#include <octave/oct.h> DEFUN_DLD (globaldemo, args, , "Global demo.") { int nargin = args.length (); octave_value retval; if (nargin != 1) print_usage (); else { std::string s = args(0).string_value (); if (! error_state) { octave_value tmp = get_global_value (s, true); if (tmp.is_defined ()) retval = tmp; else retval = "Global variable not found"; set_global_value ("a", 42.0); } } return retval; }