1 /* $OpenBSD: strlcpy.c,v 1.11 2006/05/05 15:27:38 millert 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/cdefs.h> 20 __FBSDID("$FreeBSD$"); 21 22 #include <sys/types.h> 23 #include <sys/libkern.h> 24 25 /* 26 * Copy src to string dst of size siz. At most siz-1 characters 27 * will be copied. Always NUL terminates (unless siz == 0). 28 * Returns strlen(src); if retval >= siz, truncation occurred. 29 */ 30 size_t 31 strlcpy(char * __restrict dst, const char * __restrict src, size_t siz) 32 { 33 char *d = dst; 34 const char *s = src; 35 size_t n = siz; 36 37 /* Copy as many bytes as will fit */ 38 if (n != 0) { 39 while (--n != 0) { 40 if ((*d++ = *s++) == '\0') 41 break; 42 } 43 } 44 45 /* Not enough room in dst, add NUL and traverse rest of src */ 46 if (n == 0) { 47 if (siz != 0) 48 *d = '\0'; /* NUL-terminate dst */ 49 while (*s++) 50 ; 51 } 52 53 return(s - src - 1); /* count does not include NUL */ 54 } 55