NAME

       ar - create, modify, and extract from archives

SYNOPSIS

       ar [-X32_64] [-]p[mod] [--plugin name] [--target bfdname] [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.

       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 archive.

       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.

OPTIONS

       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 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, 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 end.

       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.

       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.

       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
           --enable-deterministic-archives.

       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.

       The ar program also supports some command line options which are neither modifiers nor
       actions, but which do change its behaviour in specific ways:

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

       --version
           Displays the version information of ar and then exits.

       -X32_64
           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.

       --plugin name
           The optional command line switch --plugin name causes ar to load the plugin called
           name which adds support for more file formats, including object files with link-time
           optimization information.

           This option is only available if the toolchain has been built with plugin support
           enabled.

           If --plugin is not provided, but plugin support has been enabled then ar iterates over
           the files in ${libdir}/bfd-plugins in alphabetic order and the first plugin that
           claims the object in question is used.

           Please note that this plugin search directory is not the one used by ld's -plugin
           option.  In order to make ar use the  linker plugin it must be copied into the
           ${libdir}/bfd-plugins directory.  For GCC based compilations the linker plugin is
           called liblto_plugin.so.0.0.0.  For Clang based compilations it is called LLVMgold.so.
           The GCC plugin is always backwards compatible with earlier versions, so it is
           sufficient to just copy the newest one.

       --target target
           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

       @file
           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 recursively.

SEE ALSO

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

COPYRIGHT

       Copyright (c) 1991-2018 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".