ar(4)

NAME
     ar - Archive (library) file format

SYNOPSIS
     #include <ar.h>

IMPLEMENTATION
     IRIX systems

DESCRIPTION
     The archive command, ar, combines several files into one.  Archives
     are used mainly as libraries to be searched by the link-editor, ld.

     A file produced by ar has a magic string at the start, followed by the
     constituent files, each preceded by a file header.  The magic number
     and header layout as described in the include file are:

          #define ARMAG  "!<arch>0
          #define SARMAG 8
          #define ARFMAG "`0

          struct ar_hdr
          {
               char ar_name[16];
               char ar_date[12];
               char ar_uid[6];
               char ar_gid[6];
               char ar_mode[8];
               char ar_size[10];
               char ar_fmag[2];
          };
          typedef struct ar_hdr ARHDR;

     The name is terminated with a "/" character by default.  Any remaining
     room in the name field is blank_filled.

     File name length is not limited.  For additional details, see the
     System V ABI MIPS Processor Supplement and the ar(1) man page.

     The ar_fmag field contains ARFMAG to help verify the presence of a
     header.  The other fields are left-adjusted, blank-padded numbers.
     They are decimal except for ar_mode, which is octal.  The date is the
     modification date of the file at the time of its insertion into the
     archive.

     Each file begins on an even (0 mod 2) boundary.  With compiler
     releases 7.0 and lower, a new-line is inserted between files, if
     necessary.  The size given reflects the actual size of the file
     exclusive of padding.  With compiler releases 7.1 and higher, in order
     to guarantee that each ELF format file is 16-byte aligned in the
     archive, additional padding has been added to the end of each file
     using the character '\0'.  This enables the loader (ld) to have faster
     access to members in the archive while performing static linking.
     This results in the change of size of files permanently, normally
     increased by 1 to 15 bytes.  With non-ELF files, this padding would
     not occur.

     There is no provision for empty areas in an archive file.

     The encoding of the header is portable across machines.  If an archive
     contains printable files, the archive itself is printable.

SEE ALSO
     ar(1), ld(1), nm(1)

     System V Application Binary Interface, ISBN 0-13-877598-2, Prentice
     Hall

     System V ABI MIPS Processor Supplement, ISBN 0-13-880170-3, Prentice
     Hall

     This man page is available only online.