getgrgid.c 1.8 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869
  1. /*
  2. * getgrgid.c - This file is part of the libc-8086/grp package for ELKS,
  3. * Copyright (C) 1995, 1996 Nat Friedman <ndf@linux.mit.edu>.
  4. *
  5. * This library is free software; you can redistribute it and/or
  6. * modify it under the terms of the GNU Library General Public
  7. * License as published by the Free Software Foundation; either
  8. * version 2 of the License, or (at your option) any later version.
  9. *
  10. * This library is distributed in the hope that it will be useful,
  11. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13. * Library General Public License for more details.
  14. *
  15. * You should have received a copy of the GNU Library General Public
  16. * License along with this library; if not, write to the Free
  17. * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18. *
  19. */
  20. #include <sys/types.h>
  21. #include <unistd.h>
  22. #include <fcntl.h>
  23. #include <paths.h>
  24. #include "config.h"
  25. #ifdef __UCLIBC_HAS_THREADS__
  26. #include <pthread.h>
  27. extern pthread_mutex_t __getgrent_lock;
  28. # define LOCK pthread_mutex_lock(&__getgrent_lock)
  29. # define UNLOCK pthread_mutex_unlock(&__getgrent_lock);
  30. #else
  31. # define LOCK
  32. # define UNLOCK
  33. #endif
  34. static char *line_buff = NULL;
  35. static char **members = NULL;
  36. struct group *getgrgid(const gid_t gid)
  37. {
  38. struct group *group;
  39. int grp_fd;
  40. if ((grp_fd = open(_PATH_GROUP, O_RDONLY)) < 0)
  41. return NULL;
  42. LOCK;
  43. while ((group = __getgrent(grp_fd, line_buff, members)) != NULL)
  44. if (group->gr_gid == gid) {
  45. close(grp_fd);
  46. UNLOCK;
  47. return group;
  48. }
  49. close(grp_fd);
  50. UNLOCK;
  51. return NULL;
  52. }
  53. #if 0
  54. /* Search for an entry with a matching group ID. */
  55. int getgrgid_r (gid_t gid, struct group *resultbuf, char *buffer,
  56. size_t buflen, struct group **result)
  57. {
  58. }
  59. #endif