AR(5)                   GENIX Programmer's Manual                   AR(5)



      NAME
           ar - archive (library) file format

      SYNOPSIS
           # include <ar.h>

      DESCRIPTION
           The archive command ar is used to combine 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:

                /*
                 * ar.h:
                 */

                # define ARMAG  "!<arch>\n"
                # define SARMAG 8

                # define ARFMAG "`\n"

                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];
                };

           The name is a blank-padded string.  The ar_fmag field contains  ARF-
           MAG  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;  a  new-line  is
           inserted  between  files if necessary.  Nevertheless, the size given
           reflects the actual size of the file exclusive of padding.

           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)




      Printed 11/16/83                                                        1

      AR(5)                   GENIX Programmer's Manual                   AR(5)



      BUGS
           File  names  lose  trailing  blanks.   Most  software  dealing  with
           archives takes even an included blank as a name terminator.




















































      Printed 11/16/83                                                        2