main(argc,args) char **args ; { register char *tape ; int i , j ; if (argc > 2) { usage : printf("usage : rew [[m]digit]\n") ; exit(1) ; } tape = "/dev/tap0" ; if (argc > 1) { j = 0 ; if (args[1][j] == 'm') { tape = "/dev/mt0" ; i = 7 ; j++ ; } else i = 8 ; if (args[1][j] != '\0') tape[i] = args[1][j] ; } i = open(tape,0) ; read(i,&j,sizeof(j)) ; close(i) ; }