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ar (1g)


ar - create, modify, and extract from archives


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


GNU Development Tools                                       AR(1)

     ar - create, modify, and extract from archives

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

     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.

     GNU ar can maintain archives whose members have names of any
     length; however, depending on how ar is configured on your
     system, a limit on member-name length may be imposed for
     compatibility with archive formats maintained with other
     tools.  If it exists, the limit is often 15 characters
     (typical of formats related to a.out) or 16 characters
     (typical of formats related to coff).

     ar is considered a binary utility because archives of this
     sort are most often used as libraries holding commonly
     needed subroutines.

     ar creates an index to the symbols defined in relocatable
     object modules in the archive when you specify the modifier
     s.  Once created, this index is updated in the archive
     whenever ar makes a change to its contents (save for the q
     update operation).  An archive with such an index speeds up
     linking to the library, and allows routines in the library
     to call each other without regard to their placement in the

     You may use nm -s or nm --print-armap to list this index
     table.  If an archive lacks the table, another form of ar
     called ranlib can be used to add just the table.

     GNU ar can optionally create a thin archive, which contains
     a symbol index and references to the original copies of the
     member files of the archives.  Such an archive is useful for
     building libraries for use within a local build, where the
     relocatable objects are expected to remain available, and
     copying the contents of each object would only waste time
     and space.  Thin archives are also flattened, so that adding
     one or more archives to a thin archive will add the elements
     of the nested archive individually.  The paths to the

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GNU Development Tools                                       AR(1)

     elements of the archive are stored relative to the archive

     GNU ar is designed to be compatible with two different
     facilities.  You can control its activity using command-line
     options, like the different varieties of ar on Unix systems;
     or, if you specify the single command-line option -M, you
     can control it with a script supplied via standard input,
     like the MRI "librarian" program.

     GNU ar allows you to mix the operation code p and modifier
     flags mod in any order, within the first command-line

     If you wish, you may begin the first command-line argument
     with a dash.

     The p keyletter specifies what operation to execute; it may
     be any of the following, but you must specify only one of

     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;

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GNU Development Tools                                       AR(1)

         new members are always placed at the end of the archive.

         The modifier v makes ar list each file as it is

         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 i to
         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.

     s   Add an index to the archive, or update it if it already
         exists.  Note this command is an exception to the rule
         that there can only be one command letter, as it is
         possible to use it as either a command or a modifier.
         In either case it does the same thing.

     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.

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GNU Development Tools                                       AR(1)

     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.

         Displays the list of command line options supported by
         ar and then exits.

         Displays the version information of ar and then exits.

     A number of modifiers (mod) may immediately follow the p
     keyletter, to specify variations on an operation's behavior:

     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.

         If binutils was configured with
         --enable-deterministic-archives, then this mode is on by
         default.  It can be disabled with the U modifier, below.

     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.

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GNU Development Tools                                       AR(1)

     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

     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

     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 can not be used with the linker.  In
         order to build a symbol table, you must omit the S
         modifier 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

     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.

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GNU Development Tools                                       AR(1)

     U   Do not operate in deterministic mode.  This is the
         inverse of the D modifier, above: added files and the
         archive index will get their actual UID, GID, timestamp,
         and file mode values.

         This is the default unless binutils was configured with

     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 toolchain has
     been built with plugin support enabled.

     The optional command line switch --target bfdname specifies
     that the archive members are in an object code format
     different from your system's default format.  See

         Read command-line options from file.  The options read
         are inserted in place of the original @file option.  If
         file does not exist, or cannot be read, then the option
         will be treated literally, and not removed.

         Options in file are separated by whitespace.  A
         whitespace character may be included in an option by
         surrounding the entire option in either single or double
         quotes.  Any character (including a backslash) may be
         included by prefixing the character to be included with
         a backslash.  The file may itself contain additional
         @file options; any such options will be processed

     See attributes(5) for descriptions of the following

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GNU Development Tools                                       AR(1)

     |Availability   | developer/gnu-binutils |
     |Stability      | Uncommitted            |
     nm(1), ranlib(1), and the Info entries for binutils.

     Copyright (c) 1991, 1992, 1993, 1994, 1995, 1996, 1997,
     1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
     2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.

     Permission is granted to copy, distribute and/or modify this
     document under the terms of the GNU Free Documentation
     License, Version 1.3 or any later version published by the
     Free Software Foundation; with no Invariant Sections, with
     no Front-Cover Texts, and with no Back-Cover Texts.  A copy
     of the license is included in the section entitled "GNU Free
     Documentation License".

     This software was built from source available at  The original
     community source was downloaded from

     Further information about this software can be found on the
     open source community website at

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