11/3/71                                               ARCHIVE (V)

NAME            archive (library) file format

SYNOPSIS        --

DESCRIPTION     The archive command ar is used to combine several

                files into one.  Its use has three benefits: when

                files are combined, the file space consumed by

                the breakage at the end of each file (256 bytes

                on the average) is saved; directories are smaller

                and less confusing; archive files of object pro-

                grams may be searched as libraries by the loader


                A file produced by ar has a "magic number" at the

                start, followed by the constituent files, each

                preceded by a file header.  The magic number is

                -147(10), or 177555(8) (it was chosen to be un-

                likely to occur anywhere else).  The header of

                each file is 16 bytes long:


                     file name, null padded on the right


                     Modification time of the file


                     User ID of file owner


                     file mode


                     file size

                If the file is an odd number of bytes long, it is

                padded with a null byte, but the size in the

                header is correct.

                Notice there is no provision for empty areas in

                an archive file.

FILES           --

SEE ALSO        ar, ld


BUGS            --

OWNER           ken, dmr