.\"   $OpenBSD: identd.8,v 1.11 2013/07/17 15:38:47 okan Exp $
.\"
.\" Copyright (c) 2013 David Gwynne <dlg@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
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.Dd $Mdocdate: July 17 2013 $
.Dt IDENTD 8
.Os
.Sh NAME
.Nm identd
.Nd Identification Protocol daemon
.Sh SYNOPSIS
.Nm
.Op Fl 46deHhNn
.Op Fl l Ar address
.Op Fl t Ar timeout
.Sh DESCRIPTION
.Nm
is a server which implements the Identification Protocol as specified in
RFC 1413.
.Pp
.Nm
operates by looking up specific TCP/IP connections and returning
the name of the user running the process responsible for the connection.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl 4
Forces
.Nm
to use IPv4 addresses only.
.It Fl 6
Forces
.Nm
to use IPv6 addresses only.
.It Fl d
Do not daemonize.
If this option is specified,
.Nm
will run in the foreground and log to stderr.
.It Fl e
Always return
.Dq UNKNOWN-ERROR
instead of the
.Dq NO-USER
or
.Dq INVALID-PORT
errors.
.It Fl H
Hide information about existing and non-existent users.
This flag implies
.Fl h .
.It Fl h
Hide the actual information about the user by providing an opaque
token instead.
This token is entered into the local system logs
so that the administrator can later discover who the real user was.
.It Fl l Ar address
Listen on the specified address.
By default
.Nm
listens on wildcard addresses.
.It Fl N
When replying with a user name or ID, first
check for a file
.Pa .noident
in the user's home directory.
If this file is accessible, return
.Dq HIDDEN-USER
instead of the normal USERID response.
.It Fl n
Always return UID numbers instead of usernames.
.It Fl t Ar timeout
Specifies the idle timeout for client connections,
in seconds.
The default timeout is 120 seconds.
.El
.\" .Sh SEE ALSO
.Sh STANDARDS
.Rs
.%A M. St. Johns
.%D February 1993
.%R RFC 1413
.%T Identification Protocol
.Re
.Sh HISTORY
The
.Nm
command was originally a process run via
.Xr inetd 8 .
It was rewritten for
.Ox 5.4
as a persistent non-blocking daemon.