Name

clearerr, feof, ferror, fileno — check and reset stream status

Synopsis

#include <stdio.h>
void clearerr( FILE *stream);
 
int feof( FILE *stream);
 
int ferror( FILE *stream);
 
int fileno( FILE *stream);
 
[Note] Note
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
fileno():
_POSIX_C_SOURCE >= 1 || _XOPEN_SOURCE || _POSIX_SOURCE

DESCRIPTION

The function clearerr() clears the end-of-file and error indicators for the stream pointed to by stream.

The function feof() tests the end-of-file indicator for the stream pointed to by stream, returning nonzero if it is set. The end-of-file indicator can only be cleared by the function clearerr().

The function ferror() tests the error indicator for the stream pointed to by stream, returning nonzero if it is set. The error indicator can only be reset by the clearerr() function.

The function fileno() examines the argument stream and returns its integer descriptor.

For nonlocking counterparts, see unlocked_stdio(3).

ERRORS

These functions should not fail and do not set the external variable errno. (However, in case fileno() detects that its argument is not a valid stream, it must return −1 and set errno to EBADF.)

CONFORMING TO

The functions clearerr(), feof(), and ferror() conform to C89 and C99.

SEE ALSO

open(2), fdopen(3), stdio(3), unlocked_stdio(3)

COLOPHON

This page is part of release 3.24 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.


  Copyright (c) 1990, 1991 The Regents of the University of California.
All rights reserved.

This code is derived from software contributed to Berkeley by
Chris Torek and the American National Standards Committee X3,
on Information Processing Systems.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
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   documentation and/or other materials provided with the distribution.
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   must display the following acknowledgement:
This product includes software developed by the University of
California, Berkeley and its contributors.
4. Neither the name of the University nor the names of its contributors
   may be used to endorse or promote products derived from this software
   without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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    (#)ferror.3 6.8 (Berkeley) 6/29/91


Converted for Linux, Mon Nov 29 14:24:40 1993, faithcs.unc.edu
Added remark on EBADF for fileno, aeb, 2001-03-22