355 lines
13 KiB
Groff
355 lines
13 KiB
Groff
|
||
|
||
TELNET(1) Minix Programmer's Manual TELNET(1)
|
||
|
||
|
||
NAME
|
||
telnet - user interface to the TELNET protocol
|
||
|
||
SYNOPSIS
|
||
telnet [ host [ port ] ]
|
||
|
||
DESCRIPTION
|
||
Telnet is used to communicate with another host using the TELNET
|
||
protocol. If telnet is invoked without arguments, it enters command
|
||
mode, indicated by its prompt ("telnet>"). In this mode, it accepts and
|
||
executes the commands listed below. If it is invoked with arguments, it
|
||
performs an open command (see below) with those arguments.
|
||
|
||
Once a connection has been opened, telnet enters an input mode. The
|
||
input mode entered will be either "character at a time" or "line by line"
|
||
depending on what the remote system supports.
|
||
|
||
In "character at a time" mode, most text typed is immediately sent to the
|
||
remote host for processing.
|
||
|
||
In "line by line" mode, all text is echoed locally, and (normally) only
|
||
completed lines are sent to the remote host. The "local echo character"
|
||
(initially "^E") may be used to turn off and on the local echo (this
|
||
would mostly be used to enter passwords without the password being
|
||
echoed).
|
||
|
||
In either mode, if the localchars toggle is TRUE (the default in line
|
||
mode; see below), the user's quit, intr, and flush characters are trapped
|
||
locally, and sent as TELNET protocol sequences to the remote side. There
|
||
are options (see toggle autoflush and toggle autosynch below) which cause
|
||
this action to flush subsequent output to the terminal (until the remote
|
||
host acknowledges the TELNET sequence) and flush previous terminal input
|
||
(in the case of quit and intr).
|
||
|
||
While connected to a remote host, telnet command mode may be entered by
|
||
typing the telnet "escape character" (initially "^]"). When in command
|
||
mode, the normal terminal editing conventions are available.
|
||
|
||
COMMANDS
|
||
|
||
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 mode, set, toggle, and display commands).
|
||
|
||
open host [ port ]
|
||
Open a connection to the named host. If no port number is
|
||
specified, telnet will attempt to contact a TELNET server at the
|
||
default port. The host specification may be either a host name (see
|
||
hosts(5)) or an Internet address specified in the "dot notation"
|
||
(see inet(3N)).
|
||
|
||
|
||
5BSD May 10, 1986 1
|
||
|
||
|
||
|
||
TELNET(1) Minix Programmer's Manual TELNET(1)
|
||
|
||
|
||
close
|
||
Close a TELNET session and return to command mode.
|
||
|
||
quit
|
||
Close any open TELNET session and exit telnet. An end of file (in
|
||
command mode) will also close a session and exit.
|
||
|
||
z
|
||
Suspend telnet. This command only works when the user is using the
|
||
csh(1).
|
||
|
||
mode type
|
||
Type is either line (for "line by line" mode) or character (for
|
||
"character at a time" 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 mode will be entered.
|
||
|
||
status
|
||
Show the current status of telnet. This includes the peer one is
|
||
connected to, as well as the current mode.
|
||
|
||
display [ argument... ]
|
||
Displays all, or some, of the set and toggle values (see below).
|
||
|
||
? [ command ]
|
||
Get help. With no arguments, telnet prints a help summary. If a
|
||
command is specified, telnet will print the help information for
|
||
just that command.
|
||
|
||
send 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):
|
||
|
||
escape
|
||
Sends the current telnet escape character (initially "^]").
|
||
|
||
synch
|
||
Sends the TELNET SYNCH sequence. 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 "r" may be echoed on the terminal).
|
||
|
||
brk
|
||
Sends the TELNET BRK (Break) sequence, which may have significance
|
||
to the remote system.
|
||
|
||
|
||
|
||
|
||
|
||
5BSD May 10, 1986 2
|
||
|
||
|
||
|
||
TELNET(1) Minix Programmer's Manual TELNET(1)
|
||
|
||
|
||
ip
|
||
Sends the TELNET IP (Interrupt Process) sequence, which should cause
|
||
the remote system to abort the currently running process.
|
||
|
||
ao
|
||
Sends the TELNET AO (Abort Output) sequence, which should cause the
|
||
remote system to flush all output from the remote system to the
|
||
user's terminal.
|
||
|
||
ayt
|
||
Sends the TELNET AYT (Are You There) sequence, to which the remote
|
||
system may or may not choose to respond.
|
||
|
||
ec
|
||
Sends the TELNET EC (Erase Character) sequence, which should cause
|
||
the remote system to erase the last character entered.
|
||
|
||
el
|
||
Sends the TELNET EL (Erase Line) sequence, which should cause the
|
||
remote system to erase the line currently being entered.
|
||
|
||
ga
|
||
Sends the TELNET GA (Go Ahead) sequence, which likely has no
|
||
significance to the remote system.
|
||
|
||
nop
|
||
Sends the TELNET NOP (No OPeration) sequence.
|
||
|
||
?
|
||
Prints out help information for the send command.
|
||
|
||
set argument value
|
||
Set any one of a number of telnet variables to a specific value.
