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1/***
2*mbsrchr.c - Search for last occurence of character (MBCS)
3*
4* Copyright (c) Microsoft Corporation. All rights reserved.
5*
6*Purpose:
7* Search for last occurence of character (MBCS)
8*
9*
10*******************************************************************************/
11#ifndef _MBCS
12 #error This file should only be compiled with _MBCS defined
13#endif
14
15#include <corecrt_internal_mbstring.h>
16#include <locale.h>
17#include <stddef.h>
18#include <string.h>
19
20#pragma warning(disable:__WARNING_POTENTIAL_BUFFER_OVERFLOW_NULLTERMINATED) // 26018
21
22/***
23* _mbsrchr - Search for last occurence of character (MBCS)
24*
25*Purpose:
26* Find the last occurrence of the specified character in
27* the supplied string. Handles MBCS chars/strings correctly.
28*
29*Entry:
30* unsigned char *str = string to search in
31* unsigned int c = character to search for
32*
33*Exit:
34* returns pointer to last occurrence of c in str
35* returns nullptr if c not found
36*
37*Exceptions:
38* Input parameters are validated. Refer to the validation section of the function.
39*
40*******************************************************************************/
41
42extern "C" _CONST_RETURN unsigned char * __cdecl _mbsrchr_l(
43 const unsigned char *str,
44 unsigned int c,
45 _locale_t plocinfo
46 )
47{
48 char *r = nullptr;
49 unsigned int cc;
50 _LocaleUpdate _loc_update(plocinfo);
51
52 /* validation section */
53 _VALIDATE_RETURN(str != nullptr, EINVAL, 0);
54
55 if (_loc_update.GetLocaleT()->mbcinfo->ismbcodepage == 0)
56 return (_CONST_RETURN unsigned char *)strrchr((const char *)str, c);
57
58 do {
59 cc = *str;
60 if ( _ismbblead_l(cc, _loc_update.GetLocaleT()) ) {
61 if(*++str) {
62 if (c == ((cc<<8)|*str))
63 r = (char *)str - 1;
64 }
65 else if(!r)
66 /* return pointer to '\0' */
67 r = (char *)str;
68 }
69 else if (c == cc)
70 r = (char *)str;
71 }
72 while (*str++);
73
74 return((_CONST_RETURN unsigned char *)r);
75}
76
77extern "C" _CONST_RETURN unsigned char * (__cdecl _mbsrchr)(
78 const unsigned char *str,
79 unsigned int c
80 )
81{
82 return _mbsrchr_l(str, c, nullptr);
83}