fileno.3s (2010 09)

f
fileno(3S) fileno(3S)
NAME
fileno( ) - map stream pointer to file descriptor
SYNOPSIS
#include <stdio.h>
int fileno(FILE *stream);
Obsolescent Interfaces
int fileno_unlocked(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.
Obsolescent Interfaces
fileno_unlocked()
map stream pointer to file descriptor
APPLICATION USAGE
fileno_unlocked()
is an obsolescent interface supported only for compatibility with existing DCE
applications. New multithreaded applications should use
fileno().
RETURN VALUE
Upon error,
fileno() and fileno_unlocked()
return -1.
SEE ALSO
open(2), flockfile(3S), fopen(3S), thread_safety(5).
STANDARDS CONFORMANCE
fileno(): AES, SVID2, SVID3, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1