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.Dd $Mdocdate: July 17 2013 $
.Dt FERROR 3
.Os
.Sh NAME
.Nm clearerr ,
.Nm feof ,
.Nm ferror ,
.Nm fileno
.Nd check and reset stream status
.Sh SYNOPSIS
.In stdio.h
.Ft void
.Fn clearerr "FILE *stream"
.Ft int
.Fn feof "FILE *stream"
.Ft int
.Fn ferror "FILE *stream"
.Ft int
.Fn fileno "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.
.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 file descriptor.
.Sh ERRORS
These functions should not fail and do not set the external
variable
.Va errno .
.Sh SEE ALSO
.Xr open 2 ,
.Xr stdio 3
.Sh STANDARDS
The functions
.Fn clearerr ,
.Fn feof ,
and
.Fn ferror
conform to
.St -ansiC .
The function
.Fn fileno
conforms to
.St -p1003.1-90 .
.Sh HISTORY
The functions
.Fn clearerr ,
.Fn feof ,
.Fn ferror ,
and
.Fn fileno
first appeared in
.At v7 .