The Virtual Terminal Protocol (TELNET) provides connections to remote hosts. With it, you can access remote hosts using OpenVMS commands or a UNIX style command interface.
You can run the Telnet client interactively or through a startup command procedure.
Before you use TELNET, ask your system manager if the TELNET software was installed, configured, and started on your system.
· Before you can connect to a remote host, you need to know:
· The name of the remote host to which you want to connect.
· The username and password for each account on the remote host. If the remote host does not support multiuser protection features, you may not need a username and password.
· How to use the operating system of the remote host.
|
Note: The Telnet client does not restrict the ASCII character set to seven-bit ASCII as the TELNET standard implies. The Telnet client supports the full eight-bit (multinational) character set. To use the multinational character set, you must configure your terminal to support eight-bit characters. The peer TELNET implementation must also support the same.
|
Run the Telnet client utility to connect to a remote host. The Telnet client supports as many as 10 connected sessions at any one time. To open a TELNET session (see the below example):
1. At the DCL prompt, enter:
$ TELNET
a. Use the OPEN command to open a remote TELNET session. At the TELNET> prompt, enter:
TELNET>OPEN host
host is the name of the host to which you want to connect.
2. Respond to the login prompts, if any, of the remote host.
3. Open another session if desired:
a. Return to the local TELNET> prompt by entering the escape sequence displayed when opening the connection (usually Ctrl+\). The previous session remains open.
b. Use the OPEN command to open the next session. Repeat steps 2 and 3.
You can also open a remote TELNET connection as follows:
$ TELNET host
Example showing the opening of multiple telnet connections:
(IRIS) $ TELNET
TELNET>OPEN BART
%TCPWARE_TELNET-I-TRYING, trying bart.example.com,telnet(192.168.1.92,23)...
%TCPWARE_TELNET-I-ESCAPE, escape (attention) character is "^\"
(BART) $ Ctrl+\
TELNET> OPEN MARGE
[BART remains open]
%TCPWARE_TELNET-I-TRYING,
trying marge.example.com,telnet
(192.168.1.91,23)...
%TCPWARE_TELNET-I-ESCAPE, escape character is "^\"
(MARGE) $ Ctrl+\
TELNET>OPEN HOMER
[BART and MARGE remain open]
%TCPWARE_TELNET-I-TRYING,
trying homer.example.com,telnet
(192.168.1.90,23)...
%TCPWARE_TELNET-I-ESCAPE, escape character is "^\"
(HOMER) $ Ctrl+\
TELNET> OPEN LISA [BART,
MARGE, and HOMER remain open]
%TCPWARE_TELNET-I-TRYING,
trying lisa.example.com,telnet
(192.168.1.89,23)...
%TCPWARE_TELNET-I-ESCAPE, escape character is "^\"
(LISA) $ Ctrl+\
TELNET>
A TELNET session remains open until you log out of that session at the system prompt or use the CLOSE, EXIT, QUIT, or BYE commands or enter Ctrl+Z at the TELNET> prompt.
To close a TELNET session, use one of the following commands at the TELNET> prompt (see the below example):
· TELNET>CLOSE closes the current session, as in the following chart:
|
If you open a TELNET session using... |
And... |
Then CLOSE closes the current session and... |
|
TELNET>OPEN host |
It is the only session There are other sessions |
Keeps you in TELNET Keeps you in TELNET with the other sessions open |
|
$ TELNET host |
It is the only session There are other sessions |
Exits TELNET Keeps you in TELNET with the other sessions open |
If you close the current session, and there are other connected sessions, the Telnet client resets the current session to the "next" session.
· TELNET>CLOSE session-number closes only the specified session, as indicated by the SHOW STATUS command.
· TELNET>EXIT exits TELNET
· TELNET>QUIT exits TELNET
· TELNET>BYE exits TELNET
· TELNET>Ctrl+Z interrupts TELNET
(IRIS) $ TELNET
TELNET>OPEN BART
%TCPWARE_TELNET-I-TRYING, trying bart.example.com,telnet(192.168.1.92,23)... %TCPWARE_TELNET-I-ESCAPE, escape character is "^\"
(BART) $ Ctrl+\
TELNET> OPEN
MARGE [BART remains open]
%TCPWARE_TELNET-I-TRYING,trying marge.example.com,telnet(192.168.1.91,23)...
