external/bsd/am-utils/dist/libamu/strstr.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 the Free Software Foundation, Inc. GNU utilities.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. All advertising materials mentioning features or use of this software
  21  *    must display the following acknowledgment:
  22  *      This product includes software developed by the University of
  23  *      California, Berkeley and its contributors.
  24  * 4. Neither the name of the University nor the names of its contributors
  25  *    may be used to endorse or promote products derived from this software
  26  *    without specific prior written permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  38  * SUCH DAMAGE.
  39  *
  40  *
  41  * File: am-utils/libamu/strstr.c
  42  *
  43  */
  44
  45 #ifdef HAVE_CONFIG_H
  46 # include <config.h>
  47 #endif /* HAVE_CONFIG_H */
  48 #include <am_defs.h>
  49 #include <amu.h>
  50
  51
  52 /* strstr.c -- return the offset of one string within another
  53    Copyright (C) 1989, 1990 Free Software Foundation, Inc.
  54
  55    This program is free software; you can redistribute it and/or modify
  56    it under the terms of the GNU General Public License as published by
  57    the Free Software Foundation; either version 2, or (at your option)
  58    any later version.
  59
  60    This program is distributed in the hope that it will be useful,
  61    but WITHOUT ANY WARRANTY; without even the implied warranty of
  62    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  63    GNU General Public License for more details.
  64
  65    You should have received a copy of the GNU General Public License
  66    along with this program; if not, write to the Free Software
  67    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  68
  69 /* Author:
  70         Mike Rendell                    Department of Computer Science
  71         michael@garfield.mun.edu        Memorial University of Newfoundland
  72         ..!uunet!garfield!michael       St. John's, Nfld., Canada
  73         (709) 737-4550                  A1C 5S7
  74 */
  75
  76
  77 /*
  78  * Return the starting address of string S2 in S1;
  79  * return 0 if it is not found.
  80  */
  81 char *
  82 strstr(char *s1, char *s2)
  83 {
  84   int i;
  85   char *p1;
  86   char *p2;
  87   char *s = s1;
  88
  89   for (p2 = s2, i = 0; *s; p2 = s2, i++, s++) {
  90     for (p1 = s; *p1 && *p2 && *p1 == *p2; p1++, p2++)
  91       ;
  92     if (!*p2)
  93       break;
  94   }
  95   if (!*p2)
  96     return s1 + i;
  97
  98   return 0;
  99 }