_fileno
This is preliminary documentation and subject to change.
_fileno
Gets the file handle associated with a stream.
Function | Required Header |
---|---|
_fileno | <stdio.h> |
int _fileno( FILE *stream );
Parameters
- stream
Pointer to FILE structure
Libraries
All versions of the C run-time libraries.
Return Values
_fileno returns the file handle. There is no error return. The result is undefined if stream does not specify an open file.
Remarks
The _fileno routine returns the file handle currently associated with stream. This routine is implemented both as a function and as a macro. For details on choosing either implementation, see Choosing Between Functions and Macros.
Example
/* FILENO.C: This program uses _fileno to obtain
* the file handle for some standard C streams.
*/
#include <stdio.h>
void main( void )
{
printf( "The file handle for stdin is %d\n", _fileno( stdin ) );
printf( "The file handle for stdout is %d\n", _fileno( stdout ) );
printf( "The file handle for stderr is %d\n", _fileno( stderr ) );
}
Output
The file handle for stdin is 0
The file handle for stdout is 1
The file handle for stderr is 2
See Also