ole_show_help

/*
 *  call-seq:
 *     WIN32OLE.ole_show_help(obj [,helpcontext])
 * 
 *  Displays helpfile. The 1st argument specifies WIN32OLE_TYPE
 *  object or WIN32OLE_METHOD object or helpfile.
 *
 *     excel = WIN32OLE.new('Excel.Application')
 *     typeobj = excel.ole_type
 *     WIN32OLE.ole_show_help(typeobj)
 */
static VALUE
fole_s_show_help(argc, argv, self)
    int argc;
    VALUE *argv;
    VALUE self;
{
    VALUE target;
    VALUE helpcontext;
    VALUE helpfile;
    VALUE name;
    HWND  hwnd;
    rb_scan_args(argc, argv, "11", &target, &helpcontext);
    if (rb_obj_is_kind_of(target, cWIN32OLE_TYPE) ||
        rb_obj_is_kind_of(target, cWIN32OLE_METHOD)) {
        helpfile = rb_funcall(target, rb_intern("helpfile"), 0);
        if(strlen(StringValuePtr(helpfile)) == 0) {
            name = rb_ivar_get(target, rb_intern("name"));
            rb_raise(rb_eRuntimeError, "no helpfile of `%s'",
                     StringValuePtr(name));
        }
        helpcontext = rb_funcall(target, rb_intern("helpcontext"), 0);
    } else {
        helpfile = target;
    }
    if (TYPE(helpfile) != T_STRING) {
        rb_raise(rb_eTypeError, "1st parameter must be (String|WIN32OLE_TYPE|WIN32OLE_METHOD)");
    }
    hwnd = ole_show_help(helpfile, helpcontext);
    if(hwnd == 0) {
        rb_raise(rb_eRuntimeError, "failed to open help file `%s'",
                 StringValuePtr(helpfile));
    }
    return Qnil;
}