112 lines
3.2 KiB
C
112 lines
3.2 KiB
C
/***
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*_mbslen_s.c - Return number of multibyte characters in a multibyte string
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*
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* Copyright (c) Microsoft Corporation. All rights reserved.
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*
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*Purpose:
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* Return number of multibyte characters in a multibyte string
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* excluding the terminal null. Locale-dependent.
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*
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*******************************************************************************/
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#include <cruntime.h>
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#include <stdlib.h>
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#include <ctype.h>
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#include <locale.h>
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#include <dbgint.h>
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#include <internal.h>
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#include <mtdll.h>
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#include <setlocal.h>
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/***
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*_mbstrnlen - Return number of multibyte characters in a multibyte string
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*
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*Purpose:
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* Return number of multibyte characters in a multibyte string
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* excluding the terminal null. Locale-dependent.
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*
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*Entry:
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* char *s = string
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* size_t maxsize
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*
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*Exit:
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* Returns the number of multibyte characters in the string, or
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* (size_t)-1 if the string contains an invalid multibyte character and errno
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* is set to EILSEQ.
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* Only the first sizeInBytes bytes of the string are inspected: if the null
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* terminator is not found, sizeInBytes is returned.
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* If the string is null terminated in sizeInBytes bytes, the return value
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* will always be less than sizeInBytes.
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* If something goes wrong, (size_t)-1 is returned and errno is set to EINVAL.
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*
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*Exceptions:
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* Input parameters are validated. Refer to the validation section of the function.
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*
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*******************************************************************************/
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size_t __cdecl _mbstrnlen_l(
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const char *s,
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size_t sizeInBytes,
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_locale_t plocinfo
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)
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{
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size_t n, size;
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/* validation section */
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_VALIDATE_RETURN(s != NULL, EINVAL, (size_t)-1);
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_VALIDATE_RETURN(sizeInBytes <= INT_MAX, EINVAL, (size_t)-1);
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_LocaleUpdate _loc_update(plocinfo);
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_ASSERTE (_loc_update.GetLocaleT()->locinfo->mb_cur_max == 1 || _loc_update.GetLocaleT()->locinfo->mb_cur_max == 2);
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if ( _loc_update.GetLocaleT()->locinfo->mb_cur_max == 1 )
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/* handle single byte character sets */
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return (int)strnlen(s, sizeInBytes);
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/* verify all valid MB chars */
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if ( MultiByteToWideChar( _loc_update.GetLocaleT()->locinfo->lc_codepage,
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MB_PRECOMPOSED | MB_ERR_INVALID_CHARS,
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s,
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(int)sizeInBytes,
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NULL,
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0 ) == 0 )
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{
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/* bad MB char */
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errno = EILSEQ;
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return (size_t)-1;
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}
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/* count MB chars */
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/* Note that sizeInBytes here is the number of bytes, not mb characters! */
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for (n = 0, size = 0; size < sizeInBytes && *s; n++, s++, size++)
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{
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if ( _isleadbyte_l((unsigned char)*s, _loc_update.GetLocaleT()) )
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{
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size++;
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if (size >= sizeInBytes)
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{
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break;
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}
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if (*++s == '\0')
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{
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break;
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}
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}
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}
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return (size >= sizeInBytes ? sizeInBytes : n);
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}
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size_t __cdecl _mbstrnlen(
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const char *s,
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size_t maxsize
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)
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{
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return _mbstrnlen_l(s, maxsize, NULL);
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}
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