daemon.c 2.8 KB

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  1. /* vi: set sw=4 ts=4: */
  2. /* daemon implementation for uClibc
  3. *
  4. * Copyright (c) 1990, 1993
  5. * The Regents of the University of California. All rights reserved.
  6. *
  7. * Redistribution and use in source and binary forms, with or without
  8. * modification, are permitted provided that the following conditions
  9. * are met:
  10. * 1. Redistributions of source code must retain the above copyright
  11. * notice, this list of conditions and the following disclaimer.
  12. * 2. Redistributions in binary form must reproduce the above copyright
  13. * notice, this list of conditions and the following disclaimer in the
  14. * documentation and/or other materials provided with the distribution.
  15. *
  16. * 3. <BSD Advertising Clause omitted per the July 22, 1999 licensing change
  17. * ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change>
  18. *
  19. * 4. Neither the name of the University nor the names of its contributors
  20. * may be used to endorse or promote products derived from this software
  21. * without specific prior written permission.
  22. *
  23. * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26. * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33. * SUCH DAMAGE.
  34. */
  35. /*
  36. * Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
  37. *
  38. * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
  39. * Modified for uClibc by Erik Andersen <andersen@uclibc.org>
  40. */
  41. #include <stdio.h>
  42. #include <features.h>
  43. #include <fcntl.h>
  44. #include <paths.h>
  45. #include <unistd.h>
  46. #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_UNIX98)
  47. libc_hidden_proto(open)
  48. libc_hidden_proto(close)
  49. libc_hidden_proto(_exit)
  50. libc_hidden_proto(dup2)
  51. libc_hidden_proto(setsid)
  52. libc_hidden_proto(chdir)
  53. libc_hidden_proto(fork)
  54. int daemon( int nochdir, int noclose )
  55. {
  56. int fd;
  57. switch (fork()) {
  58. case -1:
  59. return(-1);
  60. case 0:
  61. break;
  62. default:
  63. _exit(0);
  64. }
  65. if (setsid() == -1)
  66. return(-1);
  67. /* Make certain we are not a session leader, or else we
  68. * might reacquire a controlling terminal */
  69. if (fork())
  70. _exit(0);
  71. if (!nochdir)
  72. chdir("/");
  73. if (!noclose && (fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
  74. dup2(fd, STDIN_FILENO);
  75. dup2(fd, STDOUT_FILENO);
  76. dup2(fd, STDERR_FILENO);
  77. if (fd > 2)
  78. close(fd);
  79. }
  80. return(0);
  81. }
  82. #endif