When called from Fortran, this routine has the same effect as when invoked from C (see plparseopts) except that the argument list just contains the parsing mode and the Fortran system routines iargc and getarg are used internally to obtain the number of arguments and argument values. (Note, during configuration, the user's Fortran compiler is checked to see whether it supports iargc and getarg. If it does not, the Fortran plparseopts simply writes a warning message and returns.