, if ar is used with identical options and identical input files, multiple runs will create identical output files regardless of the input files' owners, groups, file modes, or modification times.
f Truncate names in the archive. GNU ar will normally permit file names of any length. This will cause it to create archives which are not compatible with the native ar program on some systems. If this is a concern, the f modifier may be used to truncate file names when putting them in the archive.
i Insert new files before an existing member of the archive. If you use the modifier i, the name of an existing archive member must be present as the relpos argument, before the archive specification. (same as b).
l This modifier is accepted but not used.
N Uses the count parameter. This is used if there are multiple entries in the archive with the same name. Extract or delete instance count of the given name from the archive.
o Preserve the original dates of members when extracting them. If you do not specify this modifier, files extracted from the archive are stamped with the time of extraction.
P Use the full path name when matching names in the archive. GNU ar can not create an archive with a full path name (such archives are not POSIX complaint), but other archive creators can. This option will cause GNU ar to match file names using a complete path name, which can be convenient when extracting a single file from an archive created by another tool.
s Write an object-file index into the archive, or update an existing one, even if no other change is made to the archive. You may use this modifier flag either with any operation, or alone. Running ar s on an archive is equivalent to running ranlib on it.
S Do not generate an archive symbol table. This can speed up building a large library in several steps. The resulting archive cannot be used with the linker. In order to build a symbol table, you must omit the Smodifier on the last execution of ar, or you must run ranlib on the archive.
T Make the specified archive a thin archive. If it already exists and is a regular archive, the existing members must be present in the same directory as archive.
u Normally, ar r... inserts all files listed into the archive. If you would like to insert only those of the files you list that are newer than existing members of the same names, use this modifier. The u modifier is allowed only for the operation r (replace). In particular, the combination qu is not allowed, since checking the timestamps would lose any speed advantage from the operation q.
v This modifier requests the verbose version of an operation. Many operations display additional information, such as filenames processed, when the modifier v is appended.
V This modifier shows the version number of ar. ar ignores an initial option spelt -X32_64, for compatibility with AIX . The behaviour produced by this option is the default for GNU ar. ar does not support any of the other -X options; in particular, it does not support -X32 which is the default for AIX ar.

The optional command line switch --plugin name causes ar to load the plugin called name which adds support for more file formats. This option is only available if the tool chain has been built with plugin support enabled.

EXAMPLES

Example-1:

 To create a new archive Test-AR.a containing three files example-3 example-2 example-1:

#ar -rc Test-AR.a example-3 example-2 example-1

output:
ar file Test-AR.a reated succesfully.

Example-2:

To add an archive symbol table to an existing archive Test-AR.a use:

# ar -s Test-AR.a

output:
Done succesfully without any error.

Example-3:

To delete file example-1 from archive Test-AR.a, use:

#ar -d Test-AR.a example-1

output:
Done succesfully without any error.

Example-4:

To verbosely list the contents of archive ex.a, use:

#ar -tv Test-AR.a

output:
rw-rw-r-- 1000/1000 0 Dec 29 18:36 2016 example-2
rw-rw-r-- 1000/1000 0 Dec 29 18:36 2016 example-3

Example-5:

To extract the object files available in an archive:

#ar x Test-AR.a

output:
(All the content are extracted )
-rw-rw-r-- 1 nubo nubo 0 Dec 29 18:35 example-1
-rw-rw-r-- 1 nubo nubo 0 Dec 29 18:52 example-3
-rw-rw-r-- 1 nubo nubo 0 Dec 29 18:52 example-2

Example-6:

To append  example-4 object file in the current directory:

#ar q Test-AR.a example-4

output:
Output would be successfully done without any error.

Example-7:

To Display a table listing the contents of archive

#ar t  Test-AR.a

output:
example-2
example-3
example-1
example-4

Example-8:  

To Delete modules from the archive.

Specify the names of modules to be deleted as member.

#ar d Test-AR.a

Example-9:

To Print the specified members of the archive, to the standard output file.

#ar p Test-AR.a


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