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.\" 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 61to by 62.Fa stream . 63.Pp 64The function 65.Fn feof 66tests the end-of-file indicator for the stream pointed to by 67.Fa stream , 68returning non-zero if it is set. 69The end-of-file indicator can only be cleared by the function 70.Fn clearerr . 71.Pp 72The function 73.Fn ferror 74tests the error indicator for the stream pointed to by 75.Fa stream , 76returning non-zero if it is set. 77The error indicator can only be reset by the 78.Fn clearerr 79function. 80.Pp 81The function 82.Fn fileno 83examines the argument 84.Fa stream 85and returns its integer descriptor. 86.Sh ERRORS 87These functions should not fail and do not set the external 88variable 89.Va errno . 90.Sh SEE ALSO 91.Xr open 2 , 92.Xr stdio 3 93.Sh STANDARDS 94The functions 95.Fn clearerr , 96.Fn feof , 97and 98.Fn ferror 99conform to 100.St -ansiC . 101