- if (strncmp(dev, "/dev/", 5) == 0 &&
- strrchr(dev, '/') == dev + 4 &&
- dev[5] != 0)
- { /* Create lock file (to be inter-operable with other programs) */
- /* This is racy, but what we can do - see also comments in uucp / cu */
- int tmp = CHECK(mkstemp(template));
- on_exit(rm_file, template);
- char pid[20];
- snprintf(pid, sizeof(pid), "%u", getpid());
- CHECK(write(tmp, pid, strlen(pid)));
- close(tmp);
- snprintf(lockfile, sizeof(lockfile), "/var/lock/LCK..%s", dev + 5);
- retry:
- if (link(template, lockfile) == -1) {
- tmp = CHECK(open(lockfile, O_RDONLY));
- CHECK(read(tmp, pid, sizeof(pid)));
- close(tmp);
- int p = atoi(pid);
- char proc[50];
- snprintf(proc, sizeof(proc), "/proc/%d", p);
- if (access(proc, F_OK) == 0) {
- fprintf(stderr, "%s is used by PID %d\n", dev, p);
- exit(1);
- }
- fprintf(stderr, "Stale lock file %s (PID %d) - removing it!\n", lockfile, p);
- CHECK(unlink(lockfile));
- goto retry;
- }
- rm_file(0, template);
- on_exit(rm_file, lockfile);