comb(1)                                                   comb(1)



NAME
     comb - combines SCCS deltas

SYNOPSIS
     comb [-clist] [-o] [-psid] [-s] file...

ARGUMENTS
     -clist
          Specifies a list (see get(1) for the syntax of a list)
          of deltas to be preserved.  All other deltas are
          discarded.

     file Specifies the SCCS file that will be reconstructed.  If
          a name of - is given, the standard input is read; each
          line of the input is taken to be the name of an SCCS
          file to be processed; non-SCCS files and unreadable
          files are silently ignored.

     -o   Causes the reconstructed file to be accessed at the
          release of the delta to be created for each get -e
          generated; otherwise, the reconstructed file would be
          accessed at the most recent ancestor (see ``SCCS
          Reference'' in A/UX Programming Languages and Tools,
          Volume 2).  Use of this option may decrease the size of
          the reconstructed SCCS file.  It may also alter the
          shape of the delta tree of the original file.

     -psid
          Specifies the SCCS Identification string (SID) of the
          oldest delta to be preserved.  All older deltas are
          discarded in the reconstructed file.

     -s   Causes comb to generate a shell script that, when run,
          will produce a report giving, for each file: the
          filename, size (in blocks) after combining, original
          size (also in blocks), and percentage change computed
          by:

             100 * (original - combined) / original

          It is recommended that before any SCCS files are
          actually combined, one should use this option to
          determine exactly how much space is saved by the
          combining process.

DESCRIPTION
     comb generates a shell script (see sh(1)) that, when run,
     will reconstruct the given SCCS files by combining some
     series of changes.  Then the reconstructed files will,
     hopefully, be smaller than the original files.  The
     arguments may be specified in any order, but all keyletter
     arguments apply to all named SCCS files.  If a directory is



January 1992                                                    1

comb(1)                                                   comb(1)



     named, comb behaves as though each file in the directory
     were specified as a named file, except that non-SCCS files
     (last component of the pathname does not begin with s.) and
     unreadable files are silently ignored.

     The generated shell procedure is written on the standard
     output.

     If no arguments are specified, comb will preserve only leaf
     deltas and the minimal number of ancestors needed to
     preserve the tree.

EXAMPLES
     The command:

        comb s.file1 > tmp1

     produces a shell script saved in tmp1 that will remove from
     the SCCS-format file, s.file1, all deltas previous to the
     last set of changes, i.e., removes the capability to return
     to earlier versions.

STATUS MESSAGES AND VALUES
     Use help for explanations.

LIMITATIONS
     The comb command may rearrange the shape of the tree of
     deltas.  It may not save any space; in fact, it is possible
     for the reconstructed file actually to be larger than the
     original.

FILES
     /usr/bin/comb
          Executable file
     s.COMB
          Reconstructed SCCS file
     comb???
          Temporary file

SEE ALSO
     admin(1), delta(1), get(1), help(1), prs(1), sh(1)

     sccsfile(4) in A/UX Programmer's Reference

     ``SCCS Reference'' in A/UX Programming Languages and Tools,
     Volume 2









2                                                    January 1992