1361 lines
30 KiB
Groff
1361 lines
30 KiB
Groff
.\" Copyright (c) 1983, 1990, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. All advertising materials mentioning features or use of this software
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.\" must display the following acknowledgement:
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.\" This product includes software developed by the University of
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.\" California, Berkeley and its contributors.
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.\" 4. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)telnet.1 8.5 (Berkeley) 3/1/94
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.\"
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.Dd March 1, 1994
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.Dt TELNET 1
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.Os BSD 4.2
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.Sh NAME
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.Nm telnet
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.Nd user interface to the
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.Tn TELNET
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protocol
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.Sh SYNOPSIS
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.Nm telnet
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.Op Fl 8EFKLacdfrx
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.Op Fl S Ar tos
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.Op Fl X Ar authtype
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.Op Fl e Ar escapechar
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.Op Fl k Ar realm
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.Op Fl l Ar user
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.Op Fl n Ar tracefile
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.Oo
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.Ar host
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.Op port
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.Oc
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.Sh DESCRIPTION
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The
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.Nm telnet
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command
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is used to communicate with another host using the
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.Tn TELNET
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protocol.
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If
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.Nm telnet
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is invoked without the
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.Ar host
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argument, it enters command mode,
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indicated by its prompt
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.Pq Nm telnet\&> .
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In this mode, it accepts and executes the commands listed below.
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If it is invoked with arguments, it performs an
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.Ic open
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command with those arguments.
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.Pp
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Options:
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.Bl -tag -width indent
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.It Fl 8
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Specifies an 8-bit data path. This causes an attempt to
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negotiate the
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.Dv TELNET BINARY
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option on both input and output.
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.It Fl E
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Stops any character from being recognized as an escape character.
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.It Fl F
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If Kerberos V5 authentication is being used, the
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.Fl F
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option allows the local credentials to be forwarded
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to the remote system, including any credentials that
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have already been forwarded into the local environment.
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.It Fl K
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Specifies no automatic login to the remote system.
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.It Fl L
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Specifies an 8-bit data path on output. This causes the
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BINARY option to be negotiated on output.
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.It Fl S Ar tos
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Sets the IP type-of-service (TOS) option for the telnet
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connection to the value
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.Ar tos,
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which can be a numeric TOS value
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or, on systems that support it, a symbolic
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TOS name found in the /etc/iptos file.
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.It Fl X Ar atype
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Disables the
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.Ar atype
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type of authentication.
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.It Fl a
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Attempt automatic login.
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Currently, this sends the user name via the
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.Ev USER
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variable
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of the
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.Ev ENVIRON
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option if supported by the remote system.
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The name used is that of the current user as returned by
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.Xr getlogin 2
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if it agrees with the current user ID,
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otherwise it is the name associated with the user ID.
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.It Fl c
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Disables the reading of the user's
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.Pa \&.telnetrc
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file. (See the
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.Ic toggle skiprc
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command on this man page.)
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.It Fl d
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Sets the initial value of the
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.Ic debug
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toggle to
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.Dv TRUE
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.It Fl e Ar escape char
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Sets the initial
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.Nm
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.Nm telnet
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escape character to
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.Ar escape char.
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If
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.Ar escape char
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is omitted, then
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there will be no escape character.
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.It Fl f
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If Kerberos V5 authentication is being used, the
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.Fl f
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option allows the local credentials to be forwarded to the remote system.
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.It Fl k Ar realm
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If Kerberos authentication is being used, the
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.Fl k
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option requests that telnet obtain tickets for the remote host in
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realm realm instead of the remote host's realm, as determined
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by
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.Xr krb_realmofhost 3 .
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.It Fl l Ar user
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When connecting to the remote system, if the remote system
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understands the
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.Ev ENVIRON
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option, then
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.Ar user
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will be sent to the remote system as the value for the variable USER.
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This option implies the
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.Fl a
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option.
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This option may also be used with the
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.Ic open
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command.
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.It Fl n Ar tracefile
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Opens
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.Ar tracefile
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for recording trace information.
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See the
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.Ic set tracefile
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command below.
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.It Fl r
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Specifies a user interface similar to
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.Xr rlogin 1 .
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In this
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mode, the escape character is set to the tilde (~) character,
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unless modified by the -e option.
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.It Fl x
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Turns on encryption of the data stream if possible. This
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option is not available outside of the United States and
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Canada.
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.It Ar host
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Indicates the official name, an alias, or the Internet address
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of a remote host.
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.It Ar port
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Indicates a port number (address of an application). If a number is
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not specified, the default
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.Nm telnet
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port is used.
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.El
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.Pp
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When in rlogin mode, a line of the form ~. disconnects from the
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remote host; ~ is the telnet escape character.
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Similarly, the line ~^Z suspends the telnet session.
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The line ~^] escapes to the normal telnet escape prompt.
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.Pp
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Once a connection has been opened,
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.Nm telnet
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will attempt to enable the
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.Dv TELNET LINEMODE
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option.
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If this fails, then
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.Nm telnet
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will revert to one of two input modes:
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either \*(Lqcharacter at a time\*(Rq
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or \*(Lqold line by line\*(Rq
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depending on what the remote system supports.
