How to exit from telnet linux

Как мне выйти из telnet?

Я начинаю телнет telnet host port . Как мне остановить это в Windows? Шокирующе, Ctrl + C не работает.

Он должен был напечатать что-то вроде:

Так как ^X есть Ctrl X , попробуйте Ctrl ] для ^] .

Затем вы должны войти в консоль telnet, куда вы можете войти, quit чтобы выйти из telnet.

Тип quit для выхода из Telnet в Windows.

^] Средство ctrl + правая скобка. Как это ни странно, это работает. Вы попадете в подсказку telnet, где вы можете ввести quit .

На международных клавиатурах символ] часто не является одной клавишей, и его необходимо заменить другой клавишей. Правильный ключ обычно является ключом справа от P или следующим ключом после этого.

Вот список, основанный на комментариях ниже:

• Финский, шведский, норвежский, датский: ctrl + å
• Французский: ctrl + 6
• Немецкий: ctrl + ü
• Швейцарец: ctrl + ¨
• Венгерский: ctrl + 5
• Португальский: ctrl + ´
• Голландский, бельгийский: ctrl + $
• Канадский французский: ctrl + ç

Цитата @jtbandes ответ здесь: https://superuser.com/a/427/192525 Все кредиты ему.

PS: Ответ воспроизведен здесь для вашего удобства, так как Google сначала взял меня на этот вопрос, и ни один из других ответов здесь не был достаточным для моего случая. Вопрос Как отправить escape-символ на OS X терминал? можно рассматривать как дубликат (более общий вариант) этого вопроса, поскольку проблемы ОП в основном одинаковы.

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Telnet — How Do I End a Telnet Session (Windows, Linux, Mac)

How do I close a telnet session/window?

This article assumes that you’ve started a telnet connection through the Windows command prompt (you can do so by typing: «telnet address port»).

Answer: To end your current telnet session you must reach the telnet prompt and type quit.

Here are the steps for doing so:

1. Open the telnet prompt by holding down the ‘Ctrl’ key and push the ‘]’ key. (prompt: Microsoft Telnet>)
2. Type quit.
3. Push the ‘Enter’ key.

You can change this default telnet prompt key by starting telnet like this: telnet –e p 192.168.1.81(this will change the telnet prompt key to lowercase ‘p’)

12 Responses to “How to end a telnet session (Windows, Linux, Mac)”

Nik says: Hey, Thanks a lot. I had opened a telnet connection and had no idea how to close it until I came across this! By the way, I am logged in Ubuntu. So the steps you have mentioned for windows work for linux as well.

January 1, 2010 at 2:05 am (Edit)

Cpascu says: Good to know, changed the title accordingly 🙂

January 12, 2010 at 11:36 am (Edit)

Thomas says: Hi, great post, could you please mention, that this also work with other key mappings? e.g. on german keyboards the ‘]’ is a composed key, but the same key position as on english keyboards works: use [Ctrl] + [+] there. Regards, Thomas

January 28, 2010 at 12:20 am (Edit)

M L Sreekanth says: THANKS ALOT…… Every time i used to close the window or putty to come out of the session.

May 7, 2010 at 2:59 am (Edit)

Jimmy says: This is HELPFUL! I’m on mac OS X 10.6.6 and the same key commands work to get the prompt so that you can properly close the window. You could add Mac to the title of the page, too! Thanks!

February 17, 2011 at 5:28 am (Edit)

Neetish Jehra says : Thanks very handy!

May 31, 2011 at 3:26 pm (Edit)

Omo Olorun says: Nic eone, thanks.

July 3, 2011 at 11:46 pm (Edit)

Sameet says: So I am curious as to What Ctrl+C does not do that this does or are they the same. What I am trying to get at is does Ctrl+C leave open/lingering connections

November 26, 2013 at 8:48 am (Edit)

Uro says: For non English keyboard you can press and hold Alt key then enter 29 on num keypad. This will send ‘^]’ control character to the terminal according to the ASCII table.

December 17, 2013 at 3:56 am (Edit)

Shilpa says: How to kill a telnet session, when the telnet console window is closed mistakenly.

August 27, 2014 at 3:47 am (Edit)

Nene says: Thanks a lot, it helped me a lot.

