nsprpub/lib/libc/src/strstr.c

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
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  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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  14  *
  15  * The Original Code is the Netscape Portable Runtime (NSPR).
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  17  * The Initial Developer of the Original Code is
  18  * Netscape Communications Corporation.
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  20  * the Initial Developer. All Rights Reserved.
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  24  * Alternatively, the contents of this file may be used under the terms of
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  36  * ***** END LICENSE BLOCK ***** */
  37
  38 #include "plstr.h"
  39 #include <string.h>
  40
  41 PR_IMPLEMENT(char *)
  42 PL_strstr(const char *big, const char *little)
  43 {
  44     if( ((const char *)0 == big) || ((const char *)0 == little) ) return (char *)0;
  45     if( ((char)0 == *big) || ((char)0 == *little) ) return (char *)0;
  46
  47     return strstr(big, little);
  48 }
  49
  50 PR_IMPLEMENT(char *)
  51 PL_strrstr(const char *big, const char *little)
  52 {
  53     const char *p;
  54     size_t ll;
  55     size_t bl;
  56
  57     if( ((const char *)0 == big) || ((const char *)0 == little) ) return (char *)0;
  58     if( ((char)0 == *big) || ((char)0 == *little) ) return (char *)0;
  59
  60     ll = strlen(little);
  61     bl = strlen(big);
  62     if( bl < ll ) return (char *)0;
  63     p = &big[ bl - ll ];
  64
  65     for( ; p >= big; p-- )
  66         if( *little == *p )
  67             if( 0 == strncmp(p, little, ll) )
  68                 return (char *)p;
  69
  70     return (char *)0;
  71 }
  72
  73 PR_IMPLEMENT(char *)
  74 PL_strnstr(const char *big, const char *little, PRUint32 max)
  75 {
  76     size_t ll;
  77
  78     if( ((const char *)0 == big) || ((const char *)0 == little) ) return (char *)0;
  79     if( ((char)0 == *big) || ((char)0 == *little) ) return (char *)0;
  80
  81     ll = strlen(little);
  82     if( ll > (size_t)max ) return (char *)0;
  83     max -= (PRUint32)ll;
  84     max++;
  85
  86     for( ; max && *big; big++, max-- )
  87         if( *little == *big )
  88             if( 0 == strncmp(big, little, ll) )
  89                 return (char *)big;
  90
  91     return (char *)0;
  92 }
  93
  94 PR_IMPLEMENT(char *)
  95 PL_strnrstr(const char *big, const char *little, PRUint32 max)
  96 {
  97     const char *p;
  98     size_t ll;
  99
 100     if( ((const char *)0 == big) || ((const char *)0 == little) ) return (char *)0;
 101     if( ((char)0 == *big) || ((char)0 == *little) ) return (char *)0;
 102
 103     ll = strlen(little);
 104
 105     for( p = big; max && *p; p++, max-- )
 106         ;
 107
 108     p -= ll;
 109     if( p < big ) return (char *)0;
 110
 111     for( ; p >= big; p-- )
 112         if( *little == *p )
 113             if( 0 == strncmp(p, little, ll) )
 114                 return (char *)p;
 115
 116     return (char *)0;
 117 }