strlcpy.c 2.5 KB

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  1. /* $OpenBSD: strlcpy.c,v 1.4 1999/05/01 18:56:41 millert Exp $ */
  2. /*
  3. * Copyright (c) 1998 Todd C. Miller <[email protected]>
  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. * 3. The name of the author may not be used to endorse or promote products
  15. * derived from this software without specific prior written permission.
  16. *
  17. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  18. * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  19. * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
  20. * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  21. * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  22. * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  23. * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  24. * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  25. * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  26. * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27. */
  28. #if defined(LIBC_SCCS) && !defined(lint)
  29. static char *rcsid = "$OpenBSD: strlcpy.c,v 1.4 1999/05/01 18:56:41 millert Exp $";
  30. #endif /* LIBC_SCCS and not lint */
  31. #include <sys/types.h>
  32. #include <string.h>
  33. size_t strlcpy(char *dst, const char *src, size_t siz);
  34. /*
  35. * Copy src to string dst of size siz. At most siz-1 characters
  36. * will be copied. Always NUL terminates (unless siz == 0).
  37. * Returns strlen(src); if retval >= siz, truncation occurred.
  38. */
  39. size_t strlcpy(char *dst, const char *src, size_t siz)
  40. {
  41. register char *d = dst;
  42. register const char *s = src;
  43. register size_t n = siz;
  44. /* Copy as many bytes as will fit */
  45. if (n != 0 && --n != 0) {
  46. do {
  47. if ((*d++ = *s++) == 0)
  48. break;
  49. } while (--n != 0);
  50. }
  51. /* Not enough room in dst, add NUL and traverse rest of src */
  52. if (n == 0) {
  53. if (siz != 0)
  54. *d = '\0'; /* NUL-terminate dst */
  55. while (*s++)
  56. ;
  57. }
  58. return(s - src - 1); /* count does not include NUL */
  59. }