_strdup_dbg, _wcsdup_dbg

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06/05/2017

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The latest version of this topic can be found at _strdup_dbg, _wcsdup_dbg.

Versions of _strdup and _wcsdup that use the debug version of malloc.

Syntax

char *_strdup_dbg(  
   const char *strSource,  
   int blockType,  
   const char *filename,  
   int linenumber   
);  
wchar_t *_wcsdup_dbg(  
   const wchar_t *strSource,  
   int blockType,  
   const char *filename,  
   int linenumber   
);

Parameters

strSource
Null-terminated source string.

blockType
Requested type of memory block: _CLIENT_BLOCK or _NORMAL_BLOCK.

filename
Pointer to name of source file that requested allocation operation or NULL.

linenumber
Line number in source file where allocation operation was requested or NULL.

Return Value

Each of these functions returns a pointer to the storage location for the copied string or NULL if storage cannot be allocated.

Remarks

The _strdup_dbg and _wcsdup_dbg functions are identical to _strdup and _wcsdup except that, when _DEBUG is defined, these functions use the debug version of malloc, _malloc_dbg, to allocate memory for the duplicated string. For information on the debugging features of _malloc_dbg, see _malloc_dbg.

You do not need to call these functions explicitly in most cases. Instead, you can define the flag _CRTDBG_MAP_ALLOC. When _CRTDBG_MAP_ALLOC is defined, calls to _strdup and _wcsdup are remapped to _strdup_dbg and _wcsdup_dbg, respectively, with the blockType set to _NORMAL_BLOCK. Thus, you do not need to call these functions explicitly unless you want to mark the heap blocks as _CLIENT_BLOCK. For more information on block types, see Types of blocks on the debug heap.

Generic-Text Routine Mappings

TCHAR.H routine	_UNICODE & _MBCS not defined	_MBCS defined	_UNICODE defined
`_tcsdup_dbg`	`_strdup_dbg`	`_mbsdup`	`_wcsdup_dbg`

Requirements

Routine	Required header
`_strdup_dbg`, `_wcsdup_dbg`	<crtdbg.h>

For additional compatibility information, see Compatibility in the Introduction.

Libraries

All debug versions of the C run-time libraries.

.NET Framework Equivalent

System::String::Clone

共用方式為