swig/Lib/ruby/progargcargv.i

/*
int PROG_ARGC
char **PROG_ARGV

    Some C function receive argc and argv from C main function.
    This typemap provides ignore typemap which pass Ruby ARGV contents
    as argc and argv to C function.
*/



// argc and argv
%typemap(in,numinputs=0) int PROG_ARGC {
    $1 = RARRAY(rb_argv)->len + 1;
}

%typemap(in,numinputs=0) char **PROG_ARGV {
    int i, n;
    VALUE ary = rb_eval_string("[$0] + ARGV");
    n = RARRAY(ary)->len;
    $1 = (char **)malloc(n + 1);
    for (i = 0; i < n; i++) {
	VALUE v = rb_obj_as_string(RARRAY(ary)->ptr[i]);
	$1[i] = (char *)malloc(RSTRING(v)->len + 1);
	strcpy($1[i], RSTRING(v)->ptr);
    }
}

%typemap(freearg) char **PROG_ARGV {
    int i, n = RARRAY(rb_argv)->len + 1;
    for (i = 0; i < n; i++) free($1[i]);
    free($1);
}