ar - create, modify, and extract from archives


   ar [-X32_64] [-]p[mod] [--plugin name] [--target bfdname] [relpos]
   [count] 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
   archive.  This is useful for building libraries for use within a local
   build tree, where the relocatable objects are expected to remain
   available, and copying the contents of each object would only waste
   time and space.

   An archive can either be thin or it can be normal.  It cannot be both
   at the same time.  Once an archive is created its format cannot be
   changed without first deleting it and then creating a new archive in
   its place.

   Thin archives are also flattened, so that adding one thin archive to
   another thin archive does not nest it, as would happen with a normal
   archive.  Instead the elements of the first archive are added
   individually to the second archive.

   The paths to the elements of the archive are stored relative to the
   archive itself.

   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 argument.

   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 them:

   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

   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, implementations of ar
       have the option of not updating the archive's symbol table if one
       exists.  Too many different systems however assume that symbol
       tables are always up-to-date, so GNU ar will rebuild the table even
       with a quick append.

       Note - GNU ar treats the command qs as a synonym for r - replacing
       already existing files in the archive and appending new ones at the

   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

   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

       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

       Files cannot be extracted from a thin archive.

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

       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.

   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
       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 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.

   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

       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 recursively.


   nm(1), ranlib(1), and the Info entries for binutils.


   Copyright (c) 1991-2016 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".


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