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.Pp
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When
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.Dv LINEMODE
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is enabled, character processing is done on the
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local system, under the control of the remote system. When input
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editing or character echoing is to be disabled, the remote system
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will relay that information. The remote system will also relay
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changes to any special characters that happen on the remote
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system, so that they can take effect on the local system.
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.Pp
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In \*(Lqcharacter at a time\*(Rq mode, most
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text typed is immediately sent to the remote host for processing.
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.Pp
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In \*(Lqold line by line\*(Rq mode, all text is echoed locally,
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and (normally) only completed lines are sent to the remote host.
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The \*(Lqlocal echo character\*(Rq (initially \*(Lq^E\*(Rq) may be used
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to turn off and on the local echo
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(this would mostly be used to enter passwords
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without the password being echoed).
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.Pp
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If the
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.Dv LINEMODE
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option is enabled, or if the
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.Ic localchars
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toggle is
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.Dv TRUE
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(the default for \*(Lqold line by line\*(Lq; see below),
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the user's
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.Ic quit ,
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.Ic intr ,
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and
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.Ic flush
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characters are trapped locally, and sent as
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.Tn TELNET
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protocol sequences to the remote side.
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If
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.Dv LINEMODE
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has ever been enabled, then the user's
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.Ic susp
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and
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.Ic eof
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are also sent as
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.Tn TELNET
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protocol sequences,
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and
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.Ic quit
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is sent as a
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.Dv TELNET ABORT
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instead of
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.Dv BREAK
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There are options (see
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.Ic toggle
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.Ic autoflush
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and
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.Ic toggle
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.Ic autosynch
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below)
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|
which cause this action to flush subsequent output to the terminal
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(until the remote host acknowledges the
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.Tn TELNET
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sequence) and flush previous terminal input
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(in the case of
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.Ic quit
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and
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.Ic intr ) .
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.Pp
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|
While connected to a remote host,
|
|
.Nm telnet
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|
command mode may be entered by typing the
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.Nm telnet
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\*(Lqescape character\*(Rq (initially \*(Lq^]\*(Rq).
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When in command mode, the normal terminal editing conventions are available.
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.Pp
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The following
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.Nm telnet
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commands are available.
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Only enough of each command to uniquely identify it need be typed
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(this is also true for arguments to the
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.Ic mode ,
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.Ic set ,
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.Ic toggle ,
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.Ic unset ,
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.Ic slc ,
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|
.Ic environ ,
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and
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.Ic display
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commands).
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|
.Pp
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.Bl -tag -width "mode type"
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|
.It Ic auth Ar argument ...
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|
The auth command manipulates the information sent through the
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.Dv TELNET AUTHENTICATE
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option. Valid arguments for the
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auth command are as follows:
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.Bl -tag -width "disable type"
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.It Ic disable Ar type
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Disables the specified type of authentication. To
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obtain a list of available types, use the
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.Ic auth disable \&?
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command.
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|
.It Ic enable Ar type
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|
Enables the specified type of authentication. To
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obtain a list of available types, use the
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|
.Ic auth enable \&?
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command.
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|
.It Ic status
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|
Lists the current status of the various types of
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authentication.
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.El
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.It Ic close
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|
Close a
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.Tn TELNET
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session and return to command mode.
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.It Ic display Ar argument ...
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Displays all, or some, of the
|
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.Ic set
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and
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.Ic toggle
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values (see below).
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.It Ic encrypt Ar argument ...
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|
The encrypt command manipulates the information sent through the
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.Dv TELNET ENCRYPT
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option.
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|
.Pp
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|
Note: Because of export controls, the
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.Dv TELNET ENCRYPT
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option is not supported outside of the United States and Canada.
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.Pp
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Valid arguments for the encrypt command are as follows:
|
|
.Bl -tag -width Ar
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.It Ic disable Ar type Ic [input|output]
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|
Disables the specified type of encryption. If you
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omit the input and output, both input and output
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are disabled. To obtain a list of available
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types, use the
|
|
.Ic encrypt disable \&?
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|
command.
|
|
.It Ic enable Ar type Ic [input|output]
|
|
Enables the specified type of encryption. If you
|
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omit input and output, both input and output are
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|
enabled. To obtain a list of available types, use the
|
|
.Ic encrypt enable \&?
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command.
|
|
.It Ic input
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This is the same as the
|
|
.Ic encrypt start input
|
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command.
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|
.It Ic -input
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This is the same as the
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|
.Ic encrypt stop input
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command.
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|
.It Ic output
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|
This is the same as the
|
|
.Ic encrypt start output
|
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command.
|
|
.It Ic -output
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This is the same as the
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|
.Ic encrypt stop output
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command.
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.It Ic start Ic [input|output]
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Attempts to start encryption. If you omit
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.Ic input
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and
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.Ic output,
|
|
both input and output are enabled. To
|
|
obtain a list of available types, use the
|
|
.Ic encrypt enable \&?
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|
command.
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|
.It Ic status
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|
Lists the current status of encryption.
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|
.It Ic stop Ic [input|output]
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|
Stops encryption. If you omit input and output,
|
|
encryption is on both input and output.
|
|
.It Ic type Ar type
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Sets the default type of encryption to be used
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with later
|
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.Ic encrypt start
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or
|
|
.Ic encrypt stop
|
|
commands.
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.El
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.It Ic environ Ar arguments...