September 30, 2014 at 7:25 am (Edit)

MJ says: in linux, I type echo|telnet server_ip tcp_port this will help me not to enter the escape character but will end the telnet session be it good or bad. What is similar option in windows?

February 17, 2016 at 4:00 am (Edit)

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How to close telnet terminal in Linux and Windows (quit, exit not working)? Example

The telnet is one of the most useful Linux networking commands, which is used to check if a server is listening on a particular port and it’s whether up and running or not, but it’s a little bit tricky to use, especially, if you are not using it on daily basis. Though I have used telnet before, when I use it after a long time, I actually forgot how to close the telnet terminal and how to get out of it. I tried every possible Linux commands I can think of which is used to close, cancel a command, or exit from VIM editor in UNIX, like Ctrl + C, quit, exit, q! and even the escape character ‘^]’, only to realize that nothing is working. It may sound silly that an experienced developer cannot even come out of a telnet terminal but this is a true story.

What I have noticed in general is that, even though we learn new things when our experience grows, we actually forget something equally important as well, particularly if we don’t use that thing or command on daily basis.

Our mind is trained to keep only important stuff in memory, if a particular thing, particular knowledge or concept is not used for a long time and doesn’t find very important something like life or death, it slowly offloads it. The trick here is to revise and reuse it once in a while.

I finally managed to come out from the telnet command prompt after a bit of struggle, and trial and error but I was surprised how difficult it can be to use one of the top 10 networking commands in UNIX.

So, not to forget again and to help anyone who is stuck in the same situation, I decided to share my thoughts in this post.

Let’s see the exact command to close the telnet terminal in Linux and Windows 10. Though, keep referring a good UNIX command course like Linux Command Line Basics not to forget important commands like telnet.

How to close telnet terminal in Linux and Windows

Before looking at how to come out of the telnet command prompt, let’s first look at how not paying enough attention and thinking that every command will work same way can confuse you easily.

You can see below that I had tried everything I could to come out of telnet windows but nothing worked, but had I paid attention to the telnet message that » Escape character is ‘^]'» , I would have probably been able to come out of telnet terminal earlier.

The trick here is you need to first type escape character e.g. ‘^]’ which is ‘Ctrl + ]’ and then type quit to close the telnet terminal in Linux or any UNIX system.

I expect the same command will work on Windows and Mac also as telnet is ubiquitous and you will find telnet command in a host of the operating system including the big three e.g. Linux, Windows, and Mac. See these Best Websites to learn Linux for FREE to learn more about basic commands like telnet command in UNIX/Linux.

Here are the exact steps to end a telnet session in Linux and Windows :

1. Open the telnet prompt by holding down the ‘Ctrl’ key and push the ‘]’ key. (prompt: Microsoft Telnet>)
2. Type quit.
3. Push the ‘Enter’ key.

The telnet is an extremely useful command and is used a lot in client-server applications e.g. you can use this to solve connection refused error in Java, which is mostly due to incorrect client-server communication.

In the electronic trading and FIX protocol world, telnet is a great tool to diagnose FIX session connection issues as described in this article.

You can even use telnet to check if your own HTTP server is running or not as I have discussed when talked about building HTTP server in Java, here.

That’s all about how to exit from the telnet terminal on Windows or Linux. As I told its one of the must-know networking commands and is available on almost all operating system. When you don’t use it regularly sometimes it becomes tricky to operate as shown in this article, but just remember that you need to first type escape character to actually type command in telnet, while it is connected to a server.

Other Linux command tutorials for Java Programmers

• 10 examples of lsof commands in UNIX (examples)
• 10 basic networking commands in Linux (list)
• How to send an HTTP request from the Linux command prompt? (command)
• 10 examples of chmod command in UNIX (examples)
• 10 examples of xargs command in UNIX? (examples)
• 10 UNIX and Linux command-based questions from Interviews (list)
• 10 Examples of curl command in Linux (examples)
• 5 Courses to learn Bash Scripting in Linux (Courses)
• How to find the largest file and directory in Linux (tutorial)
• How to find which process is using a port in Linux (tutorial)
• 10 Tips to work fast in Linux (tips)
• 5 Free Courses to Learn Linux Online (courses)
• Practical Guide to Linux Commands (book)

Thanks for reading this article so far. If you like these Linux command tutorial then please share with your friends and colleagues. If you have any questions or feedback then please dro a note.

