strlcpy.c (1526B)
1 /* 2 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com> 3 * 4 * Permission to use, copy, modify, and distribute this software for any 5 * purpose with or without fee is hereby granted, provided that the above 6 * copyright notice and this permission notice appear in all copies. 7 * 8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 15 */ 16 17 #include <stdio.h> 18 #include <stdlib.h> 19 #include <string.h> 20 #include <sys/types.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 /* Copy as many bytes as will fit */ 34 if (n != 0) { 35 while (--n != 0) { 36 if ((*d++ = *s++) == '\0') 37 break; 38 } 39 } 40 /* Not enough room in dst, add NUL and traverse rest of src */ 41 if (n == 0) { 42 if (siz != 0) 43 *d = '\0'; /* NUL-terminate dst */ 44 while (*s++) 45 ; 46 } 47 return(s - src - 1); /* count does not include NUL */ 48 }