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Reactos
1/***
2*mbsnbcmp.c - Compare n bytes of two MBCS strings
3*
4* Copyright (c) Microsoft Corporation. All rights reserved.
5*
6*Purpose:
7* Compare n bytes of two MBCS strings
8*
9*******************************************************************************/
10#ifndef _MBCS
11 #error This file should only be compiled with _MBCS defined
12#endif
13
14#include <corecrt_internal_mbstring.h>
15#include <locale.h>
16
17#pragma warning(disable:__WARNING_POTENTIAL_BUFFER_OVERFLOW_NULLTERMINATED) // 26018
18
19/***
20*int mbsnbcmp(s1, s2, n) - Compare n bytes of two MBCS strings
21*
22*Purpose:
23* Compares up to n bytes of two strings for ordinal order.
24*
25* UTF-8 and SBCS are merely compared in byte order.
26* DBCS are compared by codepoint to ensure double byte chars sort last
27*
28*Entry:
29* unsigned char *s1, *s2 = strings to compare
30* size_t n = maximum number of bytes to compare
31*
32*Exit:
33* Returns <0 if s1 < s2
34* Returns 0 if s1 == s2
35* Returns >0 if s1 > s2
36* Returns _NLSCMPERROR is something went wrong
37*
38*Exceptions:
39* Input parameters are validated. Refer to the validation section of the function.
40*
41*******************************************************************************/
42
43extern "C" int __cdecl _mbsnbcmp_l(
44 const unsigned char *s1,
45 const unsigned char *s2,
46 size_t n,
47 _locale_t plocinfo
48 )
49{
50 unsigned short c1, c2;
51
52 if (n==0)
53 return(0);
54
55 _LocaleUpdate _loc_update(plocinfo);
56
57 if (_loc_update.GetLocaleT()->mbcinfo->ismbcodepage == 0)
58 return strncmp((const char *)s1, (const char *)s2, n);
59
60 /* validation section */
61 _VALIDATE_RETURN(s1 != nullptr, EINVAL, _NLSCMPERROR);
62 _VALIDATE_RETURN(s2 != nullptr, EINVAL, _NLSCMPERROR);
63
64 while (n--) {
65
66 c1 = *s1++;
67 if ( _ismbblead_l(c1, _loc_update.GetLocaleT()) )
68 {
69 if (n==0)
70 {
71 c1 = 0; /* 'naked' lead - end of string */
72 c2 = _ismbblead_l(*s2, _loc_update.GetLocaleT()) ? 0 : *s2;
73 goto test;
74 }
75 c1 = ( (*s1 == '\0') ? 0 : ((c1<<8) | *s1++) );
76 }
77
78 c2 = *s2++;
79 if ( _ismbblead_l(c2, _loc_update.GetLocaleT()) )
80 {
81 if (n==0)
82 {
83 c2 = 0; /* 'naked' lead - end of string */
84 goto test;
85 }
86 --n;
87 c2 = ( (*s2 == '\0') ? 0 : ((c2<<8) | *s2++) );
88 }
89test:
90 if (c1 != c2)
91 return( (c1 > c2) ? 1 : -1);
92
93 if (c1 == 0)
94 return(0);
95 }
96
97 return(0);
98}
99
100extern "C" int (__cdecl _mbsnbcmp)(
101 const unsigned char *s1,
102 const unsigned char *s2,
103 size_t n
104 )
105{
106 return _mbsnbcmp_l(s1, s2, n, nullptr);
107}