Home | History | Annotate | Download | only in string
      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 (at) 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/types.h>
     20 #include <string.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 
     34 	/* Copy as many bytes as will fit */
     35 	if (n != 0) {
     36 		while (--n != 0) {
     37 			if ((*d++ = *s++) == '\0')
     38 				break;
     39 		}
     40 	}
     41 
     42 	/* Not enough room in dst, add NUL and traverse rest of src */
     43 	if (n == 0) {
     44 		if (siz != 0)
     45 			*d = '\0';		/* NUL-terminate dst */
     46 		while (*s++)
     47 			;
     48 	}
     49 
     50 	return(s - src - 1);	/* count does not include NUL */
     51 }
     52