StdLib/LibC/String/Comparison.c

   1 /** @file
   2     Comparison Functions for <string.h>.
   3
   4   Copyright (c) 2010, Intel Corporation. All rights reserved.<BR>
   5   This program and the accompanying materials are licensed and made available under
   6   the terms and conditions of the BSD License that accompanies this distribution.
   7   The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php.
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12 **/
  13 #include  <Uefi.h>
  14 #include  <Library/BaseLib.h>
  15 #include  <Library/BaseMemoryLib.h>
  16
  17 #include  <LibConfig.h>
  18
  19 #include  <ctype.h>
  20 #include  <string.h>
  21
  22 /** The memcmp function compares the first n characters of the object pointed
  23     to by s1 to the first n characters of the object pointed to by s2.
  24
  25     @return   The memcmp function returns an integer greater than, equal to, or
  26               less than zero, accordingly as the object pointed to by s1 is
  27               greater than, equal to, or less than the object pointed to by s2.
  28 **/
  29 int       memcmp(const void *s1, const void *s2, size_t n)
  30 {
  31   return (int)CompareMem( s1, s2, n);
  32 }
  33
  34 /** The strcmp function compares the string pointed to by s1 to the string
  35     pointed to by s2.
  36
  37     @return   The strcmp function returns an integer greater than, equal to, or
  38               less than zero, accordingly as the string pointed to by s1 is
  39               greater than, equal to, or less than the string pointed to by s2.
  40 **/
  41 int       strcmp(const char *s1, const char *s2)
  42 {
  43   return (int)AsciiStriCmp( s1, s2);
  44 }
  45
  46 /** The strcoll function compares the string pointed to by s1 to the string
  47     pointed to by s2, both interpreted as appropriate to the LC_COLLATE
  48     category of the current locale.
  49
  50     @return   The strcoll function returns an integer greater than, equal to,
  51               or less than zero, accordingly as the string pointed to by s1 is
  52               greater than, equal to, or less than the string pointed to by s2
  53               when both are interpreted as appropriate to the current locale.
  54 **/
  55 int       strcoll(const char *s1, const char *s2)
  56 {
  57   /* LC_COLLATE is unimplemented, hence always "C" */
  58   return (strcmp(s1, s2));
  59 }
  60
  61 /** The strncmp function compares not more than n characters (characters that
  62     follow a null character are not compared) from the array pointed to by s1
  63     to the array pointed to by s2.
  64
  65     @return   The strncmp function returns an integer greater than, equal to,
  66               or less than zero, accordingly as the possibly null-terminated
  67               array pointed to by s1 is greater than, equal to, or less than
  68               the possibly null-terminated array pointed to by s2.
  69 **/
  70 int       strncmp(const char *s1, const char *s2, size_t n)
  71 {
  72   return (int)AsciiStrnCmp( s1, s2, n);
  73 }
  74
  75 /** The strxfrm function transforms the string pointed to by s2 and places the
  76     resulting string into the array pointed to by s1. The transformation is
  77     such that if the strcmp function is applied to two transformed strings, it
  78     returns a value greater than, equal to, or less than zero, corresponding to
  79     the result of the strcoll function applied to the same two original
  80     strings. No more than n characters are placed into the resulting array
  81     pointed to by s1, including the terminating null character. If n is zero,
  82     s1 is permitted to be a null pointer. If copying takes place between
  83     objects that overlap, the behavior is undefined.
  84
  85     @return   The strxfrm function returns the length of the transformed string
  86               (not including the terminating null character). If the value
  87               returned is n or more, the contents of the array pointed to by s1
  88               are indeterminate.
  89 **/
  90 size_t    strxfrm(char * __restrict s1, const char * __restrict s2, size_t n)
  91 {
  92   size_t srclen, copysize;
  93
  94   /*
  95   * Since locales are unimplemented, this is just a copy.
  96   */
  97   srclen = strlen(s2);
  98   if (n != 0) {
  99     copysize = srclen < n ? srclen : n - 1;
 100     (void)memcpy(s1, s2, copysize);
 101     s1[copysize] = 0;
 102   }
 103   return (srclen);
 104 }
 105
 106 /** Case agnostic string comparison for NetBSD compatibility. **/
 107 int
 108 strcasecmp(const char *s1, const char *s2)
 109 {
 110   const unsigned char *us1 = (const unsigned char *)s1,
 111   *us2 = (const unsigned char *)s2;
 112   int Difference;
 113
 114   while ( 0 == ( Difference = tolower(*us1) - tolower(*us2))) {
 115     if (*us1 == 0) {
 116     return (0);
 117     }
 118     us1 += 1;
 119     us2 += 1;
 120   }
 121   return Difference;
 122 }
 123