|
||
The special value "off" turns off the function associated with the
|
||
variable. The values of variables may be interrogated with the
|
||
display command. The variables which may be specified are:
|
||
|
||
echo
|
||
This is the value (initially "^E") which, when in "line by line"
|
||
mode, toggles between doing local echoing of entered characters (for
|
||
normal processing), and suppressing echoing of entered characters
|
||
(for entering, say, a password).
|
||
|
||
escape
|
||
This is the telnet escape character (initially "^[") which causes
|
||
entry into telnet command mode (when connected to a remote system).
|
||
|
||
interrupt
|
||
If telnet is in localchars mode (see toggle localchars below) and
|
||
the interrupt character is typed, a TELNET IP sequence (see send ip
|
||
|
||
|
||
5BSD May 10, 1986 3
|
||
|
||
|
||
|
||
TELNET(1) Minix Programmer's Manual TELNET(1)
|
||
|
||
|
||
above) is sent to the remote host. The initial value for the
|
||
interrupt character is taken to be the terminal's intr character.
|
||
|
||
quit
|
||
If telnet is in localchars mode (see toggle localchars below) and
|
||
the quit character is typed, a TELNET BRK sequence (see send brk
|
||
above) is sent to the remote host. The initial value for the quit
|
||
character is taken to be the terminal's quit character.
|
||
|
||
flushoutput
|
||
If telnet is in localchars mode (see toggle localchars below) and
|
||
the flushoutput character is typed, a TELNET AO sequence (see send
|
||
ao above) is sent to the remote host. The initial value for the
|
||
flush character is taken to be the terminal's flush character.
|
||
|
||
erase
|
||
If telnet is in localchars mode (see toggle localchars below), and
|
||
if telnet is operating in "character at a time" mode, then when this
|
||
character is typed, a TELNET EC sequence (see send ec above) is sent
|
||
to the remote system. The initial value for the erase character is
|
||
taken to be the terminal's erase character.
|
||
|
||
kill
|
||
If telnet is in localchars mode (see toggle localchars below), and
|
||
if telnet is operating in "character at a time" mode, then when this
|
||
character is typed, a TELNET EL sequence (see send el above) is sent
|
||
to the remote system. The initial value for the kill character is
|
||
taken to be the terminal's kill character.
|
||
|
||
eof
|
||
If telnet is operating in "line by line" 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 eof character.
|
||
|
||
toggle arguments...
|
||
Toggle (between TRUE and FALSE) various flags that control how
|
||
telnet responds to events. More than one argument may be specified.
|
||
The state of these flags may be interrogated with the display
|
||
command. Valid arguments are:
|
||
|
||
localchars
|
||
If this is TRUE, then the flush, interrupt, quit, erase, and kill
|
||
characters (see set above) are recognized locally, and transformed
|
||
into (hopefully) appropriate TELNET control sequences (respectively
|
||
ao, ip, brk, ec, and el; see send above). The initial value for
|
||
this toggle is TRUE in "line by line" mode, and FALSE in "character
|
||
at a time" mode.
|
||
|
||
|
||
|
||
|
||
5BSD May 10, 1986 4
|
||
|
||
|
||
|
||
TELNET(1) Minix Programmer's Manual TELNET(1)
|
||
|
||
|
||
autoflush
|
||
If autoflush and localchars are both TRUE, then when the ao, intr,
|
||
or quit characters are recognized (and transformed into TELNET
|
||
sequences; see set above for details), telnet refuses to display any
|
||
data on the user's terminal until the remote system acknowledges
|
||
(via a TELNET Timing Mark option) that it has processed those TELNET
|
||
sequences. The initial value for this toggle is TRUE if the
|
||
terminal user had not done an "stty noflsh", otherwise FALSE (see
|
||
stty(1)).
|
||
|
||
autosynch
|
||
If autosynch and localchars are both TRUE, then when either the intr
|
||
or quit characters is typed (see set above for descriptions of the
|
||
intr and quit characters), the resulting TELNET sequence sent is
|
||
followed by the TELNET SYNCH sequence. This procedure should cause
|
||
the remote system to begin throwing away all previously typed input
|
||
until both of the TELNET sequences have been read and acted upon.
|
||
The initial value of this toggle is FALSE.
|
||
|
||
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 FALSE.
|
||
|
||
debug
|
||
Toggles socket level debugging (useful only to the superuser). The
|
||
initial value for this toggle is FALSE.
|
||
|
||
options
|
||
Toggles the display of some internal telnet protocol processing
|
||
(having to do with TELNET options). The initial value for this
|
||
toggle is FALSE.
|
||
|
||
netdata
|
||
Toggles the display of all network data (in hexadecimal format).
|
||
The initial value for this toggle is FALSE.
|
||
|
||
?
|
||
Displays the legal toggle commands.
|
||
|
||
BUGS
|
||
|
||
There is no adequate way for dealing with flow control.
|
||
|
||
|
||
|
||
|
||
|
||
5BSD May 10, 1986 5
|
||
|
||
|
||
|
||
TELNET(1) Minix Programmer's Manual TELNET(1)
|
||
|
||
|
||
On some remote systems, echo has to be turned off manually when in "line
|
||
by line" mode.
|
||
|
||
There is enough settable state to justify a .telnetrc file.
|
||
|
||
No capability for a .telnetrc file is provided.
|
||
|
||
In "line by line" mode, the terminal's eof character is only recognized
|
||
(and sent to the remote system) when it is the first character on a line.
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
5BSD May 10, 1986 6
|
||
|