81 lines
2.3 KiB
C
81 lines
2.3 KiB
C
/*
|
|
* Copyright (c) 1990 The Regents of the University of California.
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms are permitted
|
|
* provided that the above copyright notice and this paragraph are
|
|
* duplicated in all such forms and that any documentation,
|
|
* advertising materials, and other materials related to such
|
|
* distribution and use acknowledge that the software was developed
|
|
* by the University of California, Berkeley. The name of the
|
|
* University may not be used to endorse or promote products derived
|
|
* from this software without specific prior written permission.
|
|
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
|
|
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
|
|
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
|
|
*/
|
|
|
|
/*
|
|
FUNCTION
|
|
<<fileno>>, <<fileno_unlocked>>---return file descriptor associated with stream
|
|
|
|
INDEX
|
|
fileno
|
|
INDEX
|
|
fileno_unlocked
|
|
|
|
SYNOPSIS
|
|
#include <stdio.h>
|
|
int fileno(FILE *<[fp]>);
|
|
|
|
#define _BSD_SOURCE
|
|
#include <stdio.h>
|
|
int fileno_unlocked(FILE *<[fp]>);
|
|
|
|
DESCRIPTION
|
|
You can use <<fileno>> to return the file descriptor identified by <[fp]>.
|
|
|
|
<<fileno_unlocked>> is a non-thread-safe version of <<fileno>>.
|
|
<<fileno_unlocked>> may only safely be used within a scope
|
|
protected by flockfile() (or ftrylockfile()) and funlockfile(). This
|
|
function may safely be used in a multi-threaded program if and only
|
|
if they are called while the invoking thread owns the (FILE *)
|
|
object, as is the case after a successful call to the flockfile() or
|
|
ftrylockfile() functions. If threads are disabled, then
|
|
<<fileno_unlocked>> is equivalent to <<fileno>>.
|
|
|
|
RETURNS
|
|
<<fileno>> returns a non-negative integer when successful.
|
|
If <[fp]> is not an open stream, <<fileno>> returns -1.
|
|
|
|
PORTABILITY
|
|
<<fileno>> is not part of ANSI C.
|
|
POSIX requires <<fileno>>.
|
|
|
|
<<fileno_unlocked>> is a BSD extension also provided by GNU libc.
|
|
|
|
Supporting OS subroutines required: none.
|
|
*/
|
|
|
|
#include <_ansi.h>
|
|
#include <stdio.h>
|
|
#include <errno.h>
|
|
#include "local.h"
|
|
|
|
int
|
|
fileno (FILE * f)
|
|
{
|
|
int result;
|
|
CHECK_INIT (_REENT, f);
|
|
_newlib_flockfile_start (f);
|
|
if (f->_flags)
|
|
result = __sfileno (f);
|
|
else
|
|
{
|
|
result = -1;
|
|
_REENT->_errno = EBADF;
|
|
}
|
|
_newlib_flockfile_end (f);
|
|
return result;
|
|
}
|