#include #include #include #include char *progname; int main(int argc, char **argv) { unsigned long int length; length = 0; progname = argv[0]; if (argc != 2) { fprintf(stderr, "%s: must be given a duration\n", progname); return 1; } length = strtol(argv[1], NULL, 10); if (length == LONG_MAX) { fprintf(stderr, "%s: number is too large: %s\n", progname, argv[1]); return 1; } usleep(length); return 0; }