The include file FIO_PAR defines symbolic names for various constants which may be required by
tasks. The most useful constants are FIO__SZMOD, which is used to specify the length of the access
mode string in calls to FIO_OPEN and RIO_OPEN, and FIO__SZFNM, which is the maximum
allowed length of a filename in FIO/RIO.
If you need to test for explicit status values returned from FIO/RIO subroutines, include the statement:
in the program. The return status can then be tested. For example:
However, there are problems to do with portability when testing return status values. These are dealt with in the next section.