02/06/84  parse_file_

The parse_file_ subroutine provides a facility for parsing ASCII text
into symbols and break characters.  It is recommended for occasionally
used text-scanning applications.  In applications where speed or
frequent use are important, in-line PL/I code is recommended (to do
parsing) instead.


A restriction of the subroutine is that the text to be parsed must be
an aligned character string.

The initialization entry points, parse_file_$parse_file_init_name and
parse_file_$parse_file_init_ptr, save a pointer to the text to be
scanned and a character count in internal static storage.  Thus, only
one text can be parsed at one time.


Entry points in parse_file_:
   (List is generated by the help command)


:Entry:  parse_file_: 02/06/84 parse_file_

Function: scans the text file and returns the next break character or
symbol.  Blanks, newline characters, and comments enclosed by /* and
*/, however, are skipped.


Syntax:
declare parse_file_ entry (fixed bin, fixed bin, fixed bin(1),
     fixed bin(1));
call parse_file_ (ci, cc, break, eof);


Arguments:
ci
   is an index to the first character of the symbol or break character.
   (Output).  (The first character of the text is considered to be
   character 1.)
cc
   is the number of characters in the symbol.  (Output)
break
   is set to 1 if the returned item is a break character; otherwise, it
   is 0.  (Output)
eof
   is set to 1 if the end of text has been reached; otherwise, it is 0.
   (Output)


:Entry:  parse_file_cur_line:  02/06/84 parse_file_$parse_file_cur_line


Function: returns to the caller the current line of text being
scanned.  This entry is useful in printing diagnostic error messages.


Syntax:
declare parse_file_$parse_file_cur_line entry (fixed bin, fixed bin);
call parse_file_$parse_file_cur_line (ci, cc);


Arguments:
ci
   is an index to the first character of the line.  (Output).  (The
   first character of the text is considered to be character 1.)
cc
   is the number of characters in the line.  (Output)


:Entry:  parse_file_init_name:
02/06/84 parse_file_$parse_file_init_name


Function: initializes the subroutine given a directory and an entry
point name.  It gets a pointer to the desired segment and saves it for
subsequent calls in internal static.


Syntax:
declare parse_file_$parse_file_init_name entry (char(*), char(*), ptr,
     fixed bin(35));
call parse_file_$parse_file_init_name (dir_name, entryname, ptr, code);


Arguments:
dir_name
   is the directory name portion of the pathname of the segment to be
   parsed.  (Input)
entryname
   is the entryname of the segment to be parsed.  (Input)
ptr
   is a pointer to the segment.  (Output)
code
   is a standard status code.  (Output).  It is zero if the segment is
   initiated.  If nonzero, the segment cannot be initiated.  It can
   return any code from hcs_$initiate except error_table_$segknown.


:Entry:  parse_file_init_ptr:  02/06/84 parse_file_$parse_file_init_ptr


Function: initializes the parse_file_ subroutine with a supplied
pointer and character count.  It is used in cases where a pointer to
the segment to be parsed is already available.


Syntax:
declare parse_file_$parse_file_init_ptr entry (ptr, fixed bin);
call parse_file_$parse_file_init_ptr (ptr, cc);


Arguments:
ptr
   is a pointer to a segment or an aligned character string.  (Input)
cc
   is the character count of the ASCII text to be scanned.  (Input)


:Entry:  parse_file_ptr:  02/06/84 parse_file_$parse_file_ptr


Function: This entry point is identical to the parse_file_ entry point
except that a pointer (with bit offset) to the break character or the
symbol is returned instead of a character index.


Syntax:
declare parse_file_$parse_file_ptr entry (ptr, fixed bin, fixed bin(1),
     fixed bin(1));
call parse_file_$parse_file_ptr (ptr, cc, break, eof);


Arguments:
ptr
   is a pointer to the symbol or the break character.  (Output)
cc
   is the number of characters in the symbol.  (Output)
break
   is set to 1 if the returned item is a break character; otherwise, it
   is 0.  (Output)
eof
   is set to 1 if the end of text has been reached; otherwise, it is 0.
   (Output)


:Entry:  parse_file_line_no:  02/06/84 parse_file_$parse_file_line_no


Function: returns to the caller the current line number of text being
scanned.  This entry is useful in printing diagnostic error messages.


Syntax:
declare parse_file_$parse_file_line_no entry (fixed bin);
call parse_file_$parse_file_line_no (cl);


Arguments:
cl
   is the number of the current line.  (Output)


:Entry:  parse_file_set_break:
02/06/84 parse_file_$parse_file_set_break


Function: is used to define break characters.  Normally, all
nonalphanumeric characters are break characters (including blank and
newline).


Syntax:
declare parse_file_$parse_file_set_break entry (char(*));
call parse_file_$parse_file_set_break (cs)


Arguments:
cs
   is a control string.  (Input).  Each character found in cs is made a
   break character.


:Entry:  parse_file_unset_break:
02/06/84 parse_file_$parse_file_unset_break


Function: renders break characters as normal alphanumeric characters.
It is not possible to unset blank, newline, or comment delimiters,
however.  These are always treated as break characters.


Syntax:
declare parse_file_$parse_file_unset_break entry (char(*));
call parse_file_$parse_file_unset_break (cs);


Arguments:
cs
   is a control string, each character of which is made a nonbreaking
   character.  (Input)


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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