strlcpy.c (1559B)
1 /* $OpenBSD: strlcpy.c,v 1.10 2005/08/08 08:05:37 espie Exp $ */ 2 3 /* 4 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #include <sys/types.h> 20 #include <string.h> 21 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 char *d = dst; 31 const char *s = src; 32 size_t n = siz; 33 34 /* Copy as many bytes as will fit */ 35 if (n != 0) { 36 while (--n != 0) { 37 if ((*d++ = *s++) == '\0') 38 break; 39 } 40 } 41 42 /* Not enough room in dst, add NUL and traverse rest of src */ 43 if (n == 0) { 44 if (siz != 0) 45 *d = '\0'; /* NUL-terminate dst */ 46 while (*s++) 47 ; 48 } 49 50 return(s - src - 1); /* count does not include NUL */ 51 }