mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-22 11:17:19 +00:00
137 lines
3.9 KiB
Groff
137 lines
3.9 KiB
Groff
.\" Copyright (c) 1990, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to Berkeley by
|
|
.\" Chris Torek and the American National Standards Committee X3,
|
|
.\" on Information Processing Systems.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)ferror.3 8.2 (Berkeley) 4/19/94
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd January 10, 2003
|
|
.Dt FERROR 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm clearerr ,
|
|
.Nm clearerr_unlocked ,
|
|
.Nm feof ,
|
|
.Nm feof_unlocked ,
|
|
.Nm ferror ,
|
|
.Nm ferror_unlocked ,
|
|
.Nm fileno ,
|
|
.Nm fileno_unlocked
|
|
.Nd check and reset stream status
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In stdio.h
|
|
.Ft void
|
|
.Fn clearerr "FILE *stream"
|
|
.Ft void
|
|
.Fn clearerr_unlocked "FILE *stream"
|
|
.Ft int
|
|
.Fn feof "FILE *stream"
|
|
.Ft int
|
|
.Fn feof_unlocked "FILE *stream"
|
|
.Ft int
|
|
.Fn ferror "FILE *stream"
|
|
.Ft int
|
|
.Fn ferror_unlocked "FILE *stream"
|
|
.Ft int
|
|
.Fn fileno "FILE *stream"
|
|
.Ft int
|
|
.Fn fileno_unlocked "FILE *stream"
|
|
.Sh DESCRIPTION
|
|
The function
|
|
.Fn clearerr
|
|
clears the end-of-file and error indicators for the stream pointed
|
|
to by
|
|
.Fa stream .
|
|
.Pp
|
|
The function
|
|
.Fn feof
|
|
tests the end-of-file indicator for the stream pointed to by
|
|
.Fa stream ,
|
|
returning non-zero if it is set.
|
|
The end-of-file indicator can only be cleared by the function
|
|
.Fn clearerr .
|
|
.Pp
|
|
The function
|
|
.Fn ferror
|
|
tests the error indicator for the stream pointed to by
|
|
.Fa stream ,
|
|
returning non-zero if it is set.
|
|
The error indicator can only be reset by the
|
|
.Fn clearerr
|
|
function.
|
|
.Pp
|
|
The function
|
|
.Fn fileno
|
|
examines the argument
|
|
.Fa stream
|
|
and returns its integer descriptor.
|
|
.Pp
|
|
The
|
|
.Fn clearerr_unlocked ,
|
|
.Fn feof_unlocked ,
|
|
.Fn ferror_unlocked ,
|
|
and
|
|
.Fn fileno_unlocked
|
|
functions are equivalent to
|
|
.Fn clearerr ,
|
|
.Fn feof ,
|
|
.Fn ferror ,
|
|
and
|
|
.Fn fileno
|
|
respectively, except that the caller is responsible for locking the stream
|
|
with
|
|
.Xr flockfile 3
|
|
before calling them.
|
|
These functions may be used to avoid the overhead of locking the stream
|
|
and to prevent races when multiple threads are operating on the same stream.
|
|
.Sh ERRORS
|
|
These functions should not fail and do not set the external
|
|
variable
|
|
.Va errno .
|
|
.Sh SEE ALSO
|
|
.Xr open 2 ,
|
|
.Xr fdopen 3 ,
|
|
.Xr flockfile 3 ,
|
|
.Xr stdio 3
|
|
.Sh STANDARDS
|
|
The functions
|
|
.Fn clearerr ,
|
|
.Fn feof ,
|
|
and
|
|
.Fn ferror
|
|
conform to
|
|
.St -isoC .
|