sigset.c 2.3 KB

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  1. /* Copyright (C) 1998, 2000, 2005 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. The GNU C Library is free software; you can redistribute it and/or
  4. modify it under the terms of the GNU Lesser General Public
  5. License as published by the Free Software Foundation; either
  6. version 2.1 of the License, or (at your option) any later version.
  7. The GNU C Library is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10. Lesser General Public License for more details.
  11. You should have received a copy of the GNU Lesser General Public
  12. License along with the GNU C Library; if not, write to the Free
  13. Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  14. 02111-1307 USA. */
  15. #include <errno.h>
  16. #define __need_NULL
  17. #include <stddef.h>
  18. #include <signal.h>
  19. #include <string.h> /* For the real memset prototype. */
  20. libc_hidden_proto(sigaction)
  21. libc_hidden_proto(sigprocmask)
  22. /* Set the disposition for SIG. */
  23. __sighandler_t
  24. sigset (sig, disp)
  25. int sig;
  26. __sighandler_t disp;
  27. {
  28. struct sigaction act, oact;
  29. sigset_t set;
  30. #ifdef SIG_HOLD
  31. /* Handle SIG_HOLD first. */
  32. if (disp == SIG_HOLD)
  33. {
  34. /* Create an empty signal set. */
  35. if (__sigemptyset (&set) < 0)
  36. return SIG_ERR;
  37. /* Add the specified signal. */
  38. if (__sigaddset (&set, sig) < 0)
  39. return SIG_ERR;
  40. /* Add the signal set to the current signal mask. */
  41. if (sigprocmask (SIG_BLOCK, &set, NULL) < 0)
  42. return SIG_ERR;
  43. return SIG_HOLD;
  44. }
  45. #endif /* SIG_HOLD */
  46. /* Check signal extents to protect __sigismember. */
  47. if (disp == SIG_ERR || sig < 1 || sig >= NSIG)
  48. {
  49. __set_errno (EINVAL);
  50. return SIG_ERR;
  51. }
  52. act.sa_handler = disp;
  53. if (__sigemptyset (&act.sa_mask) < 0)
  54. return SIG_ERR;
  55. act.sa_flags = 0;
  56. if (sigaction (sig, &act, &oact) < 0)
  57. return SIG_ERR;
  58. /* Create an empty signal set. */
  59. if (__sigemptyset (&set) < 0)
  60. return SIG_ERR;
  61. /* Add the specified signal. */
  62. if (__sigaddset (&set, sig) < 0)
  63. return SIG_ERR;
  64. /* Remove the signal set from the current signal mask. */
  65. if (sigprocmask (SIG_UNBLOCK, &set, NULL) < 0)
  66. return SIG_ERR;
  67. return oact.sa_handler;
  68. }