btowc.c 1.9 KB

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  1. /* $OpenBSD: btowc.c,v 1.2 2012/12/05 23:20:00 deraadt Exp $ */
  2. /*-
  3. * Copyright (c) 2002, 2003 Tim J. Robbins.
  4. * All rights reserved.
  5. *
  6. * Redistribution and use in source and binary forms, with or without
  7. * modification, are permitted provided that the following conditions
  8. * are met:
  9. * 1. Redistributions of source code must retain the above copyright
  10. * notice, this list of conditions and the following disclaimer.
  11. * 2. Redistributions in binary form must reproduce the above copyright
  12. * notice, this list of conditions and the following disclaimer in the
  13. * documentation and/or other materials provided with the distribution.
  14. *
  15. * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18. * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25. * SUCH DAMAGE.
  26. */
  27. #include <sys/limits.h>
  28. #include <stdio.h>
  29. #include <string.h>
  30. #include <wchar.h>
  31. wint_t btowc(int c)
  32. {
  33. mbstate_t mbs;
  34. char cc;
  35. wchar_t wc;
  36. /* align with actual outputs of glibc btowc */
  37. if (c < 0 || c > SCHAR_MAX || c == EOF)
  38. return (WEOF);
  39. /*
  40. * We expect mbrtowc() to return 0 or 1, hence the check for n > 1
  41. * which detects error return values as well as "impossible" byte
  42. * counts.
  43. */
  44. memset(&mbs, 0, sizeof(mbs));
  45. cc = (char)c;
  46. if (mbrtowc(&wc, &cc, 1, &mbs) > 1)
  47. return (WEOF);
  48. return (wc);
  49. }