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Quitting telnet on Linux

Standard escape character is CTRL-] on telnet.

says that on Hungarian keyboard it is CTRL-5.

On my student’s terminal it works. On my terminal CTRL-5 displays

and does not go into the

prompt. What setting hinders me to escape telnet this way?

EDIT: I omitted one key ingredient: I use MobaXTerm. I tried on putty and CTRL-5 worked with 5 from the alphanumeric keyboard. MobaXTerm might swallow CTRL-5.

1 Answer 1

Press the correct 5 key.

There are two 5 keys on your keyboard, one at position E05 and one on the numeric keypad, wherever that happens to be (either a separate keypad or an overlain keypad accessible with a Fn key or similar). You are pressing the wrong one.

It does not matter that you have a Hungarian keyboard. The engravings on the keytops do not control what actions the keys cause. What matters is that you are using a Hungarian keyboard mapping such as hu101.kmap (on Linux operating systems).

In that keyboard mapping only one of the 5 keys produces the ␝ character in conjunction with the ⎈ Control modifier, the key at position E05. ␝ is of course the local escape sequence for the telnet program.

In that keyboard mapping the other 5 key, on the numeric keypad, produces the XTerm control sequence CSI 1 ; 5 u that you are seeing; which denotes the 5 key on the numeric keypad, in «application mode», occurring once, with the ⎈ Control modifier.

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Linux telnet command

Description

The telnet command is used for interactive communication with another host using the TELNET protocol. It begins in command mode, where it prints a telnet command prompt («telnet>«).

If telnet is invoked with a host argument, it performs an open command implicitly (see the Commands section below for details).

Syntax

Options

-4	Force IPv4 address resolution.
-6	Force IPv6 address resolution.
-8	Request 8-bit operation. This option causes an attempt to negotiate the TELNET BINARY option for both input and output. By default, telnet is not «8-bit clean» (it does not recognize 8-bit character encodings such as Unicode).
-E	Disables the escape character functionality; that is, sets the escape character to «no character».
-L	Specifies an 8-bit data path on output. This option causes the TELNET BINARY option to be negotiated on output.
-a	Attempt automatic login. Currently, this sends the username via the USER variable of the ENVIRON option if supported by the remote system. The username is retrieved via the getlogin system call.
-b address	Use bind on the local socket to bind it to a specific local address.
-d	Sets the initial value of the debug toggle to TRUE.
-r	Emulate rlogin. In this mode, the default escape character is a tilde. Also, the interpretation of the escape character is changed: an escape character followed by a dot causes telnet to disconnect from the remote host. A ^Z (Control-Z) instead of a dot suspends telnet, and a ^] (Control-close bracket, the default telnet escape character) generates a normal telnet prompt. These codes are accepted only at the beginning of a line.
-S tos	Sets the IP TOS (type-of-service) option for the telnet connection to the value tos.
-e escapechar	Sets the escape character to escapechar. If no character is supplied, no escape character will be used. Entering the escape character while connected causes telnet to drop to command mode.
-l user	Specify user as the user to log in as on the remote system. By sending the specified name as the USER environment variable, so it requires that the remote system support the TELNET ENVIRON option. This option implies the -a option, and may also be used with the open command.
-n tracefile	Opens tracefile for recording trace information. See the set tracefile command below.
host	Specifies a host to contact over the network.
port	Specifies a port number or service name to contact. If not specified, the telnet port (23) is used.

Protocol

Once a connection is opened, telnet attempts to enable the TELNET LINEMODE option. If this fails, then telnet will revert to one of two input modes: either «character at a time» or «old line by line» depending on what the remote system supports.

When LINEMODE is enabled, character processing is done on the local system, under the control of the remote system. When input editing or character echoing is to be disabled, the remote system will relay that information. The remote system also relays changes to any special characters that happen on the remote system, so that they can take effect on the local system.

In «character at a time» mode, most text typed is immediately sent to the remote host for processing.

In «old 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).

If the LINEMODE option is enabled, or if the localchars toggle is TRUE (the default for «old line by line»; see below), the user’s quit, intr, and flush characters are trapped locally, and sent as TELNET protocol sequences to the remote side. If LINEMODE has ever been enabled, then the user’s susp and eof are also sent as TELNET protocol sequences, and quit is sent as a TELNET ABORT instead of BREAK. 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).

