02/05/86  create_dm_file

Syntax as a command:  create_dm_file path {-control_args}


Function: creates an unpopulated data management (DM) file for use
with Multics data management (see the Programmer's Reference Manual).
Files created in this manner would be used primarily for test purposes
or in applications calling the file_manager_ subroutine directly.


Arguments:
path
   is the pathname of the DM file to be created.


Control arguments:
-concurrency, -conc
   provides automatic concurrent access protection to a protected DM
   file by enforcing locking conventions on get and put operations to
   the file (see "Notes").  (Default)
-no_concurrency, -nconc
   turns concurrency protection off for a protected DM file, saving on
   overhead when locking is unnecessary (see "Notes").
-no_rollback, -nrlb
   turns the rollback capability off for a protected DM file, saving on
   overhead when rollback is unnecessary (see "Notes").


-protected, -prot
   creates a protected DM file, which means the file is entitled to the
   protection features provided by the integrity services of data
   management.  You can access a protected DM file only within the
   context of a transaction.  (See "Notes.") (Default)
-ring_brackets W {R}, -rb W {R}
   sets the write ring bracket to W and the read ring bracket to R.  If
   you don't specify the read ring bracket, it defaults to the value
   given for the write ring bracket.  Both R and W must be greater
   than, or equal to, your validation level.


-rollback, -rlb
   provides an automatic rollback capability for a protected DM file,
   by logging before images of modifications made to the file.  These
   images are used in the event of transaction, process, or system
   failure to restore the file to its original state.  (See "Notes.")
   (Default)
-unprotected, -unprot, -not_protected, -nprot
   creates an unprotected DM file, without the benefit of integrity
   services.  You can access an unprotected DM file outside a
   transaction.  (See "Notes.")


Access required: You need sma access on the directory in which the DM
file is created and s access on the directory containing that
directory.


Notes: The -unprotected control argument is mutually exclusive with
-concurrency, -no_concurrency, -no_rollback, -protected, and -rollback.
If you use two mutually exclusive control arguments, the rightmost
option in the command line takes precedence.

This command is part of the command level interface to Multics data
management.


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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