_getdcwd_dbg, _wgetdcwd_dbg

项目
12/18/2017

The latest version of this topic can be found at _getdcwd_dbg, _wgetdcwd_dbg.

Debug versions of the _getdcwd, _wgetdcwd functions (only available during debug).

Syntax

char *_getdcwd_dbg(  
   int drive,  
   char *buffer,  
   int maxlen,  
   int blockType,  
   const char *filename,  
   int linenumber   
);  
wchar_t *_wgetdcwd_dbg(  
   int drive,  
   wchar_t *buffer,  
   int maxlen,  
   int blockType,  
   const char *filename,  
   int linenumber   
);

Parameters

drive
Name of the disk drive.

buffer
Storage location for the path.

maxlen
Maximum length of the path in characters: char for _getdcwd_dbgand wchar_tfor _wgetdcwd_dbg.

blockType
Requested type of the memory block: _CLIENT_BLOCKor _NORMAL_BLOCK.

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

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

Return Value

Returns a pointer to buffer. A NULL return value indicates an error, and errno is set either to ENOMEM, indicating that there is insufficient memory to allocate maxlen bytes (when a NULL argument is given as buffer), or to ERANGE, indicating that the path is longer than maxlen characters. For more information, see errno, _doserrno, _sys_errlist, and _sys_nerr.

Remarks

The _getdcwd_dbg and _wgetdcwd_dbg functions are identical to _getdcwd and _wgetdcwd except that, when _DEBUG is defined, these functions use the debug version of malloc and _malloc_dbg to allocate memory if NULL is passed as the buffer parameter. For more information, see _malloc_dbg.

You do not need to call these functions explicitly in most cases. Instead, you can define the _CRTDBG_MAP_ALLOC flag. When _CRTDBG_MAP_ALLOC is defined, calls to _getdcwd and _wgetdcwd are remapped to _getdcwd_dbg and _wgetdcwd_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, see Types of Blocks on the Debug Heap.

Generic-Text Routine Mappings

Tchar.h routine	_UNICODE and _MBCS not defined	_MBCS defined	_UNICODE defined
`_tgetdcwd_dbg`	`_getdcwd_dbg`	`_getdcwd_dbg`	`_wgetdcwd_dbg`

Requirements

Routine	Required header
`_getdcwd_dbg`	<crtdbg.h>
`_wgetdcwd_dbg`	<crtdbg.h>

For more compatibility information, see Compatibility in the Introduction.

.NET Framework Equivalent

Environment.CurrentDirectory

通过