.\" $OpenBSD: isfdtype.3,v 1.7 2013/06/05 03:39:22 tedu Exp $
.\"
.\" Copyright (c) 2002 Todd C. Miller <Todd.Miller@courtesan.com>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.\" Sponsored in part by the Defense Advanced Research Projects
.\" Agency (DARPA) and Air Force Research Laboratory, Air Force
.\" Materiel Command, USAF, under agreement number F39502-99-1-0512.
.\"
.Dd $Mdocdate: June 5 2013 $
.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
.Aq Pa 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 .