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|
The
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.Ic environ
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command is used to manipulate the
|
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the variables that my be sent through the
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.Dv TELNET ENVIRON
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option.
|
|
The initial set of variables is taken from the users
|
|
environment, with only the
|
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.Ev DISPLAY
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|
and
|
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.Ev PRINTER
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|
variables being exported by default.
|
|
The
|
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.Ev USER
|
|
variable is also exported if the
|
|
.Fl a
|
|
or
|
|
.Fl l
|
|
options are used.
|
|
.br
|
|
Valid arguments for the
|
|
.Ic environ
|
|
command are:
|
|
.Bl -tag -width Fl
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|
.It Ic define Ar variable value
|
|
Define the variable
|
|
.Ar variable
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|
to have a value of
|
|
.Ar value.
|
|
Any variables defined by this command are automatically exported.
|
|
The
|
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.Ar value
|
|
may be enclosed in single or double quotes so
|
|
that tabs and spaces may be included.
|
|
.It Ic undefine Ar variable
|
|
Remove
|
|
.Ar variable
|
|
from the list of environment variables.
|
|
.It Ic export Ar variable
|
|
Mark the variable
|
|
.Ar variable
|
|
to be exported to the remote side.
|
|
.It Ic unexport Ar variable
|
|
Mark the variable
|
|
.Ar variable
|
|
to not be exported unless
|
|
explicitly asked for by the remote side.
|
|
.It Ic list
|
|
List the current set of environment variables.
|
|
Those marked with a
|
|
.Cm *
|
|
will be sent automatically,
|
|
other variables will only be sent if explicitly requested.
|
|
.It Ic \&?
|
|
Prints out help information for the
|
|
.Ic environ
|
|
command.
|
|
.El
|
|
.It Ic logout
|
|
Sends the
|
|
.Dv TELNET LOGOUT
|
|
option to the remote side.
|
|
This command is similar to a
|
|
.Ic close
|
|
command; however, if the remote side does not support the
|
|
.Dv LOGOUT
|
|
option, nothing happens.
|
|
If, however, the remote side does support the
|
|
.Dv LOGOUT
|
|
option, this command should cause the remote side to close the
|
|
.Tn TELNET
|
|
connection.
|
|
If the remote side also supports the concept of
|
|
suspending a user's session for later reattachment,
|
|
the logout argument indicates that you
|
|
should terminate the session immediately.
|
|
.It Ic mode Ar type
|
|
.Ar Type
|
|
is one of several options, depending on the state of the
|
|
.Tn TELNET
|
|
session.
|
|
The remote host is asked for permission to go into the requested mode.
|
|
If the remote host is capable of entering that mode, the requested
|
|
mode will be entered.
|
|
.Bl -tag -width Ar
|
|
.It Ic character
|
|
Disable the
|
|
.Dv TELNET LINEMODE
|
|
option, or, if the remote side does not understand the
|
|
.Dv LINEMODE
|
|
option, then enter \*(Lqcharacter at a time\*(Lq mode.
|
|
.It Ic line
|
|
Enable the
|
|
.Dv TELNET LINEMODE
|
|
option, or, if the remote side does not understand the
|
|
.Dv LINEMODE
|
|
option, then attempt to enter \*(Lqold-line-by-line\*(Lq mode.
|
|
.It Ic isig Pq Ic \-isig
|
|
Attempt to enable (disable) the
|
|
.Dv TRAPSIG
|
|
mode of the
|
|
.Dv LINEMODE
|
|
option.
|
|
This requires that the
|
|
.Dv LINEMODE
|
|
option be enabled.
|
|
.It Ic edit Pq Ic \-edit
|
|
Attempt to enable (disable) the
|
|
.Dv EDIT
|
|
mode of the
|
|
.Dv LINEMODE
|
|
option.
|
|
This requires that the
|
|
.Dv LINEMODE
|
|
option be enabled.
|
|
.It Ic softtabs Pq Ic \-softtabs
|
|
Attempt to enable (disable) the
|
|
.Dv SOFT_TAB
|
|
mode of the
|
|
.Dv LINEMODE
|
|
option.
|
|
This requires that the
|
|
.Dv LINEMODE
|
|
option be enabled.
|
|
.It Ic litecho Pq Ic \-litecho
|
|
Attempt to enable (disable) the
|
|
.Dv LIT_ECHO
|
|
mode of the
|
|
.Dv LINEMODE
|
|
option.
|
|
This requires that the
|
|
.Dv LINEMODE
|
|
option be enabled.
|
|
.It Ic \&?
|
|
Prints out help information for the
|
|
.Ic mode
|
|
command.
|
|
.El
|
|
.It Xo
|
|
.Ic open Ar host
|
|
.Oo Op Fl l
|
|
.Ar user
|
|
.Oc Ns Oo Fl
|
|
.Ar port Oc
|
|
.Xc
|
|
Open a connection to the named host.
|
|
If no port number
|
|
is specified,
|
|
.Nm telnet
|
|
will attempt to contact a
|
|
.Tn TELNET
|
|
server at the default port.
|
|
The host specification may be either a host name (see
|
|
.Xr hosts 5 )
|
|
or an Internet address specified in the \*(Lqdot notation\*(Rq (see
|
|
.Xr inet 3 ) .
|
|
The
|
|
.Op Fl l
|
|
option may be used to specify the user name
|
|
to be passed to the remote system via the
|
|
.Ev ENVIRON
|
|
option.
