/usr.bin/tty/tty.c

https://bitbucket.org/freebsd/freebsd-head/ · C · 79 lines · 42 code · 9 blank · 28 comment · 4 complexity · a8aa7935883de00cdbdef72937c8e0d5 MD5 · raw file

  1. /*
  2. * Copyright (c) 1988, 1993
  3. * The Regents of the University of California. All rights reserved.
  4. *
  5. * Redistribution and use in source and binary forms, with or without
  6. * modification, are permitted provided that the following conditions
  7. * are met:
  8. * 1. Redistributions of source code must retain the above copyright
  9. * notice, this list of conditions and the following disclaimer.
  10. * 2. Redistributions in binary form must reproduce the above copyright
  11. * notice, this list of conditions and the following disclaimer in the
  12. * documentation and/or other materials provided with the distribution.
  13. * 4. Neither the name of the University nor the names of its contributors
  14. * may be used to endorse or promote products derived from this software
  15. * without specific prior written permission.
  16. *
  17. * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20. * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27. * SUCH DAMAGE.
  28. */
  29. #ifndef lint
  30. static const char copyright[] =
  31. "@(#) Copyright (c) 1988, 1993\n\
  32. The Regents of the University of California. All rights reserved.\n";
  33. #endif /* not lint */
  34. #ifndef lint
  35. #if 0
  36. static char sccsid[] = "@(#)tty.c 8.1 (Berkeley) 6/6/93";
  37. #endif
  38. #endif /* not lint */
  39. #include <sys/cdefs.h>
  40. __FBSDID("$FreeBSD$");
  41. #include <stdio.h>
  42. #include <stdlib.h>
  43. #include <unistd.h>
  44. static void usage(void);
  45. int
  46. main(int argc, char *argv[])
  47. {
  48. int ch, sflag;
  49. char *t;
  50. sflag = 0;
  51. while ((ch = getopt(argc, argv, "s")) != -1)
  52. switch (ch) {
  53. case 's':
  54. sflag = 1;
  55. break;
  56. case '?':
  57. default:
  58. usage();
  59. }
  60. t = ttyname(0);
  61. if (!sflag)
  62. puts(t ? t : "not a tty");
  63. exit(t ? 0 : 1);
  64. }
  65. static void
  66. usage(void)
  67. {
  68. fprintf(stderr, "usage: tty [-s]\n");
  69. exit(2);
  70. }