strlcpy.c (2326B)
1 /* $Id: //depot/blt/lib/libc/strlcpy.c#1 $ */ 2 /* $OpenBSD: strlcpy.c,v 1.4 1999/05/01 18:56:41 millert Exp $ */ 3 4 /* 5 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. The name of the author may not be used to endorse or promote products 17 * derived from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, 20 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY 21 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 22 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 23 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 24 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 25 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 26 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 27 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 28 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include <string.h> 32 33 /* 34 * Copy src to string dst of size siz. At most siz-1 characters 35 * will be copied. Always NUL terminates (unless siz == 0). 36 * Returns strlen(src); if retval >= siz, truncation occurred. 37 */ 38 size_t strlcpy(dst, src, siz) 39 char *dst; 40 const char *src; 41 size_t siz; 42 { 43 register char *d = dst; 44 register const char *s = src; 45 register size_t n = siz; 46 47 /* Copy as many bytes as will fit */ 48 if (n != 0 && --n != 0) { 49 do { 50 if ((*d++ = *s++) == 0) 51 break; 52 } while (--n != 0); 53 } 54 55 /* Not enough room in dst, add NUL and traverse rest of src */ 56 if (n == 0) { 57 if (siz != 0) 58 *d = '\0'; /* NUL-terminate dst */ 59 while (*s++) 60 ; 61 } 62 63 return(s - src - 1); /* count does not include NUL */ 64 } 65