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AR(6)                            Games Manual                            AR(6)



NAME
       ar - archive (library) file format

SYNOPSIS
       #include <&lt;ar.h>&gt;

DESCRIPTION
       The  archive  command  ar(1) is used to combine several files into one.
       Archives are used mainly as libraries to be  searched  by  the  loaders
       2l(1) et al.

       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>\n"
              #define SARMAG  8

              #define ARFMAG  "`\n"

              struct ar_hdr {
                      char    name[16];
                      char    date[12];
                      char    uid[6];
                      char    gid[6];
                      char    mode[8];
                      char    size[10];
                      char    fmag[2];
              };
              #define SAR_HDR 60

       The  name  is a blank-padded string.  The field contains to help verify
       the presence of a header.  The other fields are  left-adjusted,  blank-
       padded  numbers.  They are decimal except for which is octal.  The date
       is the modification date of the file (see stat(2)) at the time  of  its
       insertion  into  the  archive.   The mode is the low 9 bits of the file
       permission mode.  The length of the header is Because the structure  is
       padded  in an architecture-dependent manner, the structure should never
       be read or written as a unit; instead, each field  should  be  read  or
       written independently.

       Each  file  begins on an even (0 mod 2) boundary; a newline is inserted
       between files if necessary.  Nevertheless size reflects the actual size
       of the file exclusive of padding.

       When  all  members of an archive are object files of the same architec-
       ture, ar automatically adds an extra  file,  named  __.SYMDEF,  as  the
       first  member  of the archive.  This file contains an index used by the
       loaders to locate all externally defined text and data symbols  in  the
       archive.

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

SEE ALSO
       ar(1), 2l(1), nm(1), stat(2)

BUGS
       The  uid and gid fields are unused in Plan 9.  They provide compatibil-
       ity with Unix ar format.



                                                                         AR(6)