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.\" $DragonFly: src/lib/libc/stdio/ferror.3,v 1.2 2003/06/17 04:26:45 dillon Exp $ 39.\" 40.Dd April 19, 1994 41.Dt FERROR 3 42.Os 43.Sh NAME 44.Nm clearerr , 45.Nm feof , 46.Nm ferror , 47.Nm fileno 48.Nd check and reset stream status 49.Sh LIBRARY 50.Lb libc 51.Sh SYNOPSIS 52.In stdio.h 53.Ft void 54.Fn clearerr "FILE *stream" 55.Ft int 56.Fn feof "FILE *stream" 57.Ft int 58.Fn ferror "FILE *stream" 59.Ft int 60.Fn fileno "FILE *stream" 61.Sh DESCRIPTION 62The function 63.Fn clearerr 64clears the end-of-file and error indicators for the stream pointed 65to by 66.Fa stream . 67.Pp 68The function 69.Fn feof 70tests the end-of-file indicator for the stream pointed to by 71.Fa stream , 72returning non-zero if it is set. 73The end-of-file indicator can only be cleared by the function 74.Fn clearerr . 75.Pp 76The function 77.Fn ferror 78tests the error indicator for the stream pointed to by 79.Fa stream , 80returning non-zero if it is set. 81The error indicator can only be reset by the 82.Fn clearerr 83function. 84.Pp 85The function 86.Fn fileno 87examines the argument 88.Fa stream 89and returns its integer descriptor. 90.Sh ERRORS 91These functions should not fail and do not set the external 92variable 93.Va errno . 94.Sh SEE ALSO 95.Xr open 2 , 96.Xr fdopen 3 , 97.Xr stdio 3 98.Sh STANDARDS 99The functions 100.Fn clearerr , 101.Fn feof , 102and 103.Fn ferror 104conform to 105.St -isoC . 106