if ( (argc == 1) || (cflag & dflag) || !(cflag | dflag) || ((argc - optind) < 2) ) {
fprintf(stderr, "Usage: %s [-cdt] sourcefile targetfile\n", argv[0]);
if ( (argc == 1) || (cflag & dflag) || !(cflag | dflag) || ((argc - optind) < 2) ) {
fprintf(stderr, "Usage: %s [-cdt] sourcefile targetfile\n", argv[0]);