_access, _waccess

Determine file-access permission.



Routine Required Header Optional Headers Compatibility
_access <io.h> <errno.h> Win 95, Win NT
_waccess <wchar.h> or <io.h> <errno.h> Win NT

For additional compatibility information, see Compatibility in the Introduction.


LIBC.LIB Single thread static library, retail version
LIBCMT.LIB Multithread static library, retail version
MSVCRT.LIB Import library for MSVCRT.DLL, retail version

Return Value

Each of these functions returns 0 if the file has the given mode. The function returns –1 if the named file does not exist or is not accessible in the given mode; in this case, errno is set as follows:


Access denied: file’s permission setting does not allow specified access.


Filename or path not found.



File or directory path


Permission setting


When used with files, the _access function determines whether the specified file exists and can be accessed as specified by the value of mode. When used with directories, _access determines only whether the specified directory exists; in Windows NT, all directories have read and write access.

mode Value Checks File For
00 Existence only
02 Write permission
04 Read permission
06 Read and write permission

_waccess is a wide-character version of _access; the path argument to _waccess is a wide-character string. _waccess and _access behave identically otherwise.

Generic-Text Routine Mappings

TCHAR.H Routine _UNICODE & _MBCS Not Defined _MBCS Defined _UNICODE Defined
_taccess _access _access _waccess


/* ACCESS.C: This example uses _access to check the
 * file named "ACCESS.C" to see if it exists and if
 * writing is allowed.

#include  <io.h>
#include  <stdio.h>
#include  <stdlib.h>

void main( void )
   /* Check for existence */
   if( (_access( "ACCESS.C", 0 )) != -1 )
      printf( "File ACCESS.C exists\n" );
      /* Check for write permission */
      if( (_access( "ACCESS.C", 2 )) != -1 )
         printf( "File ACCESS.C has write permission\n" );


File ACCESS.C exists
File ACCESS.C has write permission

File Handling Routines

See Also_chmod, _fstat, _open, _stat