pidfile.c 893 B

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  1. /* vi: set sw=4 ts=4: */
  2. /*
  3. * pid file routines
  4. *
  5. * Copyright (C) 2007 by Stephane Billiart <stephane.billiart@gmail.com>
  6. *
  7. * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  8. */
  9. /* Override ENABLE_FEATURE_PIDFILE */
  10. #define WANT_PIDFILE 1
  11. #include "libbb.h"
  12. smallint wrote_pidfile;
  13. void FAST_FUNC write_pidfile(const char *path)
  14. {
  15. int pid_fd;
  16. char *end;
  17. char buf[sizeof(int)*3 + 2];
  18. struct stat sb;
  19. if (!path)
  20. return;
  21. /* we will overwrite stale pidfile */
  22. pid_fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, 0666);
  23. if (pid_fd < 0)
  24. return;
  25. /* path can be "/dev/null"! Test for such cases */
  26. wrote_pidfile = (fstat(pid_fd, &sb) == 0) && S_ISREG(sb.st_mode);
  27. if (wrote_pidfile) {
  28. /* few bytes larger, but doesn't use stdio */
  29. end = utoa_to_buf(getpid(), buf, sizeof(buf));
  30. *end = '\n';
  31. full_write(pid_fd, buf, end - buf + 1);
  32. }
  33. close(pid_fd);
  34. }