|
|
When connecting to a non-standard port,
|
|
.Nm telnet
|
|
omits any automatic initiation of
|
|
.Tn TELNET
|
|
options. When the port number is preceded by a minus sign,
|
|
the initial option negotiation is done.
|
|
After establishing a connection, the file
|
|
.Pa \&.telnetrc
|
|
in the
|
|
users home directory is opened. Lines beginning with a # are
|
|
comment lines. Blank lines are ignored. Lines that begin
|
|
without white space are the start of a machine entry. The
|
|
first thing on the line is the name of the machine that is
|
|
being connected to. The rest of the line, and successive
|
|
lines that begin with white space are assumed to be
|
|
.Nm telnet
|
|
commands and are processed as if they had been typed
|
|
in manually to the
|
|
.Nm telnet
|
|
command prompt.
|
|
.It Ic quit
|
|
Close any open
|
|
.Tn TELNET
|
|
session and exit
|
|
.Nm telnet .
|
|
An end of file (in command mode) will also close a session and exit.
|
|
.It Ic send Ar arguments
|
|
Sends one or more special character sequences to the remote host.
|
|
The following are the arguments which may be specified
|
|
(more than one argument may be specified at a time):
|
|
.Pp
|
|
.Bl -tag -width escape
|
|
.It Ic abort
|
|
Sends the
|
|
.Dv TELNET ABORT
|
|
(Abort
|
|
processes)
|
|
sequence.
|
|
.It Ic ao
|
|
Sends the
|
|
.Dv TELNET AO
|
|
(Abort Output) sequence, which should cause the remote system to flush
|
|
all output
|
|
.Em from
|
|
the remote system
|
|
.Em to
|
|
the user's terminal.
|
|
.It Ic ayt
|
|
Sends the
|
|
.Dv TELNET AYT
|
|
(Are You There)
|
|
sequence, to which the remote system may or may not choose to respond.
|
|
.It Ic brk
|
|
Sends the
|
|
.Dv TELNET BRK
|
|
(Break) sequence, which may have significance to the remote
|
|
system.
|
|
.It Ic ec
|
|
Sends the
|
|
.Dv TELNET EC
|
|
(Erase Character)
|
|
sequence, which should cause the remote system to erase the last character
|
|
entered.
|
|
.It Ic el
|
|
Sends the
|
|
.Dv TELNET EL
|
|
(Erase Line)
|
|
sequence, which should cause the remote system to erase the line currently
|
|
being entered.
|
|
.It Ic eof
|
|
Sends the
|
|
.Dv TELNET EOF
|
|
(End Of File)
|
|
sequence.
|
|
.It Ic eor
|
|
Sends the
|
|
.Dv TELNET EOR
|
|
(End of Record)
|
|
sequence.
|
|
.It Ic escape
|
|
Sends the current
|
|
.Nm telnet
|
|
escape character (initially \*(Lq^\*(Rq).
|
|
.It Ic ga
|
|
Sends the
|
|
.Dv TELNET GA
|
|
(Go Ahead)
|
|
sequence, which likely has no significance to the remote system.
|
|
.It Ic getstatus
|
|
If the remote side supports the
|
|
.Dv TELNET STATUS
|
|
command,
|
|
.Ic getstatus
|
|
will send the subnegotiation to request that the server send
|
|
its current option status.
|
|
.It Ic ip
|
|
Sends the
|
|
.Dv TELNET IP
|
|
(Interrupt Process) sequence, which should cause the remote
|
|
system to abort the currently running process.
|
|
.It Ic nop
|
|
Sends the
|
|
.Dv TELNET NOP
|
|
(No OPeration)
|
|
sequence.
|
|
.It Ic susp
|
|
Sends the
|
|
.Dv TELNET SUSP
|
|
(SUSPend process)
|
|
sequence.
|
|
.It Ic synch
|
|
Sends the
|
|
.Dv TELNET SYNCH
|
|
sequence.
|
|
This sequence causes the remote system to discard all previously typed
|
|
(but not yet read) input.
|
|
This sequence is sent as
|
|
.Tn TCP
|
|
urgent
|
|
data (and may not work if the remote system is a
|
|
.Bx 4.2
|
|
system -- if
|
|
it doesn't work, a lower case \*(Lqr\*(Rq may be echoed on the terminal).
|
|
.It Ic do Ar cmd
|
|
.It Ic dont Ar cmd
|
|
.It Ic will Ar cmd
|
|
.It Ic wont Ar cmd
|
|
Sends the
|
|
.Dv TELNET DO
|
|
.Ar cmd
|
|
sequence.
|
|
.Ar Cmd
|
|
can be either a decimal number between 0 and 255,
|
|
or a symbolic name for a specific
|
|
.Dv TELNET
|
|
command.
|
|
.Ar Cmd
|
|
can also be either
|
|
.Ic help
|
|
or
|
|
.Ic \&?
|
|
to print out help information, including
|
|
a list of known symbolic names.
|
|
.It Ic \&?
|
|
Prints out help information for the
|
|
.Ic send
|
|
command.
|
|
.El
|
|
.It Ic set Ar argument value
|
|
.It Ic unset Ar argument value
|
|
The
|
|
.Ic set
|
|
command will set any one of a number of
|
|
.Nm telnet
|
|
variables to a specific value or to
|
|
.Dv TRUE .