Commands

The following telnet commands are available. Unique prefixes are understood as abbreviations.

auth argument .	The auth command controls the TELNET AUTHENTICATE protocol option. If telnet was compiled without authentication, the auth command is not supported. Valid arguments are as follows: disable type Disable the specified type of authentication. To obtain a list of available types, use the auth disable ? command. enable type Enable the specified type of authentication. To obtain a list of available types, use the auth enable ? command. status List the current status of the various types of authentication. Note that the current version of telnet does not support authentication.
close	Close the connection to the remote host, if any, and return to command mode.
display argument .	Display all, or some, of the set and toggle values (see below).
encrypt argument .	The encrypt command controls the TELNET ENCRYPT protocol option. If telnet was compiled without encryption, the encrypt command will not be supported. Valid arguments are as follows: disable type [input|output] Disable the specified type of encryption. If you do not specify input or output, encryption of both is disabled. To obtain a list of available types, use «encrypt disable ?«. enable type [input|output] Enable the specified type of encryption. If you do not specify input or output, encryption of both is enabled. To obtain a list of available types, use «encrypt enable ?«. input This argument is the same as «encrypt start input«. -input This argument is the same as «encrypt stop input«. output This argument is the same as «encrypt start output«. -output This argument is the same as «encrypt stop output«. start [input|output] Attempt to begin encrypting. If you do not specify input or output, encryption of both input and output is started. status Display the current status of the encryption module. stop [input|output] Stop encrypting. If you do not specify input or output, encryption of both is stopped. type type Sets the default type of encryption to be used with later «encrypt start» or «encrypt stop» commands. Note that the current version of telnet does not support encryption.
environ arguments.	The environ command is used to propagate environment variables across the telnet link using the TELNET ENVIRON protocol option. All variables exported from the shell are defined, but only the DISPLAY and PRINTER variables are marked to be sent by default. The USER variable is marked to be sent if the -a or -l command-line options were used. Valid arguments for the environ command are: define variable value Define the variable to have a value of value. Any variables defined by this command are automatically marked for propagation («exported»). The value may be enclosed in single or double quotes so that tabs and spaces may be included. undefine variable Remove any existing definition of variable. export variable Mark the specified variable for propagation to the remote host. unexport variable Do not mark the specified variable for propagation to the remote host. The remote host may still ask explicitly for variables that are not exported. list List the current set of environment variables. Those marked with an asterisk («*«) will be propagated to the remote host. The remote host may still ask explicitly for the rest. ? Prints out help information for the environ command.
logout	Send the TELNET LOGOUT protocol option to the remote host. This command is similar to a close command. If the remote host does not support the LOGOUT option, nothing happens. But if it does, this command should cause it to close the connection. If the remote side also supports the concept of suspending a user’s session for later reattachment, the logout command indicates that the session should be terminated immediately.
mode type	The type is one of several options, depending on the state of the session. telnet asks the remote host to go into the requested mode. If the remote host says it can, that mode takes effect. Options for type are as follows: character Disable the TELNET LINEMODE option, or, if the remote side does not understand the LINEMODE option, then enter «character at a time» mode. line Enable the TELNET LINEMODE option, or, if the remote side does not understand the LINEMODE option, then attempt to enter «old-line-by-line» mode. isig (-isig) Attempt to enable (disable) the TRAPSIG mode of the LINEMODE option. This requires that the LINEMODE option be enabled. edit (-edit) Attempt to enable (disable) the EDIT mode of the LINEMODE option. This requires that the LINEMODE option be enabled. softtabs (-softtabs) Attempt to enable (disable) the SOFT_TAB mode of the LINEMODE option. This requires that the LINEMODE option be enabled. litecho (-litecho) Attempt to enable (disable) the LIT_ECHO mode of the LINEMODE option. This requires that the LINEMODE option be enabled. ? Prints out help information for the mode command.
