1 /* $OpenBSD: strlcpy.c,v 1.6 2009/10/27 23:59:35 deraadt 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 #if !defined(_KERNEL) && !defined(_STANDALONE) 20 #include <sys/types.h> 21 #include <string.h> 22 #else 23 #include <lib/libkern/libkern.h> 24 #endif 25 26 /* 27 * Copy src to string dst of size siz. At most siz-1 characters 28 * will be copied. Always NUL terminates (unless siz == 0). 29 * Returns strlen(src); if retval >= siz, truncation occurred. 30 */ 31 size_t 32 strlcpy(char *dst, const char *src, size_t siz) 33 { 34 char *d = dst; 35 const char *s = src; 36 size_t n = siz; 37 38 /* Copy as many bytes as will fit */ 39 if (n != 0 && --n != 0) { 40 do { 41 if ((*d++ = *s++) == 0) 42 break; 43 } while (--n != 0); 44 } 45 46 /* Not enough room in dst, add NUL and traverse rest of src */ 47 if (n == 0) { 48 if (siz != 0) 49 *d = '\0'; /* NUL-terminate dst */ 50 while (*s++) 51 ; 52 } 53 54 return(s - src - 1); /* count does not include NUL */ 55 } 56