usr/src/lib/libast/common/string/strlcat.c

   1 /***********************************************************************
   2 *                                                                      *
   3 *               This software is part of the ast package               *
   4 *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
   5 *                      and is licensed under the                       *
   6 *                  Common Public License, Version 1.0                  *
   7 *                    by AT&T Intellectual Property                     *
   8 *                                                                      *
   9 *                A copy of the License is available at                 *
  10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
  11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
  12 *                                                                      *
  13 *              Information and Software Systems Research               *
  14 *                            AT&T Research                             *
  15 *                           Florham Park NJ                            *
  16 *                                                                      *
  17 *                 Glenn Fowler <gsf@research.att.com>                  *
  18 *                  David Korn <dgk@research.att.com>                   *
  19 *                   Phong Vo <kpv@research.att.com>                    *
  20 *                                                                      *
  21 ***********************************************************************/
  22 #pragma prototyped
  23 /*
  24  * strlcat implementation
  25  */
  26
  27 #define strlcat         ______strlcat
  28
  29 #include <ast.h>
  30
  31 #undef  strlcat
  32
  33 #undef  _def_map_ast
  34 #include <ast_map.h>
  35
  36 #if _lib_strlcat
  37
  38 NoN(strlcat)
  39
  40 #else
  41
  42 /*
  43  * append t onto s limiting total size of s to n
  44  * s 0 terminated if n>0
  45  * min(n,strlen(s))+strlen(t) returned
  46  */
  47
  48 #if defined(__EXPORT__)
  49 #define extern  __EXPORT__
  50 #endif
  51
  52 extern size_t
  53 strlcat(register char* s, register const char* t, register size_t n)
  54 {
  55         register size_t m;
  56         const char*     o = t;
  57
  58         if (m = n)
  59         {
  60                 while (n && *s)
  61                 {
  62                         n--;
  63                         s++;
  64                 }
  65                 m -= n;
  66                 if (n)
  67                         do
  68                         {
  69                                 if (!--n)
  70                                 {
  71                                         *s = 0;
  72                                         break;
  73                                 }
  74                         } while (*s++ = *t++);
  75                 else
  76                         *s = 0;
  77         }
  78         if (!n)
  79                 while (*t++);
  80         return (t - o) + m - 1;
  81 }
  82
  83 #endif