fileno - get file descriptor

Syntax

#include <stdio.h> int fileno(FILE *stream);

Description fileno() returns the integer file descriptor associated with the stream pointed to by

	stream.
Return val.	int value -1	if successful. Value of the file descriptor associated with stream. if an error occurs; errno is set to indicate the error.
Errors	fileno() will fail if: EABDF       stream is not a valid stream.
Notes	The program environment determines whether fileno() is executed for a BS2000 or POSIX file.
See also	fdopen(), fopen(), stdin(), stdio.h, section “Interaction of file descriptors andstreams”.