logname.c 1.2 KB

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  1. /* vi: set sw=4 ts=4: */
  2. /*
  3. * Mini logname implementation for busybox
  4. *
  5. * Copyright (C) 2000 Edward Betts <edward@debian.org>.
  6. *
  7. * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  8. */
  9. /* BB_AUDIT SUSv3 compliant */
  10. /* http://www.opengroup.org/onlinepubs/007904975/utilities/logname.html */
  11. /* Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org)
  12. *
  13. * SUSv3 specifies the string used is that returned from getlogin().
  14. * The previous implementation used getpwuid() for geteuid(), which
  15. * is _not_ the same. Erik apparently made this change almost 3 years
  16. * ago to avoid failing when no utmp was available. However, the
  17. * correct course of action wrt SUSv3 for a failing getlogin() is
  18. * a diagnostic message and an error return.
  19. */
  20. #include "libbb.h"
  21. /* This is a NOFORK applet. Be very careful! */
  22. int logname_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  23. int logname_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
  24. {
  25. char buf[64];
  26. if (argv[1]) {
  27. bb_show_usage();
  28. }
  29. /* Using _r function - avoid pulling in static buffer from libc */
  30. if (getlogin_r(buf, sizeof(buf)) == 0) {
  31. puts(buf);
  32. return fflush_all();
  33. }
  34. bb_perror_msg_and_die("getlogin");
  35. }