%TCPWARE_TELNET-I-ESCAPE, escape character is "^\"
(MARGE) $ Ctrl+\
TELNET>SHOW STATUS
The Telnet client V6.1-0
Copyright (c) Process Software
Connected sessions:
1. bart.example.com,telnet (192.168.1.92,23).
--> 2. marge.example.com, telnet (192.168.1.91,23).
"^\" is the escape (attention) character
TELNET> CLOSE 2
%TCPWARE_TELNET-I-CONNCLOSED,
closing session 2, marge.example.com
TELNET>CLOSE 1
%TCPWARE_TELNET-S-CONNCLOSED,
closing session 1, bart.example.com
TELNET>EXIT
(IRIS) $
You can issue commands to the Telnet client utility during a remote session by returning to the TELNET> prompt. You can then enter one or more TELNET commands.
TELNET OpenVMS features multiline recall of up to 20 command lines using the standard OpenVMS line recall and editing keys.
You return to the remote session by entering the RESUME command.
To issue a local TELNET command while connected to a remote host and then resume the session on the host (see the below example):
1. Enter the escape (attention) character to return to the TELNET prompt: for example: Ctrl+\
2. Issue a TELNET command. For example, you may want to:
· Issue the SHOW STATUS command. The SHOW STATUS command displays a list of open connections. The arrow (-->) identifies the current session.
· Change the escape (attention) character using the SET ESCAPE command.
3. Return to the remote host by entering:
TELNET>RESUME
This command resumes to the current remote host. Pressing Return or entering the OPEN command also resumes to the current remote host.
To resume to a different session, enter:
TELNET>RESUME session-number
session-number is the number of the session which you want to resume. The session-number refers to a particular connection, as displayed by the SHOW STATUS command.
You can switch between local TELNET command mode and the remote host as often as you like.
(BART) $ Ctrl+\
TELNET>SHOW STATUS
Telnet client V6.1 Copyright
(c) Process Software
Connected sessions:
1. BART.example.com, telnet (192.168.1.92,23).
2. HOMER.example.com, telnet (192.168.1.90,23).
3. MARGE.example.com, telnet (192.168.1.91,23).
--> 4. LISA.example.com, telnet (192.168.1.89,23).
"^\" is the escape (attention) character.
TELNET>SET ESCAPE "^A"
escape (attention) character is "^A"
TELNET>RESUME
(BART) $
(BART) $ Ctrl+\
TELNET>RESUME 2
%TCPWARE_TELNET-I-RESUME,
resuming session 2, HOMER.example.com
(HOMER) $
You can run applications over a TELNET connection by creating an NTA terminal on the local client. You can only create such devices from TELNET with no other escaped connection. This section describes how to create non-permanent NTA devices. To create permanent NTA devices, see the next section.
Normally, the Telnet client connects to an NTA device at the TCPware server end of the connection. It does not usually create a local NTA device. However, you can create a local NTA device so that you can run applications over the TELNET connection. To create a local NTA device (see the below example):
1. Enter at the DCL prompt one of the following:
· $ TELNET host /CREATE
· TELNET>OPEN /CREATE
Use the second method if you already logged in to a host and escaped from the session (using Ctrl+\ or some other defined escape sequence).
In both cases, this associates a pre-allocated local NTAx: terminal device to your TELNET connection; x is the next available unit number. No other escaped connection can exist during your TELNET session for this to work. (If one exists, the %TCPWARE_TELNET-E-CONNOPN error message appears.)
2. Run your application at the DCL prompt. Use the allocated terminal device as desired.
3. When your application ends, clean up by deallocating the NTA device you created using the following command at the DCL prompt: $ DEALLOCATE device
See your OpenVMS documentation for details on the DEALLOCATE command.
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Note: Using /CREATE in this way creates a non-permanent NTA device, which has certain ramifications. See the next section for details on how to create a permanent NTA device. Using the OPEN /CREATE command as part of a TELNET command file creates an NTA device and exits TELNET right away without passing any further commands in the file to TELNET.
|
You can also invoke TELNET and use OPEN/CREATE non-interactively, such as with a batch file. The batch file cannot open an interactive connection. For applications run by the creating process, use the /LOGICAL qualifier to create a predefined name for the device. If this device is to be used by another process, the qualifier /LOGICAL=... /TABLE= may help reference it. For example:
$ TELNET SIGMA /CREATE /LOGICAL=TELNET_NTA /TABLE=SYSTEM /MODE=EXEC
See the OPEN command in the Command Reference section of this chapter for other parameters you can use with the /CREATE qualifier.
