COMMAREA instructs MFX to provide an area for communication between exit programs. The size of this area is given as a decimal number n of bytes; x, a character string at most n bytes long, designates the initial value to be stored in this area. Regardless of the value of n, which may be between 1 and 256, x may not exceed 89 bytes in length. (Whenever x has fewer than n characters, it will be right-padded with blanks to a length of n.) If COMMAREA is specified via the EXEC statement, blanks may be included within the string x. However, if COMMAREA is specified via the $ORTPARM DD statement, intervening blanks are not allowed. In neither case is a right parenthesis permitted since it delimits the COMMAREA parameter.
Both n and x are optional. If either subparameter is specified, it will determine the other: n defaults to the length of x, x defaults to n blanks. If neither x nor n is specified, n defaults to 80 bytes, x to 80 blanks.
NOCOMMAREA is the program default: no area for communication between exit programs is provided, although exit routines may still use the 19th word of the save area.
Exit program access to this communication area is described in the discussion of exit programs, see The Exit Communication Area.
COMMAREA does not apply to exits called using the 64-bit parameter list.
