_mbccpy_s, _mbccpy_s_l

 

For the latest documentation on Visual Studio 2017 RC, see Visual Studio 2017 RC Documentation.

Copies one multibyte character from a string to another string. These versions of _mbccpy, _mbccpy_l have security enhancements, as described in Security Features in the CRT.

System_CAPS_ICON_important.jpg Important

This API cannot be used in applications that execute in the Windows Runtime. For more information, see CRT functions not supported with /ZW.

errno_t _mbccpy_s(  
   unsigned char *dest,  
   size_t buffSizeInBytes,  
   int * pCopied,  
   const unsigned char *src   
);  
errno_t _mbccpy_s_l(  
   unsigned char *dest,  
   size_t buffSizeInBytes,  
   int * pCopied,  
   const unsigned char *src,  
   locale_t locale  
);  
template <size_t size>  
errno_t _mbccpy_s(  
   unsigned char (&dest)[size],  
   int * pCopied,  
   const unsigned char *src   
); // C++ only  
template <size_t size>  
errno_t _mbccpy_s_l(  
   unsigned char (&dest)[size],  
   int * pCopied,  
   const unsigned char *src,  
   locale_t locale  
); // C++ only  

Parameters

[out] dest
Copy destination.

[in] buffSizeInBytes
Size of the destination buffer.

[out] pCopied
Filled with the number of bytes copied (1 or 2 if successful). Pass NULL if you don't care about the number.

[in] src
Multibyte character to copy.

[in] locale
Locale to use.

Zero if successful; an error code on failure. If src or dest is NULL, or if more than buffSizeinBytes bytes would be copied to dest, then the invalid parameter handler is invoked, as described in Parameter Validation. If execution is allowed to continue, the functions return EINVAL and errno is set to EINVAL.

The _mbccpy_s function copies one multibyte character from src to dest. If src does not point to the lead byte of a multibyte character as determined by an implicit call to _ismbblead, then the single byte that src points to is copied. If src points to a lead byte but the following byte is 0 and thus invalid, then 0 is copied to dest, errno is set to EILSEQ, and the function returns EILSEQ.

_mbccpy_s does not append a null terminator; however, if src points to a null character, then that null is copied to dest (this is just a regular single-byte copy).

The value in pCopied is filled with the number of bytes copied. Possible values are 1 and 2 if the operation is successful. If NULL is passed in, this parameter is ignored.

srccopied to destpCopiedReturn value
non-lead-bytenon-lead-byte10
0010
lead-byte followed by non-0lead-byte followed by non-020
lead-byte followed by 001EILSEQ

Note that the second row is just a special case of the first. Also note that the table assumes buffSizeInBytes >= pCopied.

_mbccpy_s uses the current locale for any locale-dependent behavior. _mbccpy_s_l is identical to _mbccpy_s except that _mbccpy_s_l uses the locale passed in for any locale-dependent behavior.

In C++, using these functions is simplified by template overloads; the overloads can infer buffer length automatically, eliminating the need to specify a size argument. For more information, see Secure Template Overloads.

Generic-Text Routine Mappings

Tchar.h routine_UNICODE and _MBCS not defined_MBCS defined_UNICODE defined
_tccpy_sMaps to macro or inline function._mbccpy_sMaps to macro or inline function.
RoutineRequired header
_mbccpy_s<mbstring.h>
_mbccpy_s_l<mbstring.h>

For more compatibility information, see Compatibility.

Locale
Interpretation of Multibyte-Character Sequences
_mbclen, mblen, _mblen_l

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