Computer Science


ar(1)                 GNU Development Tools                 ar(1)

NAME
       ar - create, modify, and extract from archives.

SYNOPSIS
       ar [-]{dmpqrtx}[abcilosSuvV] [membername] archive files...

DESCRIPTION
       The GNU ar program creates, modifies,  and  extracts  from
       archives.   An  archive is a single file holding a collec-
       tion 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),  times-
       tamp,  owner,  and group are preserved in the archive, and
       may be reconstituted 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 charac-
       ters  (typical  of formats related to a.out) or 16 charac-
       ters (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 will create an index to the symbols defined in relocat-
       able  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 rou-
       tines 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 in-
       dex table.  If an archive lacks the table, another form of
       ar called ranlib can be used to add just the table.

       ar  insists  on  at  least  two  arguments to execute: one
       keyletter specifying the operation (optionally accompanied
       by other keyletters specifying modifiers), and the archive
       name to act on.

       Most operations can also accept further  files  arguments,
       specifying particular files to operate on.

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

       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 files; the archive is
              untouched if you specify no files to delete.

              If you specify the `v' modifier, ar will list  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 li-
              brary, if a symbol is defined in more than one mem-
              ber.

              If no modifiers are used with m,  any  members  you
              name in the files arguments are moved to the end of
              the archive; you can use the `a', `b', or `i' modi-
              fiers 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 spec-
              ified, show the member name before copying its con-
              tents to standard output.

              If you specify no  files,  all  the  files  in  the
              archive are printed.

       q      Quick  append;  add  files  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 files 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 files doesn't exist,
              ar displays an error  message,  and  leaves  undis-
              turbed 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.

       t      Display a table listing the contents of archive, or
              those of the files listed in files that are present
              in  the  archive.  Normally only the member name is
              shown; if you also want to see the  modes  (permis-
              sions),  timestamp, owner, group, and size, you can
              request that by also specifying the `v' modifier.

              If you do not specify any files, 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' will list 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  files)  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 any files, all files  in  the
              archive are extracted.

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

       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 mem-
              bername 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 mem-
              bername argument, before the archive specification.
              (same as `i').

       c      Create  the  archive.  The specified archive is al-
              ways created if it didn't 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.  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 mem-
              bername argument, before the archive specification.
              (same as `b').

       l      This modifier is accepted but not used.

       o      Preserve the original dates  of  members  when  ex-
              tracting  them.  If you do not specify this modifi-
              er,  files  extracted  from  the  archive  will  be
              stamped with the time of extraction.

       s      Write an object-file index into the archive, or up-
              date 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 in-
              formation, such as filenames  processed,  when  the
              modifier `v' is appended.

       V      This modifier shows the version number of ar.

SEE ALSO
       `binutils' entry in info; The GNU Binary Utilities, Roland
       H. Pesch (October 1991).  nm(1), ranlib(1).

COPYING
       Copyright (c) 1991 Free Software Foundation, Inc.

       Permission is granted  to  make  and  distribute  verbatim
       copies  of  this  manual provided the copyright notice and
       this permission notice are preserved on all copies.

       Permission is granted to copy and distribute modified ver-
       sions  of  this  manual  under the conditions for verbatim
       copying, provided that the entire resulting  derived  work
       is  distributed  under  the  terms  of a permission notice
       identical to this one.

       Permission is granted to copy and distribute  translations
       of this manual into another language, under the above con-
       ditions for modified versions, except that this permission
       notice  may  be  included  in translations approved by the
       Free Software Foundation instead of in  the  original  En-
       glish.

cygnus support           5 November 1991                        1

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