1.\" $NetBSD: ferror.3,v 1.8 2002/02/07 07:00:24 ross Exp $ 2.\" 3.\" Copyright (c) 1990, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" Chris Torek and the American National Standards Committee X3, 8.\" on Information Processing Systems. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. All advertising materials mentioning features or use of this software 19.\" must display the following acknowledgement: 20.\" This product includes software developed by the University of 21.\" California, Berkeley and its contributors. 22.\" 4. Neither the name of the University nor the names of its contributors 23.\" may be used to endorse or promote products derived from this software 24.\" without specific prior written permission. 25.\" 26.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36.\" SUCH DAMAGE. 37.\" 38.\" @(#)ferror.3 8.2 (Berkeley) 4/19/94 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.Fd #include \*[Lt]stdio.h\*[Gt] 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 stdio 3 97.Sh STANDARDS 98The functions 99.Fn clearerr , 100.Fn feof , 101and 102.Fn ferror 103conform to 104.St -ansiC . 105The function 106.Fn fileno 107conforms to 108.St -p1003.1-90 . 109