#include #include #include #include #include int main(int argc, char *argv[]) { int i; if (argc < 2) exit(1); for (i = 1; i < argc; ++i) { char *endptr; int fd; fd = strtol(argv[i], &endptr, 10); if (*endptr != '\0') exit(1); if (close(fd) < 0) { int error = errno; if (error != EBADF) { warnx("close error %d", error); exit(2); } } else { warnx("%d is still valid", fd); exit(2); } } exit(0); }