1 /* $OpenBSD: strlcpy.c,v 1.7 2014/06/10 04:16:57 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 #include <lib/libkern/libkern.h> 20 21 /* 22 * Copy src to string dst of size siz. At most siz-1 characters 23 * will be copied. Always NUL terminates (unless siz == 0). 24 * Returns strlen(src); if retval >= siz, truncation occurred. 25 */ 26 size_t 27 strlcpy(char *dst, const char *src, size_t siz) 28 { 29 char *d = dst; 30 const char *s = src; 31 size_t n = siz; 32 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 41 /* Not enough room in dst, add NUL and traverse rest of src */ 42 if (n == 0) { 43 if (siz != 0) 44 *d = '\0'; /* NUL-terminate dst */ 45 while (*s++) 46 ; 47 } 48 49 return(s - src - 1); /* count does not include NUL */ 50 } 51