.\" $OpenBSD: isfdtype.3,v 1.9 2014/01/21 03:15:45 schwarze Exp $
.\"
.\" Copyright (c) 2002 Todd C. Miller <Todd.Miller@courtesan.com>
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.\"
.Dd $Mdocdate: January 21 2014 $
.Dt ISFDTYPE 3
.Os
.Sh NAME
.Nm isfdtype
.Nd determine whether a file descriptor is of a specific type
.Sh SYNOPSIS
.In sys/stat.h
.Ft int
.Fn isfdtype "int fd" "int fdtype"
.Sh DESCRIPTION
The
.Fn isfdtype
function checks whether or not the file descriptor
.Fa fd
is of type
.Fa fdtype .
.Pp
A list of possible file types may be found in
.Xr stat 2
and the
.In sys/stat.h
include file.
.Sh RETURN VALUES
The
.Fn isfdtype
function returns 1 if
.Fa fd
is of type
.Fa fdtype
and 0 if it is not.
If
.Fn isfdtype
fails, a value of \-1 is returned and the global variable
.Va errno
is set to indicate the error.
.Sh ERRORS
The following error codes may be set in
.Va errno :
.Bl -tag -width Er
.It Bq Er EBADF
.Fa fd
is not a valid open file descriptor.
.It Bq Er EIO
An I/O error occurred while reading from or writing to the file system.
.El
.Sh SEE ALSO
.Xr stat 2
.Sh HISTORY
The
.Fn isfdtype
function first appeared in
.Ox 3.3 .