curl/lib/strequal.c

   1 /***************************************************************************
   2  *                                  _   _ ____  _
   3  *  Project                     ___| | | |  _ \| |
   4  *                             / __| | | | |_) | |
   5  *                            | (__| |_| |  _ <| |___
   6  *                             \___|\___/|_| \_\_____|
   7  *
   8  * Copyright (C) 1998 - 2007, Daniel Stenberg, <daniel@haxx.se>, et al.
   9  *
  10  * This software is licensed as described in the file COPYING, which
  11  * you should have received as part of this distribution. The terms
  12  * are also available at http://curl.haxx.se/docs/copyright.html.
  13  *
  14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
  15  * copies of the Software, and permit persons to whom the Software is
  16  * furnished to do so, under the terms of the COPYING file.
  17  *
  18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  19  * KIND, either express or implied.
  20  *
  21  * $Id: strequal.c,v 1.33 2007-11-07 09:21:36 bagder Exp $
  22  ***************************************************************************/
  23
  24 #ifndef _GNU_SOURCE
  25 /* glibc needs this to define the prototype for strcasestr */
  26 #define _GNU_SOURCE 1
  27 #endif
  28
  29 #include "setup.h"
  30
  31 #include <string.h>
  32 #include <ctype.h>
  33
  34 #ifdef HAVE_STRINGS_H
  35 #include <strings.h>
  36 #endif
  37
  38 #include "strequal.h"
  39
  40 #if defined(HAVE_STRCASECMP) && defined(__STRICT_ANSI__)
  41 /* this is for "-ansi -Wall -pedantic" to stop complaining! */
  42 extern int (strcasecmp)(const char *s1, const char *s2);
  43 extern int (strncasecmp)(const char *s1, const char *s2, size_t n);
  44 #endif
  45
  46 int curl_strequal(const char *first, const char *second)
  47 {
  48 #if defined(HAVE_STRCASECMP)
  49   return !(strcasecmp)(first, second);
  50 #elif defined(HAVE_STRCMPI)
  51   return !(strcmpi)(first, second);
  52 #elif defined(HAVE_STRICMP)
  53   return !(stricmp)(first, second);
  54 #else
  55   while(*first && *second) {
  56     if(toupper(*first) != toupper(*second)) {
  57       break;
  58     }
  59     first++;
  60     second++;
  61   }
  62   return toupper(*first) == toupper(*second);
  63 #endif
  64 }
  65
  66 int curl_strnequal(const char *first, const char *second, size_t max)
  67 {
  68 #if defined(HAVE_STRCASECMP)
  69   return !strncasecmp(first, second, max);
  70 #elif defined(HAVE_STRCMPI)
  71   return !strncmpi(first, second, max);
  72 #elif defined(HAVE_STRICMP)
  73   return !strnicmp(first, second, max);
  74 #else
  75   while(*first && *second && max) {
  76     if(toupper(*first) != toupper(*second)) {
  77       break;
  78     }
  79     max--;
  80     first++;
  81     second++;
  82   }
  83   if(0 == max)
  84     return 1; /* they are equal this far */
  85
  86   return toupper(*first) == toupper(*second);
  87 #endif
  88 }
  89
  90 /*
  91  * Curl_strcasestr() finds the first occurrence of the substring needle in the
  92  * string haystack.  The terminating `\0' characters are not compared. The
  93  * matching is done CASE INSENSITIVE, which thus is the difference between
  94  * this and strstr().
  95  */
  96 char *Curl_strcasestr(const char *haystack, const char *needle)
  97 {
  98 #if defined(HAVE_STRCASESTR)
  99   return strcasestr(haystack, needle);
 100 #else
 101   size_t nlen = strlen(needle);
 102   size_t hlen = strlen(haystack);
 103
 104   while(hlen-- >= nlen) {
 105     if(curl_strnequal(haystack, needle, nlen))
 106       return (char *)haystack;
 107     haystack++;
 108   }
 109   return NULL;
 110 #endif
 111 }
 112
 113 #ifndef HAVE_STRLCAT
 114 /*
 115  * The strlcat() function appends the NUL-terminated string src to the end
 116  * of dst. It will append at most size - strlen(dst) - 1 bytes, NUL-termi-
 117  * nating the result.
 118  *
 119  * The strlcpy() and strlcat() functions return the total length of the
 120  * string they tried to create.  For strlcpy() that means the length of src.
 121  * For strlcat() that means the initial length of dst plus the length of
 122  * src. While this may seem somewhat confusing it was done to make trunca-
 123  * tion detection simple.
 124  *
 125  *
 126  */
 127 size_t Curl_strlcat(char *dst, const char *src, size_t siz)
 128 {
 129   char *d = dst;
 130   const char *s = src;
 131   size_t n = siz;
 132   size_t dlen;
 133
 134   /* Find the end of dst and adjust bytes left but don't go past end */
 135   while(n-- != 0 && *d != '\0')
 136     d++;
 137   dlen = d - dst;
 138   n = siz - dlen;
 139
 140   if(n == 0)
 141     return(dlen + strlen(s));
 142   while(*s != '\0') {
 143     if(n != 1) {
 144       *d++ = *s;
 145       n--;
 146     }
 147     s++;
 148   }
 149   *d = '\0';
 150
 151   return(dlen + (s - src));     /* count does not include NUL */
 152 }
 153 #endif