strcspn.c 2.2 KB

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  1. /* $OpenBSD: strcspn.c,v 1.6 2015/08/31 02:53:57 guenther Exp $ */
  2. /*-
  3. * Copyright (c) 1990 The Regents of the University of California.
  4. * All rights reserved.
  5. *
  6. * This code is derived from software contributed to Berkeley by
  7. * Chris Torek.
  8. *
  9. * Redistribution and use in source and binary forms, with or without
  10. * modification, are permitted provided that the following conditions
  11. * are met:
  12. * 1. Redistributions of source code must retain the above copyright
  13. * notice, this list of conditions and the following disclaimer.
  14. * 2. Redistributions in binary form must reproduce the above copyright
  15. * notice, this list of conditions and the following disclaimer in the
  16. * documentation and/or other materials provided with the distribution.
  17. * 3. Neither the name of the University nor the names of its contributors
  18. * may be used to endorse or promote products derived from this software
  19. * without specific prior written permission.
  20. *
  21. * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24. * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31. * SUCH DAMAGE.
  32. */
  33. #include <string.h>
  34. /*
  35. * Span the complement of string s2.
  36. */
  37. size_t
  38. __strcspn(const char *s1, const char *s2)
  39. {
  40. const char *p, *spanp;
  41. char c, sc;
  42. /*
  43. * Stop as soon as we find any character from s2. Note that there
  44. * must be a NUL in s2; it suffices to stop when we find that, too.
  45. */
  46. for (p = s1;;) {
  47. c = *p++;
  48. spanp = s2;
  49. do {
  50. if ((sc = *spanp++) == c)
  51. return (p - 1 - s1);
  52. } while (sc != 0);
  53. }
  54. /* NOTREACHED */
  55. }
  56. size_t
  57. strcspn(const char *s1, const char *s2)
  58. {
  59. return __strcspn(s1, s2);
  60. }