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Gets the file handle associated with a stream.
int_fileno(FILE*stream);
| Function | Required Header | Compatibility |
| _fileno | <stdio.h> | Win 95, Win NT |
For additional compatibility information, see Compatibility in the Introduction.
Libraries
| 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
_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
See Also _fdopen, _filelength, fopen, freopen