external/bsd/am-utils/dist/libamu/strlcat.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (c) 1997-2009 Erez Zadok
   5  * Copyright (c) 1990 Jan-Simon Pendry
   6  * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
   7  * Copyright (c) 1990 The Regents of the University of California.
   8  * All rights reserved.
   9  *
  10  * This code is derived from software contributed to Berkeley by
  11  * Jan-Simon Pendry at Imperial College, London.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 3. All advertising materials mentioning features or use of this software
  22  *    must display the following acknowledgment:
  23  *      This product includes software developed by the University of
  24  *      California, Berkeley and its contributors.
  25  * 4. Neither the name of the University nor the names of its contributors
  26  *    may be used to endorse or promote products derived from this software
  27  *    without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  39  * SUCH DAMAGE.
  40  *
  41  *
  42  * File: am-utils/libamu/strlcat.c
  43  *
  44  */
  45
  46 #ifdef HAVE_CONFIG_H
  47 # include <config.h>
  48 #endif /* HAVE_CONFIG_H */
  49 #include <am_defs.h>
  50 #include <amu.h>
  51
  52 /*
  53  * Implementation of strlcat(3) from OpenBSD/NetBSD.
  54  */
  55
  56 /*
  57  * Appends src to string dst of size siz (unlike strncat, siz is the
  58  * full size of dst, not space left).  At most siz-1 characters
  59  * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
  60  * Returns strlen(src) + MIN(siz, strlen(initial dst)).
  61  * If retval >= siz, truncation occurred.
  62  */
  63 size_t
  64 strlcat(char *dst, const char *src, size_t siz)
  65 {
  66   char *d = dst;
  67   const char *s = src;
  68   size_t n = siz;
  69   size_t dlen;
  70
  71   /* Find the end of dst and adjust bytes left but don't go past end */
  72   while (n-- != 0 && *d != '\0')
  73     d++;
  74   dlen = d - dst;
  75   n = siz - dlen;
  76
  77   if (n == 0)
  78     return(dlen + strlen(s));
  79   while (*s != '\0') {
  80     if (n != 1) {
  81       *d++ = *s;
  82       n--;
  83     }
  84     s++;
  85   }
  86   *d = '\0';
  87
  88   return(dlen + (s - src));     /* count does not include NUL */
  89 }