1.\" Copyright (c) 1990, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" Chris Torek and the American National Standards Committee X3, 6.\" on Information Processing Systems. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. All advertising materials mentioning features or use of this software 17.\" must display the following acknowledgement: 18.\" This product includes software developed by the University of 19.\" California, Berkeley and its contributors. 20.\" 4. Neither the name of the University nor the names of its contributors 21.\" may be used to endorse or promote products derived from this software 22.\" without specific prior written permission. 23.\" 24.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34.\" SUCH DAMAGE. 35.\" 36.\" @(#)ferror.3 8.2 (Berkeley) 4/19/94 37.\" $FreeBSD: src/lib/libc/stdio/ferror.3,v 1.3.2.4 2001/12/14 18:33:57 ru Exp $ 38.\" 39.Dd April 19, 1994 40.Dt FERROR 3 41.Os 42.Sh NAME 43.Nm clearerr , 44.Nm feof , 45.Nm ferror , 46.Nm fileno 47.Nd check and reset stream status 48.Sh LIBRARY 49.Lb libc 50.Sh SYNOPSIS 51.In stdio.h 52.Ft void 53.Fn clearerr "FILE *stream" 54.Ft int 55.Fn feof "FILE *stream" 56.Ft int 57.Fn ferror "FILE *stream" 58.Ft int 59.Fn fileno "FILE *stream" 60.Sh DESCRIPTION 61The function 62.Fn clearerr 63clears the end-of-file and error indicators for the stream pointed 64to by 65.Fa stream . 66.Pp 67The function 68.Fn feof 69tests the end-of-file indicator for the stream pointed to by 70.Fa stream , 71returning non-zero if it is set. 72The end-of-file indicator can only be cleared by the function 73.Fn clearerr . 74.Pp 75The function 76.Fn ferror 77tests the error indicator for the stream pointed to by 78.Fa stream , 79returning non-zero if it is set. 80The error indicator can only be reset by the 81.Fn clearerr 82function. 83.Pp 84The function 85.Fn fileno 86examines the argument 87.Fa stream 88and returns its integer descriptor. 89.Sh ERRORS 90These functions should not fail and do not set the external 91variable 92.Va errno . 93.Sh SEE ALSO 94.Xr open 2 , 95.Xr fdopen 3 , 96.Xr stdio 3 97.Sh STANDARDS 98The functions 99.Fn clearerr , 100.Fn feof , 101and 102.Fn ferror 103conform to 104.St -isoC . 105