strsep.c 1.7 KB

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  1. /* Copyright (C) 1992, 93, 96, 97, 98, 99, 2004 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, see
  13. <http://www.gnu.org/licenses/>. */
  14. #include <string.h>
  15. #ifdef __USE_BSD
  16. char *strsep (char **stringp, const char *delim)
  17. {
  18. char *begin, *end;
  19. begin = *stringp;
  20. if (begin == NULL)
  21. return NULL;
  22. /* A frequent case is when the delimiter string contains only one
  23. character. Here we don't need to call the expensive `strpbrk'
  24. function and instead work using `strchr'. */
  25. if (delim[0] == '\0' || delim[1] == '\0')
  26. {
  27. char ch = delim[0];
  28. if (ch == '\0')
  29. end = NULL;
  30. else
  31. {
  32. if (*begin == ch)
  33. end = begin;
  34. else if (*begin == '\0')
  35. end = NULL;
  36. else
  37. end = strchr (begin + 1, ch);
  38. }
  39. }
  40. else
  41. /* Find the end of the token. */
  42. end = strpbrk (begin, delim);
  43. if (end)
  44. {
  45. /* Terminate the token and set *STRINGP past NUL character. */
  46. *end++ = '\0';
  47. *stringp = end;
  48. }
  49. else
  50. /* No more delimiters; this is the last token. */
  51. *stringp = NULL;
  52. return begin;
  53. }
  54. libc_hidden_def(strsep)
  55. #endif