01/19/87  compare_mst


Syntax as a command:  compare_mst master_spec copy_spec {-control_args}


Function:  reads a master Multics System Tape (MST) and a copy MST, and
lists all differences between them.  MST data can come either from a
tape or from an MST image stored in a file.


Arguments:
master_spec
   can be either -master_volume or -master_file, or the tape volume
   name identifying one of the MSTs to be compared.  The reel
   identification number, which is site dependent, can be up to 32
   characters long.
copy_spec
   can be either -copy_volume or -copy_file, or the tape volume name
   identifying the other MST to be compared.


Control arguments:
-master_volume volname, -mvol volname
   gives the master tape volume name of the MST to be compared.
-master_file path, -mf path
   gives the pathname of a file containing the master MST image to be
   compared.  This file must have been previously created by
   generate_mst or copy_mst.
-copy_volume volname, -cvol volname
   gives the copy tape volume name.
-copy_file path, -cf path
   gives the pathname of the file containing the copy MST image.


-density DEN, -den DEN
   gives a tape density.  It applies to the preceding -master_volume or
   -copy_volume control argument.  DEN may be 800, 1600 or 6250.  The
   tapes are mounted on a tape drive capable of reading density DEN.
   However, the actual density at which the input tapes are written
   determines the density used for reading.  The default density is
   1600 BPI (bits per inch).
-save
   saves the contents of corresponding segments with discrepancies in
   the user's working directory under the names tp1.<segment_name> and
   tp2.<segment_name>.  An added segment is saved under the name
   tp2.<segment_name>.


Notes:  Differences in segment headers and the starting address of any
inequalities or differing lengths of segment contents are noted.
Additions, deletions, and moves of segments are handled.  One can
optionally save the contents of differing segments in the user's
working directory for further detailed comparisons.  Any number of
collections can be handled, but a warning message is printed if a tape
does not end in a collection mark.  If the active_all_rings_data
segment is found on the first tape, a message containing the system
identifiers of both tapes is printed.


List of severity values:
   compare_mst sets an external variable to indicate the success or
   failure of copy and compare operations.  This variable may be
   examined using the severity command/active function.  For example:

      &goto RESULT_&[severity compare_mst]

   The following severity values can be returned.


0
   The compare operation completed successfully.
3
   The compare operation found discrepancies between master and copy
   tapes.
4
   The compare operation failed, due to fatal errors.  These errors are
   diagnosed in error messages.


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Historical Background

This edition of the Multics software materials and documentation is provided and donated
to Massachusetts Institute of Technology by Group BULL including BULL HN Information Systems Inc. 
as a contribution to computer science knowledge.  
This donation is made also to give evidence of the common contributions of Massachusetts Institute of Technology,
Bell Laboratories, General Electric, Honeywell Information Systems Inc., Honeywell BULL Inc., Groupe BULL
and BULL HN Information Systems Inc. to the development of this operating system. 
Multics development was initiated by Massachusetts Institute of Technology Project MAC (1963-1970),
renamed the MIT Laboratory for Computer Science and Artificial Intelligence in the mid 1970s, under the leadership
of Professor Fernando Jose Corbato. Users consider that Multics provided the best software architecture 
for managing computer hardware properly and for executing programs. Many subsequent operating systems 
incorporated Multics principles.
Multics was distributed in 1975 to 2000 by Group Bull in Europe , and in the U.S. by Bull HN Information Systems Inc., 
as successor in interest by change in name only to Honeywell Bull Inc. and Honeywell Information Systems Inc. .

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Permission to use, copy, modify, and distribute these programs and their documentation for any purpose and without
fee is hereby granted,provided that the below copyright notice and historical background appear in all copies
and that both the copyright notice and historical background and this permission notice appear in supporting
documentation, and that the names of MIT, HIS, BULL or BULL HN not be used in advertising or publicity pertaining
to distribution of the programs without specific prior written permission.
    Copyright 1972 by Massachusetts Institute of Technology and Honeywell Information Systems Inc.
    Copyright 2006 by BULL HN Information Systems Inc.
    Copyright 2006 by Bull SAS
    All Rights Reserved