usr/src/lib/libast/common/string/strncopy.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 #include <ast.h>
  25
  26 /*
  27  * copy up to n bytes of string f into t
  28  * trailing 0 always added to t, even if n==0
  29  * pointer to the copied 0 returned
  30  */
  31
  32 char*
  33 strncopy(register char* t, register const char* f, size_t n)
  34 {
  35         register char*  e = t + n - 1;
  36
  37         do
  38         {
  39                 if (t >= e)
  40                 {
  41                         *t = 0;
  42                         return t;
  43                 }
  44         } while (*t++ = *f++);
  45         return t - 1;
  46 }