_fileno

Gets the file handle associated with a stream.

int_fileno(FILE*stream);

For additional compatibility information, see Compatibility in the Introduction.

Libraries

Return Value

_fileno returns the file handle. There is no error return. The result is undefined if stream does not specify an open file.

Parameter

stream

Pointer to FILE structure

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

Stream I/O Routines

See Also   _fdopen, _filelength, fopen, freopen