#include #include #include #include double convert(const char *num) { if (atof(num) <= 0) { fprintf(stderr, "sleep: %s < 1\n", num); exit(1); } return atof(num); } int main(const int argc, const char **argv) { if (argc == 1 || !strcmp(argv[argc - 1], "--help")) { printf("sleep [num[m - minute / h - hour / d - days]] / [inf (infinity)]\n"); return 0; } if (!strcmp(argv[1], "inf")) for (;;) sleep(1); double sec = 0; for (int i = 1; i < argc; i++) { switch (argv[i][strlen(argv[i]) - 1]) { case 'd': sec += convert(argv[i]) * 86400; break; case 'h': sec += convert(argv[i]) * 3600; break; case 'm': sec += convert(argv[i]) * 60; break; default: sec += convert(argv[i]); } } usleep(sec * 1000000); return 0; }