Man Linux: Main Page and Category List


       ar - create, modify, and extract from archives


       ar [-X32_64] [-]p[mod [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 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,  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

       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

       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.

       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.

       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.


       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 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 1.1 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’’.