|
|
The special value
|
|
.Ic off
|
|
turns off the function associated with
|
|
the variable, this is equivalent to using the
|
|
.Ic unset
|
|
command.
|
|
The
|
|
.Ic unset
|
|
command will disable or set to
|
|
.Dv FALSE
|
|
any of the specified functions.
|
|
The values of variables may be interrogated with the
|
|
.Ic display
|
|
command.
|
|
The variables which may be set or unset, but not toggled, are
|
|
listed here. In addition, any of the variables for the
|
|
.Ic toggle
|
|
command may be explicitly set or unset using
|
|
the
|
|
.Ic set
|
|
and
|
|
.Ic unset
|
|
commands.
|
|
.Bl -tag -width escape
|
|
.It Ic ayt
|
|
If
|
|
.Tn TELNET
|
|
is in localchars mode, or
|
|
.Dv LINEMODE
|
|
is enabled, and the status character is typed, a
|
|
.Dv TELNET AYT
|
|
sequence (see
|
|
.Ic send ayt
|
|
preceding) is sent to the
|
|
remote host. The initial value for the "Are You There"
|
|
character is the terminal's status character.
|
|
.It Ic echo
|
|
This is the value (initially \*(Lq^E\*(Rq) which, when in
|
|
\*(Lqline by line\*(Rq mode, toggles between doing local echoing
|
|
of entered characters (for normal processing), and suppressing
|
|
echoing of entered characters (for entering, say, a password).
|
|
.It Ic eof
|
|
If
|
|
.Nm telnet
|
|
is operating in
|
|
.Dv LINEMODE
|
|
or \*(Lqold line by line\*(Rq mode, entering this character
|
|
as the first character on a line will cause this character to be
|
|
sent to the remote system.
|
|
The initial value of the eof character is taken to be the terminal's
|
|
.Ic eof
|
|
character.
|
|
.It Ic erase
|
|
If
|
|
.Nm telnet
|
|
is in
|
|
.Ic localchars
|
|
mode (see
|
|
.Ic toggle
|
|
.Ic localchars
|
|
below),
|
|
.Sy and
|
|
if
|
|
.Nm telnet
|
|
is operating in \*(Lqcharacter at a time\*(Rq mode, then when this
|
|
character is typed, a
|
|
.Dv TELNET EC
|
|
sequence (see
|
|
.Ic send
|
|
.Ic ec
|
|
above)
|
|
is sent to the remote system.
|
|
The initial value for the erase character is taken to be
|
|
the terminal's
|
|
.Ic erase
|
|
character.
|
|
.It Ic escape
|
|
This is the
|
|
.Nm telnet
|
|
escape character (initially \*(Lq^[\*(Rq) which causes entry
|
|
into
|
|
.Nm telnet
|
|
command mode (when connected to a remote system).
|
|
.It Ic flushoutput
|
|
If
|
|
.Nm telnet
|
|
is in
|
|
.Ic localchars
|
|
mode (see
|
|
.Ic toggle
|
|
.Ic localchars
|
|
below)
|
|
and the
|
|
.Ic flushoutput
|
|
character is typed, a
|
|
.Dv TELNET AO
|
|
sequence (see
|
|
.Ic send
|
|
.Ic ao
|
|
above)
|
|
is sent to the remote host.
|
|
The initial value for the flush character is taken to be
|
|
the terminal's
|
|
.Ic flush
|
|
character.
|
|
.It Ic forw1
|
|
.It Ic forw2
|
|
If
|
|
.Tn TELNET
|
|
is operating in
|
|
.Dv LINEMODE ,
|
|
these are the
|
|
characters that, when typed, cause partial lines to be
|
|
forwarded to the remote system. The initial value for
|
|
the forwarding characters are taken from the terminal's
|
|
eol and eol2 characters.
|
|
.It Ic interrupt
|
|
If
|
|
.Nm telnet
|
|
is in
|
|
.Ic localchars
|
|
mode (see
|
|
.Ic toggle
|
|
.Ic localchars
|
|
below)
|
|
and the
|
|
.Ic interrupt
|
|
character is typed, a
|
|
.Dv TELNET IP
|
|
sequence (see
|
|
.Ic send
|
|
.Ic ip
|
|
above)
|
|
is sent to the remote host.
|
|
The initial value for the interrupt character is taken to be
|
|
the terminal's
|
|
.Ic intr
|
|
character.
|
|
.It Ic kill
|
|
If
|
|
.Nm telnet
|
|
is in
|
|
.Ic localchars
|
|
mode (see
|
|
.Ic toggle
|
|
.Ic localchars
|
|
below),
|
|
.Ic and
|
|
if
|
|
.Nm telnet
|
|
is operating in \*(Lqcharacter at a time\*(Rq mode, then when this
|
|
character is typed, a
|
|
.Dv TELNET EL
|
|
sequence (see
|
|
.Ic send
|
|
.Ic el
|
|
above)
|
|
is sent to the remote system.
|
|
The initial value for the kill character is taken to be
|
|
the terminal's
|
|
.Ic kill
|
|
character.
|
|
.It Ic lnext
|
|
If
|
|
.Nm telnet
|
|
is operating in
|
|
.Dv LINEMODE
|
|
or \*(Lqold line by line\*(Lq mode, then this character is taken to
|
|
be the terminal's
|
|
.Ic lnext
|
|
character.
