strlcpy.c 1.7 KB

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  1. /* $OpenBSD: strlcpy.c,v 1.8 2003/06/17 21:56:24 millert Exp $ */
  2. /*
  3. * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
  4. *
  5. * Permission to use, copy, modify, and distribute this software for any
  6. * purpose with or without fee is hereby granted, provided that the above
  7. * copyright notice and this permission notice appear in all copies.
  8. *
  9. * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10. * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11. * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12. * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13. * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14. * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15. * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16. */
  17. #if defined(LIBC_SCCS) && !defined(lint)
  18. static char *rcsid = "$OpenBSD: strlcpy.c,v 1.8 2003/06/17 21:56:24 millert Exp $";
  19. #endif /* LIBC_SCCS and not lint */
  20. #include <sys/types.h>
  21. #include <string.h>
  22. /*
  23. * Copy src to string dst of size siz. At most siz-1 characters
  24. * will be copied. Always NUL terminates (unless siz == 0).
  25. * Returns strlen(src); if retval >= siz, truncation occurred.
  26. */
  27. size_t
  28. strlcpy(char *dst, const char *src, size_t siz)
  29. {
  30. register char *d = dst;
  31. register const char *s = src;
  32. register size_t n = siz;
  33. /* Copy as many bytes as will fit */
  34. if (n != 0 && --n != 0) {
  35. do {
  36. if ((*d++ = *s++) == 0)
  37. break;
  38. } while (--n != 0);
  39. }
  40. /* Not enough room in dst, add NUL and traverse rest of src */
  41. if (n == 0) {
  42. if (siz != 0)
  43. *d = '\0'; /* NUL-terminate dst */
  44. while (*s++)
  45. ;
  46. }
  47. return(s - src - 1); /* count does not include NUL */
  48. }