Listing 4. Ttchmodd: ToolTalk Message Receiver

void ToolTalkCB (w, clientData, callData)
/*  widget id	   */
Widget	  w;
/*  data from application   */
xTpointer       clientData;
/*  data from widget class  */
XtPointer       callData;
{
Tt_message incoming;
Tt_status ttrc;
int ttmark, args;
char *filename;
char *mode;
char command[BUFSIZ];
XmString xmcmd;
ttmark = tt_mark();
incoming = tt_message_receive();
ToolTalkAbort("ToolTalkCB(): 
	tt_message_receive",
	tt_ptr_error(incoming));
if (incoming && (0 == 
	strcmp(tt_message_op(incoming), "Chmod")))
	{
	args = tt_message_args_count(incoming);
	ToolTalkAbort("ToolTalkCB():
		tt_message_args_count",
		tt_int_error(args));
	filename = tt_message_arg_val(incoming, 0);
	ToolTalkAbort("ToolTalkCB(): 
		tt_message_arg_val",
		tt_ptr_error(filename));
	mode = tt_message_arg_val(incoming, 1);
	ToolTalkAbort("ToolTalkCB(): 
		tt_message_arg_val",
		tt_ptr_error(mode));
	ttrc = tt_message_reply(incoming);
	ToolTalkAbort("ToolTalkCB(): 
		tt_message_destroy", ttrc);
	sprintf(command, 
		"/bin/chmod %s %s\n", 
		mode, filename);
	xmcmd = XmStringCreateLocalized(command);
	XmCommandSetValue(w, xmcmd);
	XmStringFree(xmcmd);
	} 
else {
	printf("ToolTalkCB(): unknown message %s.\n",
		tt_message_op(incoming));
	}
ttrc = tt_message_destroy(incoming);
ToolTalkAbort("ToolTalkCB(): 
	tt_message_destroy", ttrc);
tt_release(ttmark);
}
ToolTalkAbort(char *procname, Tt_status errid)
{
if (tt_is_err(errid)) {
	fprintf(stderr, 
		"%s returned ToolTalk error: %s\n",
		procname, tt_status_message(errid));
	exit(1);
	}
}