|
|
The initial value for the lnext character is taken to be
|
|
the terminal's
|
|
.Ic lnext
|
|
character.
|
|
.It Ic quit
|
|
If
|
|
.Nm telnet
|
|
is in
|
|
.Ic localchars
|
|
mode (see
|
|
.Ic toggle
|
|
.Ic localchars
|
|
below)
|
|
and the
|
|
.Ic quit
|
|
character is typed, a
|
|
.Dv TELNET BRK
|
|
sequence (see
|
|
.Ic send
|
|
.Ic brk
|
|
above)
|
|
is sent to the remote host.
|
|
The initial value for the quit character is taken to be
|
|
the terminal's
|
|
.Ic quit
|
|
character.
|
|
.It Ic reprint
|
|
If
|
|
.Nm telnet
|
|
is operating in
|
|
.Dv LINEMODE
|
|
or \*(Lqold line by line\*(Lq mode, then this character is taken to
|
|
be the terminal's
|
|
.Ic reprint
|
|
character.
|
|
The initial value for the reprint character is taken to be
|
|
the terminal's
|
|
.Ic reprint
|
|
character.
|
|
.It Ic rlogin
|
|
This is the rlogin escape character.
|
|
If set, the normal
|
|
.Tn TELNET
|
|
escape character is ignored unless it is
|
|
preceded by this character at the beginning of a line.
|
|
This character, at the beginning of a line followed by
|
|
a "." closes the connection; when followed by a ^Z it
|
|
suspends the telnet command. The initial state is to
|
|
disable the rlogin escape character.
|
|
.It Ic start
|
|
If the
|
|
.Dv TELNET TOGGLE-FLOW-CONTROL
|
|
option has been enabled,
|
|
then this character is taken to
|
|
be the terminal's
|
|
.Ic start
|
|
character.
|
|
The initial value for the kill character is taken to be
|
|
the terminal's
|
|
.Ic start
|
|
character.
|
|
.It Ic stop
|
|
If the
|
|
.Dv TELNET TOGGLE-FLOW-CONTROL
|
|
option has been enabled,
|
|
then this character is taken to
|
|
be the terminal's
|
|
.Ic stop
|
|
character.
|
|
The initial value for the kill character is taken to be
|
|
the terminal's
|
|
.Ic stop
|
|
character.
|
|
.It Ic susp
|
|
If
|
|
.Nm telnet
|
|
is in
|
|
.Ic localchars
|
|
mode, or
|
|
.Dv LINEMODE
|
|
is enabled, and the
|
|
.Ic suspend
|
|
character is typed, a
|
|
.Dv TELNET SUSP
|
|
sequence (see
|
|
.Ic send
|
|
.Ic susp
|
|
above)
|
|
is sent to the remote host.
|
|
The initial value for the suspend character is taken to be
|
|
the terminal's
|
|
.Ic suspend
|
|
character.
|
|
.It Ic tracefile
|
|
This is the file to which the output, caused by
|
|
.Ic netdata
|
|
or
|
|
.Ic option
|
|
tracing being
|
|
.Dv TRUE ,
|
|
will be written. If it is set to
|
|
.Dq Fl ,
|
|
then tracing information will be written to standard output (the default).
|
|
.It Ic worderase
|
|
If
|
|
.Nm telnet
|
|
is operating in
|
|
.Dv LINEMODE
|
|
or \*(Lqold line by line\*(Lq mode, then this character is taken to
|
|
be the terminal's
|
|
.Ic worderase
|
|
character.
|
|
The initial value for the worderase character is taken to be
|
|
the terminal's
|
|
.Ic worderase
|
|
character.
|
|
.It Ic \&?
|
|
Displays the legal
|
|
.Ic set
|
|
.Pq Ic unset
|
|
commands.
|
|
.El
|
|
.It Ic slc Ar state
|
|
The
|
|
.Ic slc
|
|
command (Set Local Characters) is used to set
|
|
or change the state of the the special
|
|
characters when the
|
|
.Dv TELNET LINEMODE
|
|
option has
|
|
been enabled. Special characters are characters that get
|
|
mapped to
|
|
.Tn TELNET
|
|
commands sequences (like
|
|
.Ic ip
|
|
or
|
|
.Ic quit )
|
|
or line editing characters (like
|
|
.Ic erase
|
|
and
|
|
.Ic kill ) .
|
|
By default, the local special characters are exported.
|
|
.Bl -tag -width Fl
|
|
.It Ic check
|
|
Verify the current settings for the current special characters.
|
|
The remote side is requested to send all the current special
|
|
character settings, and if there are any discrepancies with
|
|
the local side, the local side will switch to the remote value.
|
|
.It Ic export
|
|
Switch to the local defaults for the special characters. The
|
|
local default characters are those of the local terminal at
|
|
the time when
|
|
.Nm telnet
|
|
was started.
|
|
.It Ic import
|
|
Switch to the remote defaults for the special characters.
|
|
The remote default characters are those of the remote system
|
|
at the time when the
|
|
.Tn TELNET
|
|
connection was established.
|
|
.It Ic \&?
|
|
Prints out help information for the
|
|
.Ic slc
|
|
command.
|
|
.El
|
|
.It Ic status
|
|
Show the current status of
|
|
.Nm telnet .