open host [[-l] user][— port]	Open a connection to the named host. If no port number is specified, telnet attempts to contact a telnet daemon at the standard port (23). The host specification may be a hostname or IP address. The -l option may be used to specify a username to be passed to the remote system, like the -l command-line option. When connecting to ports other than the telnet port, telnet does not attempt telnet protocol negotiations. This method of connecting makes it possible to connect to services that do not support the telnet protocol without making a mess. Protocol negotiation can be forced by placing a dash before the port number. After establishing a connection, any commands associated with the remote host in /etc/telnetrc and the user’s .telnetrc file are executed, in that order. The format of the telnetrc files is as follows: Lines beginning with a #, and blank lines, are treated as comments (ignored). The rest of the file should consist of hostnames and sequences of telnet commands to use with that host. Commands should be one per line, indented by whitespace; lines beginning without whitespace are interpreted as hostnames. Lines beginning with the special hostname ‘DEFAULT’ will apply to all hosts. Hostnames including ‘DEFAULT’ may be followed immediately by a colon and a port number or string. If a port is specified it must match exactly with what is specified on the command line. If no port was specified on the command line, then the value ‘telnet’ is used. Upon connecting to a particular host, the commands associated with that host are executed.
quit	Close any open session and exit telnet. An end of file condition on input, when in command mode, will trigger this operation as well.
send arguments	Send one or more special telnet protocol character sequences to the remote host. The following are the codes which may be specified (more than one may be used in one command): abort Sends the TELNET ABORT (abort processes) sequence. 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, that the remote system may or may not choose to respond. brk Sends the TELNET BRK (break) sequence, which may have significance to the remote system. 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. eof Sends the TELNET EOF (end-of-file) sequence. eor Sends the TELNET EOR (end-of-record) sequence. escape Sends the current telnet escape character. ga Sends the TELNET GA (go ahead) sequence, which likely has no significance to the remote system. getstatus If the remote side supports the TELNET STATUS command, getstatus sends the subnegotiation to request that the server send its current option status. ip Sends the TELNET IP (interrupt [rocess) sequence, which should cause the remote system to abort the currently running process. nop Sends the TELNET NOP (no operation) sequence. susp Sends the TELNET SUSP (duspend process) sequence. 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 lowercase «r» may be echoed on the terminal). do cmd Sends the TELNET DO cmd sequence. The cmd can be either a decimal number between 0 and 255, or a symbolic name for a specific TELNET command. The cmd can also be either help or ? to print out help information, including a list of known symbolic names. dont cmd, will cmd, wont cmd Similar to do. ? Prints out help information for the send command.
set argument value, unset argument value	The set command will set any one of the telnet variables to a specific value or as TRUE. The special value off turns off the function associated with the variable. This command is equivalent to using the unset command. The unset command will disable or set to FALSE any of the specified variables. The values of variables may be interrogated with the display command. The variables which may be set or unset, but not toggled, are listed here. Also, any of the variables for the toggle command may be explicitly set or unset. ayt If telnet is in localchars mode, or LINEMODE is enabled, and the status character is typed, a TELNET AYT sequence is sent to the remote host. The initial value for the «Are You There» character is the terminal’s status character. echo This variable 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). eof If telnet is operating in LINEMODE or «old line by line» mode, entering this character as the first character on a line causes 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. 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. escape This variable is the telnet escape character (initially «^[«) which causes entry into telnet command mode (when connected to a remote system). 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. forw1, forw2 If telnet is operating in 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. interrupt If telnet is in localchars mode (see toggle localchars below) and the interrupt character is typed, a TELNET IP sequence (see send ip above) is sent to the remote host. The initial value for the interrupt character is taken to be the terminal’s intr 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. lnext If telnet is operating in LINEMODE or «old line by line» mode, then this character is taken to be the terminal’s lnext character. The initial value for the lnext character is taken to be the terminal’s lnext 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. reprint If telnet is operating in LINEMODE or «old line by line» mode, then this character is taken to be the terminal’s reprint character. The initial value for the reprint character is taken to be the terminal’s reprint character. rlogin This variable is the rlogin mode escape character. Setting it enables rlogin mode, as with the r command-line option (see above). start If the TELNET TOGGLE-FLOW-CONTROL option is enabled, then this character is taken to be the terminal’s start character. The initial value for the kill character is taken to be the terminal’s start character. stop If the TELNET TOGGLE-FLOW-CONTROL option is enabled, then this character is taken to be the terminal’s stop character. The initial value for the kill character is taken to be the terminal’s stop character. susp If telnet is in localchars mode, or LINEMODE is enabled, and the suspend character is typed, a TELNET SUSP sequence (see send susp above) is sent to the remote host. The initial value for the suspend character is taken to be the terminal’s suspend character. tracefile This variable is the file where the output, caused by netdata or option tracing being TRUE, will be written. If it is set to «—«, then tracing information will be written to standard output (this is the default). worderase If telnet is operating in LINEMODE or «old line by line» mode, then this character is taken to be the terminal’s worderase character. The initial value for the worderase character is taken to be the terminal’s worderase character. ? Displays the legal set (or unset) commands.
