1.\" $OpenBSD: ferror.3,v 1.5 2000/04/20 01:39:31 aaron 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.Dd April 19, 1994 39.Dt FERROR 3 40.Os 41.Sh NAME 42.Nm clearerr , 43.Nm feof , 44.Nm ferror , 45.Nm fileno 46.Nd check and reset stream status 47.Sh SYNOPSIS 48.Fd #include <stdio.h> 49.Ft void 50.Fn clearerr "FILE *stream" 51.Ft int 52.Fn feof "FILE *stream" 53.Ft int 54.Fn ferror "FILE *stream" 55.Ft int 56.Fn fileno "FILE *stream" 57.Sh DESCRIPTION 58The function 59.Fn clearerr 60clears the end-of-file and error indicators for the stream pointed to by 61.Fa stream . 62.Pp 63The function 64.Fn feof 65tests the end-of-file indicator for the stream pointed to by 66.Fa stream , 67returning non-zero if it is set. 68The end-of-file indicator can only be cleared by the function 69.Fn clearerr . 70.Pp 71The function 72.Fn ferror 73tests the error indicator for the stream pointed to by 74.Fa stream , 75returning non-zero if it is set. 76The error indicator can only be reset by the 77.Fn clearerr 78function. 79.Pp 80The function 81.Fn fileno 82examines the argument 83.Fa stream 84and returns its integer file descriptor. 85.Sh ERRORS 86These functions should not fail and do not set the external 87variable 88.Va errno . 89.Sh SEE ALSO 90.Xr open 2 , 91.Xr stdio 3 92.Sh STANDARDS 93The functions 94.Fn clearerr , 95.Fn feof , 96and 97.Fn ferror 98conform to 99.St -ansiC . 100The function 101.Fn fileno 102conforms to 103.St -p1003.1-90 . 104