|
|
This includes the peer one is connected to, as well
|
|
as the current mode.
|
|
.It Ic toggle Ar arguments ...
|
|
Toggle (between
|
|
.Dv TRUE
|
|
and
|
|
.Dv FALSE )
|
|
various flags that control how
|
|
.Nm telnet
|
|
responds to events.
|
|
These flags may be set explicitly to
|
|
.Dv TRUE
|
|
or
|
|
.Dv FALSE
|
|
using the
|
|
.Ic set
|
|
and
|
|
.Ic unset
|
|
commands listed above.
|
|
More than one argument may be specified.
|
|
The state of these flags may be interrogated with the
|
|
.Ic display
|
|
command.
|
|
Valid arguments are:
|
|
.Bl -tag -width Ar
|
|
.It Ic authdebug
|
|
Turns on debugging information for the authentication code.
|
|
.It Ic autoflush
|
|
If
|
|
.Ic autoflush
|
|
and
|
|
.Ic localchars
|
|
are both
|
|
.Dv TRUE ,
|
|
then when the
|
|
.Ic ao ,
|
|
or
|
|
.Ic quit
|
|
characters are recognized (and transformed into
|
|
.Tn TELNET
|
|
sequences; see
|
|
.Ic set
|
|
above for details),
|
|
.Nm telnet
|
|
refuses to display any data on the user's terminal
|
|
until the remote system acknowledges (via a
|
|
.Dv TELNET TIMING MARK
|
|
option)
|
|
that it has processed those
|
|
.Tn TELNET
|
|
sequences.
|
|
The initial value for this toggle is
|
|
.Dv TRUE
|
|
if the terminal user had not
|
|
done an "stty noflsh", otherwise
|
|
.Dv FALSE
|
|
(see
|
|
.Xr stty 1 ) .
|
|
.It Ic autodecrypt
|
|
When the
|
|
.Dv TELNET ENCRYPT
|
|
option is negotiated, by
|
|
default the actual encryption (decryption) of the data
|
|
stream does not start automatically. The autoencrypt
|
|
(autodecrypt) command states that encryption of the
|
|
output (input) stream should be enabled as soon as
|
|
possible.
|
|
.Pp
|
|
Note: Because of export controls, the
|
|
.Dv TELNET ENCRYPT
|
|
option is not supported outside the United States and Canada.
|
|
.It Ic autologin
|
|
If the remote side supports the
|
|
.Dv TELNET AUTHENTICATION
|
|
option
|
|
.Tn TELNET
|
|
attempts to use it to perform automatic authentication. If the
|
|
.Dv AUTHENTICATION
|
|
option is not supported, the user's login
|
|
name are propagated through the
|
|
.Dv TELNET ENVIRON
|
|
option.
|
|
This command is the same as specifying
|
|
.Ar a
|
|
option on the
|
|
.Ic open
|
|
command.
|
|
.It Ic autosynch
|
|
If
|
|
.Ic autosynch
|
|
and
|
|
.Ic localchars
|
|
are both
|
|
.Dv TRUE ,
|
|
then when either the
|
|
.Ic intr
|
|
or
|
|
.Ic quit
|
|
characters is typed (see
|
|
.Ic set
|
|
above for descriptions of the
|
|
.Ic intr
|
|
and
|
|
.Ic quit
|
|
characters), the resulting
|
|
.Tn TELNET
|
|
sequence sent is followed by the
|
|
.Dv TELNET SYNCH
|
|
sequence.
|
|
This procedure
|
|
.Ic should
|
|
cause the remote system to begin throwing away all previously
|
|
typed input until both of the
|
|
.Tn TELNET
|
|
sequences have been read and acted upon.
|
|
The initial value of this toggle is
|
|
.Dv FALSE .
|
|
.It Ic binary
|
|
Enable or disable the
|
|
.Dv TELNET BINARY
|
|
option on both input and output.
|
|
.It Ic inbinary
|
|
Enable or disable the
|
|
.Dv TELNET BINARY
|
|
option on input.
|
|
.It Ic outbinary
|
|
Enable or disable the
|
|
.Dv TELNET BINARY
|
|
option on output.
|
|
.It Ic crlf
|
|
If this is
|
|
.Dv TRUE ,
|
|
then carriage returns will be sent as
|
|
.Li <CR><LF> .
|
|
If this is
|
|
.Dv FALSE ,
|
|
then carriage returns will be send as
|
|
.Li <CR><NUL> .
|
|
The initial value for this toggle is
|
|
.Dv FALSE .
|
|
.It Ic crmod
|
|
Toggle carriage return mode.
|
|
When this mode is enabled, most carriage return characters received from
|
|
the remote host will be mapped into a carriage return followed by
|
|
a line feed.
|
|
This mode does not affect those characters typed by the user, only
|
|
those received from the remote host.
|
|
This mode is not very useful unless the remote host
|
|
only sends carriage return, but never line feed.
|
|
The initial value for this toggle is
|
|
.Dv FALSE .
|
|
.It Ic debug
|
|
Toggles socket level debugging (useful only to the
|
|
.Ic super user ) .
|
|
The initial value for this toggle is
|
|
.Dv FALSE .
|
|
.It Ic encdebug
|
|
Turns on debugging information for the encryption code.
