NAME

fileno − map stream pointer to file descriptor

SYNOPSIS

#include <stdio.h>

int fileno (stream)

FILE
∗stream;

DESCRIPTION

Fileno returns the integer file descriptor associated with the named stream; see open(2).

The following symbolic values in <unistd.h> define the file descriptors associated with stdin, stdout, and stderr when a program is started :

STDIN_FILENO Value of zero for standard input, stdin. 

STDOUT_FILENO
Value of 1 for standard output, stdout. 

STDERR_FILENO
Value of 2 for standard error, stderr. 

DIAGNOSTICS

Upon error, fileno will return a -1. 

SEE ALSO

open(2), fopen(3S). 

STANDARDS CONFORMANCE

fileno: SVID2, XPG2, XPG3, POSIX.1, FIPS 151-1

Hewlett-Packard Company  —  HP-UX Release 7.0: Sept 1989