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Reactos
1/***
2*strnicmp.cpp - compare n chars of strings, ignoring case
3*
4* Copyright (c) Microsoft Corporation. All rights reserved.
5*
6*Purpose:
7* defines _strnicmp() - Compares at most n characters of two strings,
8* without regard to case.
9*
10*******************************************************************************/
11#include <corecrt_internal.h>
12#include <ctype.h>
13#include <locale.h>
14#include <string.h>
15
16/***
17*int _strnicmp(lhs, rhs, count) - compares count char of strings, ignore case
18*
19*Purpose:
20* Compare the two strings for ordinal order. Stops the comparison
21* when the following occurs: (1) strings differ, (2) the end of the
22* strings is reached, or (3) count characters have been compared.
23* For the purposes of the comparison, upper case characters are
24* converted to lower case.
25*
26*Entry:
27* char *lhs, *rhs - strings to compare
28* size_t count - maximum number of characters to compare
29*
30*Exit:
31* returns <0 if lhs < rhs
32* returns 0 if lhs == rhs
33* returns >0 if lhs > rhs
34* Returns _NLSCMPERROR if something went wrong
35*
36*Exceptions:
37* Input parameters are validated. Refer to the validation section of the function.
38*
39*******************************************************************************/
40
41extern "C" int __cdecl _strnicmp_l (
42 char const * const lhs,
43 char const * const rhs,
44 size_t const count,
45 _locale_t const plocinfo
46 )
47{
48 /* validation section */
49 _VALIDATE_RETURN(lhs != nullptr, EINVAL, _NLSCMPERROR);
50 _VALIDATE_RETURN(rhs != nullptr, EINVAL, _NLSCMPERROR);
51 _VALIDATE_RETURN(count <= INT_MAX, EINVAL, _NLSCMPERROR);
52
53 if (count == 0)
54 {
55 return 0;
56 }
57
58 unsigned char const * lhs_ptr = reinterpret_cast<unsigned char const *>(lhs);
59 unsigned char const * rhs_ptr = reinterpret_cast<unsigned char const *>(rhs);
60
61 _LocaleUpdate _loc_update(plocinfo);
62
63 int result;
64 int lhs_value;
65 int rhs_value;
66 size_t remaining = count;
67 do
68 {
69 lhs_value = _tolower_fast_internal(*lhs_ptr++, _loc_update.GetLocaleT());
70 rhs_value = _tolower_fast_internal(*rhs_ptr++, _loc_update.GetLocaleT());
71 result = lhs_value - rhs_value;
72 }
73 while (result == 0 && lhs_value != 0 && --remaining != 0);
74
75 return result;
76}
77
78
79#if !defined(_M_IX86) || defined(_M_HYBRID_X86_ARM64)
80
81extern "C" int __cdecl __ascii_strnicmp (
82 char const * const lhs,
83 char const * const rhs,
84 size_t const count
85 )
86{
87 if (count == 0)
88 {
89 return 0;
90 }
91
92 unsigned char const * lhs_ptr = reinterpret_cast<unsigned char const *>(lhs);
93 unsigned char const * rhs_ptr = reinterpret_cast<unsigned char const *>(rhs);
94
95 int result;
96 int lhs_value;
97 int rhs_value;
98 size_t remaining = count;
99 do
100 {
101 lhs_value = __ascii_tolower(*lhs_ptr++);
102 rhs_value = __ascii_tolower(*rhs_ptr++);
103 result = lhs_value - rhs_value;
104 }
105 while (result == 0 && lhs_value != 0 && --remaining != 0);
106
107 return result;
108}
109
110#endif /* !_M_IX86 || _M_HYBRID_X86_ARM64 */
111
112extern "C" int __cdecl _strnicmp (
113 char const * const lhs,
114 char const * const rhs,
115 size_t const count
116 )
117{
118 if (!__acrt_locale_changed())
119 {
120 /* validation section */
121 _VALIDATE_RETURN(lhs != nullptr, EINVAL, _NLSCMPERROR);
122 _VALIDATE_RETURN(rhs != nullptr, EINVAL, _NLSCMPERROR);
123 _VALIDATE_RETURN(count <= INT_MAX, EINVAL, _NLSCMPERROR);
124
125 return __ascii_strnicmp(lhs, rhs, count);
126 }
127
128 return _strnicmp_l(lhs, rhs, count, nullptr);
129}