.\" Copyright (c) 1983 The Regents of the University of California.
.\" Redistribution and use in source and binary forms are permitted
.\" provided that the above copyright notice and this paragraph are
.\" duplicated in all such forms and that any documentation,
.\" advertising materials, and other materials related to such
.\" distribution and use acknowledge that the software was developed
.\" by the University of California, Berkeley. The name of the
.\" University may not be used to endorse or promote products derived
.\" from this software without specific prior written permission.
.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
.\" WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
.\" @(#)telnet.1 6.6 (Berkeley) 9/21/88
.TH TELNET 1 "September 21, 1988"
telnet \- user interface to the \s-1TELNET\s0 protocol
is used to communicate with another host using the
is invoked without arguments, it enters command mode,
indicated by its prompt (\*(lqtelnet>\*(rq).
In this mode, it accepts and executes the commands listed below.
If it is invoked with arguments, it performs an
command (see below) with those arguments.
Once a connection has been opened,
The input mode entered will be either \*(lqcharacter at a time\*(rq
or \*(lqline by line\*(rq
depending on what the remote system supports.
In \*(lqcharacter at a time\*(rq mode, most
text typed is immediately sent to the remote host for processing.
In \*(lqline by line\*(rq mode, all text is echoed locally,
and (normally) only completed lines are sent to the remote host.
The \*(lqlocal echo character\*(rq (initially \*(lq^E\*(rq) may be used
to turn off and on the local echo
(this would mostly be used to enter passwords
without the password being echoed).
toggle is TRUE (the default in line mode; see below),
characters are trapped locally, and sent as
protocol sequences to the remote side.
which cause this action to flush subsequent output to the terminal
(until the remote host acknowledges the
sequence) and flush previous terminal input
While connected to a remote host,
command mode may be entered by typing the
\*(lqescape character\*(rq (initially \*(lq^]\*(rq).
When in command mode, the normal terminal editing conventions are available.
The following commands are available.
Only enough of each command to uniquely identify it need be typed
(this is also true for arguments to the
.B open \fIhost\fP \fR[\fP \fIport\fP \fR]\fP
Open a connection to the named host.
will attempt to contact a
server at the default port.
The host specification may be either a host name (see
or an Internet address specified in the \*(lqdot notation\*(rq (see
session and return to command mode.
An end of file (in command mode) will also close a session and exit.
This command only works when the user is using the
(for \*(lqline by line\*(rq mode)
(for \*(lqcharacter at a time\*(rq mode).
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
Show the current status of
This includes the peer one is connected to, as well
.B display \fR[\fP \fIargument...\fP \fR]\fP
Displays all, or some, of the
.B ? \fR[\fP \fIcommand\fP \fR]\fP
Get help. With no arguments,
If a command is specified,
will print the help information for just that command.
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):
escape character (initially \*(lq^]\*(rq).
This sequence causes the remote system to discard all previously typed
(but not yet read) input.
This sequence is sent as TCP urgent
data (and may not work if the remote system is a 4.2 BSD system -- if
it doesn't work, a lower case \*(lqr\*(rq may be echoed on the terminal).
(Break) sequence, which may have significance to the remote
(Interrupt Process) sequence, which should cause the remote
system to abort the currently running process.
(Abort Output) sequence, which should cause the remote system to flush
sequence, to which the remote system may or may not choose to respond.
sequence, which should cause the remote system to erase the last character
sequence, which should cause the remote system to erase the line currently
sequence, which likely has no significance to the remote system.
Prints out help information for the
.B set \fIargument value\fP
Set any one of a number of
variables to a specific value.
The special value \*(lqoff\*(rq turns off the function associated with
The values of variables may be interrogated with the
The variables which may be specified are:
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).
escape character (initially \*(lq^[\*(rq) which causes entry
command mode (when connected to a remote system).
is sent to the remote host.
The initial value for the interrupt character is taken to be
is sent to the remote host.
The initial value for the quit character is taken to be
is sent to the remote host.
The initial value for the flush character is taken to be
is operating in \*(lqcharacter at a time\*(rq mode, then when this
is sent to the remote system.
The initial value for the erase character is taken to be
is operating in \*(lqcharacter at a time\*(rq mode, then when this
is sent to the remote system.
The initial value for the kill character is taken to be
is operating in \*(lqline 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
.B toggle \fIarguments...\fP
various flags that control how
More than one argument may be specified.
The state of these flags may be interrogated with the
above) are recognized locally, and transformed into (hopefully) appropriate
The initial value for this toggle is TRUE in \*(lqline by line\*(rq mode,
and FALSE in \*(lqcharacter at a time\*(rq mode.
characters are recognized (and transformed into
refuses to display any data on the user's terminal
until the remote system acknowledges (via a
that it has processed those
The initial value for this toggle is TRUE if the terminal user had not
done an "stty noflsh", otherwise FALSE (see
above for descriptions of the
characters), the resulting
sequence sent is followed by the
cause the remote system to begin throwing away all previously
typed input until both of the
sequences have been read and acted upon.
The initial value of this toggle is FALSE.
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
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 FALSE.
Toggles socket level debugging (useful only to the
The initial value for this toggle is FALSE.
Toggles the display of some internal
protocol processing (having to do with
The initial value for this toggle is FALSE.
Toggles the display of all network data (in hexadecimal format).
The initial value for this toggle is FALSE.
There is no adequate way for dealing with flow control.
On some remote systems, echo has to be turned off manually when in
\*(lqline by line\*(rq mode.
There is enough settable state to justify a
In \*(lqline by line\*(rq mode, the terminal's
character is only recognized (and sent to the remote system)
when it is the first character on a line.