ubase

suckless linux base utils
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strlcat.c (1814B)


      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 <string.h>
     18 #include <sys/types.h>
     19 
     20 #include "../util.h"
     21 
     22 /*
     23  * Appends src to string dst of size siz (unlike strncat, siz is the
     24  * full size of dst, not space left). At most siz-1 characters
     25  * will be copied. Always NUL terminates (unless siz <= strlen(dst)).
     26  * Returns strlen(src) + MIN(siz, strlen(initial dst)).
     27  * If retval >= siz, truncation occurred.
     28  */
     29 size_t
     30 strlcat(char *dst, const char *src, size_t siz)
     31 {
     32 	char *d = dst;
     33 	const char *s = src;
     34 	size_t n = siz;
     35 	size_t dlen;
     36 	/* Find the end of dst and adjust bytes left but don't go past end */
     37 	while (n-- != 0 && *d != '\0')
     38 		d++;
     39 	dlen = d - dst;
     40 	n = siz - dlen;
     41 	if (n == 0)
     42 		return(dlen + strlen(s));
     43 	while (*s != '\0') {
     44 		if (n != 1) {
     45 			*d++ = *s;
     46 			n--;
     47 		}
     48 		s++;
     49 	}
     50 	*d = '\0';
     51 	return(dlen + (s - src)); /* count does not include NUL */
     52 }
     53 
     54 size_t
     55 estrlcat(char *dst, const char *src, size_t siz)
     56 {
     57 	size_t ret;
     58 
     59 	if ((ret = strlcat(dst, src, siz)) >= siz)
     60 		eprintf("strlcat: input string too long\n");
     61 
     62 	return ret;
     63 }