|
|
.It Ic localchars
|
|
If this is
|
|
.Dv TRUE ,
|
|
then the
|
|
.Ic flush ,
|
|
.Ic interrupt ,
|
|
.Ic quit ,
|
|
.Ic erase ,
|
|
and
|
|
.Ic kill
|
|
characters (see
|
|
.Ic set
|
|
above) are recognized locally, and transformed into (hopefully) appropriate
|
|
.Tn TELNET
|
|
control sequences
|
|
(respectively
|
|
.Ic ao ,
|
|
.Ic ip ,
|
|
.Ic brk ,
|
|
.Ic ec ,
|
|
and
|
|
.Ic el ;
|
|
see
|
|
.Ic send
|
|
above).
|
|
The initial value for this toggle is
|
|
.Dv TRUE
|
|
in \*(Lqold line by line\*(Rq mode,
|
|
and
|
|
.Dv FALSE
|
|
in \*(Lqcharacter at a time\*(Rq mode.
|
|
When the
|
|
.Dv LINEMODE
|
|
option is enabled, the value of
|
|
.Ic localchars
|
|
is ignored, and assumed to always be
|
|
.Dv TRUE .
|
|
If
|
|
.Dv LINEMODE
|
|
has ever been enabled, then
|
|
.Ic quit
|
|
is sent as
|
|
.Ic abort ,
|
|
and
|
|
.Ic eof and
|
|
.B suspend
|
|
are sent as
|
|
.Ic eof and
|
|
.Ic susp ,
|
|
see
|
|
.Ic send
|
|
above).
|
|
.It Ic netdata
|
|
Toggles the display of all network data (in hexadecimal format).
|
|
The initial value for this toggle is
|
|
.Dv FALSE .
|
|
.It Ic options
|
|
Toggles the display of some internal
|
|
.Nm telnet
|
|
protocol processing (having to do with
|
|
.Tn TELNET
|
|
options).
|
|
The initial value for this toggle is
|
|
.Dv FALSE .
|
|
.It Ic prettydump
|
|
When the
|
|
.Ic netdata
|
|
toggle is enabled, if
|
|
.Ic prettydump
|
|
is enabled the output from the
|
|
.Ic netdata
|
|
command will be formatted in a more user readable format.
|
|
Spaces are put between each character in the output, and the
|
|
beginning of any
|
|
.Tn TELNET
|
|
escape sequence is preceded by a '*' to aid in locating them.
|
|
.It Ic skiprc
|
|
When the skiprc toggle is
|
|
.Dv TRUE ,
|
|
.Tn TELNET
|
|
skips the reading of the
|
|
.Pa \&.telnetrc
|
|
file in the users home
|
|
directory when connections are opened. The initial
|
|
value for this toggle is
|
|
.Dv FALSE.
|
|
.It Ic termdata
|
|
Toggles the display of all terminal data (in hexadecimal format).
|
|
The initial value for this toggle is
|
|
.Dv FALSE .
|
|
.It Ic verbose_encrypt
|
|
When the
|
|
.Ic verbose_encrypt
|
|
toggle is
|
|
.Dv TRUE ,
|
|
.Tn TELNET
|
|
prints out a message each time encryption is enabled or
|
|
disabled. The initial value for this toggle is
|
|
.Dv FALSE.
|
|
Note: Because of export controls, data encryption
|
|
is not supported outside of the United States and Canada.
|
|
.It Ic \&?
|
|
Displays the legal
|
|
.Ic toggle
|
|
commands.
|
|
.El
|
|
.It Ic z
|
|
Suspend
|
|
.Nm telnet .
|
|
This command only works when the user is using the
|
|
.Xr csh 1 .
|
|
.It Ic \&! Op Ar command
|
|
Execute a single command in a subshell on the local
|
|
system. If
|
|
.Ic command
|
|
is omitted, then an interactive
|
|
subshell is invoked.
|
|
.It Ic \&? Op Ar command
|
|
Get help. With no arguments,
|
|
.Nm telnet
|
|
prints a help summary.
|
|
If a command is specified,
|
|
.Nm telnet
|
|
will print the help information for just that command.
|
|
.El
|
|
.Sh ENVIRONMENT
|
|
.Nm Telnet
|
|
uses at least the
|
|
.Ev HOME ,
|
|
.Ev SHELL ,
|
|
.Ev DISPLAY ,
|
|
and
|
|
.Ev TERM
|
|
environment variables.
|
|
Other environment variables may be propagated
|
|
to the other side via the
|
|
.Dv TELNET ENVIRON
|
|
option.
|
|
.Sh FILES
|
|
.Bl -tag -width ~/.telnetrc -compact
|
|
.It Pa ~/.telnetrc
|
|
user customized telnet startup values
|
|
.El
|
|
.Sh HISTORY
|
|
The
|
|
.Nm Telnet
|
|
command appeared in
|
|
.Bx 4.2 .
|
|
.Sh NOTES
|
|
.Pp
|
|
On some remote systems, echo has to be turned off manually when in
|
|
\*(Lqold line by line\*(Rq mode.
|
|
.Pp
|
|
In \*(Lqold line by line\*(Rq mode or
|
|
.Dv LINEMODE
|
|
the terminal's
|
|
.Ic eof
|
|
character is only recognized (and sent to the remote system)
|
|
when it is the first character on a line.
|