plparseopts: parse arguments for Fortran 77

When called from Fortran 77, 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 77 system routines iargc and getarg are used internally to obtain the number of arguments and argument values. (Note, during configuration, the user's Fortran 77 compiler is checked to see whether it supports iargc and getarg. If it does not, the Fortran 77 plparseopts simply writes a warning message and returns.

mode (PLINT, input) Parsing mode; see plparseopts for details.