In article <199811181009.LAA14841@natt.e.kth.se> lha@stacken.kth.se writes:
>-                       modnum = atoi(optarg);
>+                       modnum = strtol(optarg, &endptr, 0);
>+                       if (*endptr != '\0')
>+                               errx(1, "not a valid number");
>                        break;  /* number */
>                case 'n':
>                        modname = optarg;

It is not enough to check strtol's endptr. You need to check the result
for LONG_MIN and LONG_MAX and ERANGE.

christos