Line data    Source code

       1             : /*      $OpenBSD: strncpy.c,v 1.9 2014/06/10 04:16:57 deraadt Exp $     */
       2             : 
       3             : /*-
       4             :  * Copyright (c) 1990 The Regents of the University of California.
       5             :  * All rights reserved.
       6             :  *
       7             :  * This code is derived from software contributed to Berkeley by
       8             :  * Chris Torek.
       9             :  *
      10             :  * Redistribution and use in source and binary forms, with or without
      11             :  * modification, are permitted provided that the following conditions
      12             :  * are met:
      13             :  * 1. Redistributions of source code must retain the above copyright
      14             :  *    notice, this list of conditions and the following disclaimer.
      15             :  * 2. Redistributions in binary form must reproduce the above copyright
      16             :  *    notice, this list of conditions and the following disclaimer in the
      17             :  *    documentation and/or other materials provided with the distribution.
      18             :  * 3. Neither the name of the University nor the names of its contributors
      19             :  *    may be used to endorse or promote products derived from this software
      20             :  *    without specific prior written permission.
      21             :  *
      22             :  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
      23             :  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
      24             :  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
      25             :  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
      26             :  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
      27             :  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
      28             :  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
      29             :  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
      30             :  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
      31             :  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
      32             :  * SUCH DAMAGE.
      33             :  */
      34             : 
      35             : #include <lib/libkern/libkern.h>
      36             : 
      37             : /*
      38             :  * Copy src to dst, truncating or null-padding to always copy n bytes.
      39             :  * Return dst.
      40             :  */
      41             : char *
      42           0 : strncpy(char *dst, const char *src, size_t n)
      43             : {
      44           0 :         if (n != 0) {
      45             :                 char *d = dst;
      46             :                 const char *s = src;
      47             : 
      48           0 :                 do {
      49           0 :                         if ((*d++ = *s++) == 0) {
      50             :                                 /* NUL pad the remaining n-1 bytes */
      51           0 :                                 while (--n != 0)
      52           0 :                                         *d++ = 0;
      53             :                                 break;
      54             :                         }
      55           0 :                 } while (--n != 0);
      56           0 :         }
      57           0 :         return (dst);
      58             : }