1.\" $OpenBSD: isfdtype.3,v 1.10 2019/01/25 00:19:25 millert Exp $ 2.\" 3.\" Copyright (c) 2002 Todd C. Miller <millert@openbsd.org> 4.\" 5.\" Permission to use, copy, modify, and distribute this software for any 6.\" purpose with or without fee is hereby granted, provided that the above 7.\" copyright notice and this permission notice appear in all copies. 8.\" 9.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16.\" 17.\" Sponsored in part by the Defense Advanced Research Projects 18.\" Agency (DARPA) and Air Force Research Laboratory, Air Force 19.\" Materiel Command, USAF, under agreement number F39502-99-1-0512. 20.\" 21.Dd $Mdocdate: January 25 2019 $ 22.Dt ISFDTYPE 3 23.Os 24.Sh NAME 25.Nm isfdtype 26.Nd determine whether a file descriptor is of a specific type 27.Sh SYNOPSIS 28.In sys/stat.h 29.Ft int 30.Fn isfdtype "int fd" "int fdtype" 31.Sh DESCRIPTION 32The 33.Fn isfdtype 34function checks whether or not the file descriptor 35.Fa fd 36is of type 37.Fa fdtype . 38.Pp 39A list of possible file types may be found in 40.Xr stat 2 41and the 42.In sys/stat.h 43include file. 44.Sh RETURN VALUES 45The 46.Fn isfdtype 47function returns 1 if 48.Fa fd 49is of type 50.Fa fdtype 51and 0 if it is not. 52If 53.Fn isfdtype 54fails, a value of \-1 is returned and the global variable 55.Va errno 56is set to indicate the error. 57.Sh ERRORS 58The following error codes may be set in 59.Va errno : 60.Bl -tag -width Er 61.It Bq Er EBADF 62.Fa fd 63is not a valid open file descriptor. 64.It Bq Er EIO 65An I/O error occurred while reading from or writing to the file system. 66.El 67.Sh SEE ALSO 68.Xr stat 2 69.Sh HISTORY 70The 71.Fn isfdtype 72function first appeared in 73.Ox 3.3 . 74