Opening a TELNET Connection to a Terminal Device:
$ TELNET MARGE /CREATE
%TCPWARE_TELNET-I-TRYING,
trying marge.example.com,telnet
(192.168.1.91,23)...
%TCPWARE_TELNET-I-ALOC,_MARGE$NTA1: allocated
$ SET HOST/DTE NTA1:
$ DEALLOCATE NTA1:
$ TELNET BART
%REM-I-TOQUIT, connection established
Press Ctrl/\ to quit, Ctrl/@ for command mode
OpenVMS 8.4 with TCPware for OpenVMS 6.1
Username: Ctrl+\
TELNET>OPEN /CREATE
%TCPWARE_TELNET-I-ALLOC, _NTA1: allocated
$ SET HOST/DTE NTA1:
$ DEALLOCATE NTA1:
You can also run applications over a TELNET connection by creating a permanent NTA terminal on the local client. This permanent device acts more like a LAT device; it is not automatically deleted when there are no process channels assigned to it, it can be handed off to other applications, and it has reconnect capabilities in case of a connection break. This section describes how to create permanent NTA devices. To create non-permanent NTA devices, see the previous section.
Using TELNET /CREATE by itself to create a non-permanent NTA device, such as in the previous section, has the following limitations:
· An application using this NTA device may be written to deassign and thus delete the device if the connection goes down. This could cause a conflict when rerunning the application if, meanwhile, another NTA connection with the same unit number is created.
· Handing off the NTA device to another process may require setting up the device as NOHANGUP.
· Recovery is not possible in case of a broken connection.
You can bypass these limitations and make the NTA device a permanent one by adding the PERMANENT keyword to the TELNET /CREATE command, as follows (see the following example):
|
Note: Creating a permanent NTA device requires OPER privilege.
|
1. Enter at the DCL prompt:
$ TELNET host port /CREATE=PERMANENT
or:
TELNET>OPEN host port /CREATE=PERMANENT
This creates a permanent local NTAx: terminal device with the next available unit number. However, unlike non-permanent NTA devices, the TELNET utility does not pre-allocate it. Likewise, you can specify the /LOGICAL qualifier to set up a logical name for the device so that other applications can use it.
It is advisable that you specify a port other than the default TELNET port 23.
See the OPEN command in the Command Reference section of this chapter for other parameters you can use with the /CREATE=PERMANENT qualifier.
2. Run your application at the DCL prompt, as with a non-permanent NTA device. The difference is that handing off the NTA device to another process and recovery of a broken connection are enhanced.
3. In handing off the NTA device to another process, you may wish to change its protection:
· In VMS 5, use SET PROTECTION, or SET DEVICE /ACL
· VMS 6 and higher replaces these commands with SET SECURITY /PROTECTION= /ACL
Setting up a Permanent NTA Device:
TELNET>OPEN MARGE 7 /LOGICAL=MY_PORT
-
_TELNET>/CREATE=(PERMANENT,INTERVAL=10,RETRIES=10)
%TCPWARE_TELNET-I-CREATED, _NTA1: created
$ @MY_APPLICATION MY_PORT
If the connection to the remote port is broken, a temporary NTA device is reported as "Offline" with $QIO's failing with a SS$_DEVOFFLINE status. For a permanent NTA device, however:
· The NTA devchar is marked UNAVAILABLE (which can be viewed by using SYS$GETDVI to check if DVI$_DEVCHAR's DEV$V_AVL = 0).
· If a terminal Ctrl+Y AST is set up, the AST fires up. (Setup: Disable Ctrl+Y handling by DCL using LIB$DISABLE_CTRL( &LIB$M_CLI_CTRLY, 0 ), and set up the AST using SYS$QIOW with IO$_SETMODE | IO$M_CTRLYAST).
· Terminal I/Os queued in the TTdriver are completed with the I/O Status Block (IOSB) having a status of SS$_HANGUP.
· A new write $QIO buffers the data so that it can be sent when reconnected. If no reconnection is being done, then one is set up.
· Data sent at the time of the broken connection may be lost.
·
The client attempts to reconnect to the remote port as described
in the
OPEN /CREATE=PERMANENT command section.
· The permanent NTA handles reconnects internally instead of allowing the program to issue the LAT SYS$QIOW with IO$TTY_PORT | IO$M_LT_CONNECT.
You can use the CLOSE_DASSGN keyword to the /CREATE=(PERMANENT) qualifier to close the underlying TCP connection when the last channel assigned to the NTA device is dropped using SYS$DASSGN. The default is not to close the TCP connection.
