06/10/80  ioa_ Control Strings

  Calls to the ioa_ subroutine and to the format_line command/active function
require a control_string argument. This is a character string consisting of
text to be copied and ioa_ control codes. Control codes are always identified
by a leading circumflex character (^). Control codes are replaced by strings
of literal characters and by values of later arguments to ioa_ or format_line.


List of control codes:
(The letters N, M, and D stand for integers and specify field length.
 Any of these integers can be replaced by the control string ^v, which
 takes the value of the corresponding argument to ioa_.)

^d
^Nd
   replaced by a character string representation of the corresponding numeric
   argument. If N is specified, padded with leading spaces to a length of
   N characters. Negative numbers have a leading minus sign.
^i
^Ni
   the same as ^d, for compatibility with FORTRAN and PL/I formats.


^f
^Nf
^N.Df
^.Df
   replaced by the character string representation of the corresponding
   floating-point argument. If N is specified, padded with leading spaces.
   If D is specified, rounded to D digits after the decimal point.
^e
^Ne
   edits the corresponding numeric argument, or character string representing
   a number, in floating-point exponential format:  {-}n.ddddePnn  where P is
   + or -. Full precision is shown. If N is specified, padded on the right.


^o
^No
   edits the corresponding fixed-point binary unscaled argument in octal.
   Format is the same as for ^d.
^w
^Nw
   edits the first machine word of the corresponding argument in octal, with
   leading zeros shown. If N is omitted, 12 is assumed. If N>12, padded with
   leading spaces. If N<12, first 12-N zero digits are suppressed.
^a
^Na
   edits the corresponding character string argument in ASCII, ignoring
   trailing spaces. If N is specified, padded with trailing spaces.


^b
^Nb
^N.Db
^.Db
   converts the corresponding bit-string argument to character form.
   D is the byte size in bits (0<D<5). The default for D is one.
   D=1 outputs the string in binary, D=2 in quarternary (base 4), D=3 in octal,
   D=4 in hexadecimal. If N is specified, truncated on the right or padded on
   the right with spaces.
^A
   edits an acc string (ALM ASCII with count) pointed to by the corresponding
   pointer argument. Trailing spaces are not omitted.


^p
^Np
   edits the corresponding pointer, entry variable, or label variable argument
   as:  sss|ooo(bb)  where sss = segment number, ooo = octal offset, and
   bb = decimal bit offset. If N is specified, padded on the right with spaces.
^|
^N|
   is replaced by one or N formfeed characters.
^/
^N/
   is replaced by one or N newline characters.
^-
^N-
   is replaced by one or N horizontal tab characters.


^x
^Nx
   is replaced by one or N space characters.
^^
^N^
   is replaced by one or N circumflex characters.
^s
^Ns
   ignores the corresponding argument, or N arguments.
^(
^N(
   starts an iteration loop, ended by a corresponding ^). If N is specified,
   repeats the loop N times. Otherwise, repeats it until the argument list is
   exhausted. Iterations can be nested up to four deep.


^)
   see "^(" directly above.
^[
   starts an if/then/else or case selection group, ended by the matching ^]
   and divided internally into clauses by occurrences of ^; control codes.
   If the corresponding argument is a fixed binary number N, the Nth clause
   is expanded as the next portion of the control string. If the corresponding
   argument is a nonzero bit string, the first clause is expanded. If it is
   an all-zero bit string, the second clause is expanded, or the control string
   is omitted if there is no second clause. The arguments "true" and "false"
   are equivalent to "1"b and "0"b. Nesting can be up to four deep.
^]
   see "^[" directly above.


^;
^N;
   delimit clauses inside ^[ ^] groups. The ^N; control code is equivalent
   to N repetitions of ^;.
^Nt
^N.Mt
   inserts enough space characters to reach column N. If M is specified, it
   is the minimum number of spaces to be placed in the output string.


Notes:
  When no field width is specified, a field size is used that is large enough
to contain the edited data. If the field size specified is too small, it is
ignored in favor of a large enough field size.

An invalid control code, an isolated circumflex character (^), or a control
code requiring an argument when there are no more arguments left, is inserted
unchanged into the edited line.

A control code whose type does not match the type of the corresponding
argument is replaced by a string of asterisks.

If an argument corresponding to a control code is an array (ioa_ subroutine
case), elements of the array are taken to match successive control codes.
When the array is exhausted, the next argument is processed. Arrays are scanned
in row major order.


Examples: For examples, see the MPM Subroutines manual.


                                          -----------------------------------------------------------


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. .

                                          -----------------------------------------------------------

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