slc state	The slc command (set local characters) is used to set or change the state of the special characters when the TELNET LINEMODE option is enabled. Special characters are characters that get mapped to TELNET commands sequences (like ip or quit) or line editing characters (like erase and kill). By default, the local special characters are exported. state may be one of the following: 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 switches to the remote value. export Switch to the local defaults for the special characters. The local default characters are those of the local terminal at the time when telnet was started. 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 TELNET connection was established. ? Prints out help information for the slc command.
status	Show the current status of telnet. This command includes the name of the remote host, if any, and the current mode.
toggle arguments .	Toggle (between TRUE and FALSE) various flags that control how telnet responds to events. These flags may be set explicitly to TRUE or FALSE using the set and unset commands. More than one flag may be toggled at once. The state of these flags may be examined with the display command. Valid flags are: authdebug Turns on debugging for the authentication code. This flag only exists if authentication support is enabled. autoflush If autoflush and localchars are both TRUE, then when the ao, 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). autoencrypt, autodecrypt When the TELNET ENCRYPT option is negotiated, by default the actual encryption (or decryption) of the data stream does not start automatically. The autoencrypt (or autodecrypt) command states that encryption of the output (input) stream should be enabled as soon as possible. Note that this flag exists only if encryption support is enabled. autologin If the remote side supports the TELNET AUTHENTICATION option, telnet attempts to use it to perform automatic authentication. If the TELNET AUTHENTICATION option is not supported, the user’s login name is propagated using the TELNET ENVIRON option. Setting this flag is the same as specifying the «a» option to the open command or on the command line. 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 are read and acted upon. The initial value of this toggle is FALSE. binary Enable or disable the TELNET BINARY option on both input and output. inbinary Enable or disable the TELNET BINARY option on input. outbinary Enable or disable the TELNET BINARY option on output. crlf If this is TRUE, then carriage returns will be sent as CR LF. If this is FALSE, then carriage returns will be send as CR NUL. The initial value for 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. encdebug Turns on debugging information for the encryption code. Note that this flag only exists if encryption support is available. 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 «old line by line» mode, and FALSE in «character at a time» mode. When the LINEMODE option is enabled, the value of localchars is ignored, and assumed to always be TRUE. If LINEMODE has ever been enabled, then quit is sent as abort, and eof and are sent as eof and susp; see send above). netdata Toggles the display of all network data (in hexadecimal format). 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. prettydump When the netdata toggle is enabled, if prettydump is enabled the output from the netdata command will be formatted in a more user-readable format. Spaces are put between each character in the output, and the beginning of telnet escape sequences are preceded by an asterisk («*«) to aid in locating them. skiprc When the skiprc toggle is TRUE, telnet does not read the telnetrc files. The initial value for this toggle is FALSE. termdata Toggles the display of all terminal data (in hexadecimal format). The initial value for this toggle is FALSE. verbose_encrypt When the verbose_encrypt toggle is TRUE, TELNET prints out a message each time encryption is enabled or disabled. The initial value for this toggle is FALSE. This flag only exists if encryption support is available. ? Displays the legal toggle commands.
z	Suspend telnet. This command only works when the user uses the C Shell (csh).
! [command]	Execute a single command in a subshell on the local system. If command is omitted, then an interactive subshell is invoked.
? [command]	Get help. With no arguments, telnet prints a help summary. If a command is specified, telnet prints the help information for that command.

Environment

telnet uses at least the HOME, SHELL, DISPLAY, and TERM environment variables. Other environment variables may be propagated to the other side via the TELNET ENVIRON option.

Files

/etc/telnetrc	global telnet startup values
/.telnetrc	user customized telnet startup values

Examples

Attempts to open a connection to the remote host myhost.com. If a connection is established, the host prompts for a login name and password.

Attempts to open a connection to the remote host myhost.com on port 5555, using the login name myusername. If successful, the host prompts for myusername‘s password.

Opens a local telnet> prompt, where you can enter any of the commands listed above. For example, entering the following command at the prompt:

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