You can have a startup file executed each time you invoke the Telnet client. The TELNET_STARTUP logical specifies a file that contains commands you want performed at the beginning of each TELNET session.
To set up and run a startup command file (see the below example):
1. Create a TELNET_STARTUP.COM file in your login directory.
2. In the file, include the TELNET command or commands you want executed each time you start the Telnet client.
3. Edit your LOGIN.COM file and define the TELNET_STARTUP logical name to point to the startup file. For example, add the following line to your login file:
$ DEFINE/PROCESS TELNET_STARTUP "SYS$LOGIN:TELNET_STARTUP.COM"
4. Rerun LOGIN and run TELNET.
Whenever you run TELNET, it first looks for the file to which the TELNET_STARTUP logical points. It then processes all the commands contained in that file until it processes the EXIT command or reaches the end of the file.
If the OPEN command appears in this file, TELNET establishes the connection, and all further input comes from the terminal. When you return to command mode, TELNET processes the rest of the commands in the startup file (if any).
If the EXIT command appears in the startup file, the Telnet client ignores all commands following the EXIT command and continues TELNET operations, leaving the user at the TELNET prompt.
Setting Up a Startup Command File:
$ CREATE TELNET_STARTUP.COM
SET TRANSLATION /SEND=CR
OPEN IRIS
OPEN HOMER
SHOW STATUS
Ctrl/Z
$ EDIT SYS$LOGIN:LOGIN.COM
$ DEFINE/PROCESS TELNET_STARTUP "SYS$LOGIN:TELNET_STARTUP.COM"
Ctrl/Z
$ @SYS$LOGIN:LOGIN
$ TELNET
TELNET>SET TRANSLATION /SEND=CR
%TCPWARE_TELNET-I-TRNSNEWLN, will translate CR to CRLF when sent
TELNET>OPEN IRIS
%TCPWARE_TELNET-I-TRYING, trying IRIS.plants.com,telnet
(192.168.1.93,23) ...
%TCPWARE_TELNET-I-ESCCHR, escape (attention) character is "^\"
(login procedure to IRIS)
(IRIS)$ Ctrl/\
TELNET>OPEN HOMER
%TCPWARE_TELNET-I-TRYING, trying HOMER.illiad.com,telnet
(192.168.1.90,23) ...
%TCPWARE_TELNET-I-ESCCHR, escape (attention) character is "^\"
(login procedure to HOMER)
(HOMER)$Ctrl/\
TELNET>SHOW STATUS
Connected sessions:
1. IRIS.plants.com, telnet (192.168.1.93,23).
-->2. HOMER.illiad.com, telnet (192.168.1.90,23).
"^\" is the escape (attention) character.
No characters are translated
to CRLF when received.
CR is translated to CRLF when sent.
TELNET>RESUME
(HOMER)$
This section shows a sample Telnet client session.
See the below example for the corresponding numbered steps. In this sample session, a user on IRIS:
1. Starts TELNET.
2. Enters the SHOW STATUS command.
3. Connects to TULIP.
4. Logs in and does some work. Enters the escape (attention) character to return to the TELNET prompt.
5. Changes the escape (attention) character and enters a SHOW STATUS command.
6. Enters the RESUME command to return to TULIP.
7. Logs out of TULIP.
8. Exits TELNET.
Sample Telnet Session:
(Iris) $ TELNET
TELNET>SHOW
STATUS
The Telnet client V6.1 Copyright (c) Process Software
No connection established.
Terminal type list: VT300, DEC-VT300, IBM-3278-2
"^\" is the escape (attention) character
TELNET>OPEN TULIP
%TCPWARE_TELNET-I-TRYING, trying tulip.example.com,telnet
(192.168.1.56,23)...
%TCPWARE_TELNET-I-ESCCHR, escape (attention) character is "^\"
SunOS 5.9 (tulip.example.com)(ttyp2)
login: root
Password: ********
Last login: Wed Feb 21 10:57:25 from 198.168.1.105
Sun Microsystems Inc. SunOS 5.9 Generic May 2021
tulip>ls
bin mnt notes test.c test_def.h
tulip>^\
TELNET>SET ESCAPE
"^A"
%TCPWARE_TELNET-I-ESCCHR, escape (attention) character is "^A"
TELNET>SHOW STATUS
The Telnet client V6.1 Copyright (c) Process Software
Connected session:
--1. tulip.example.com,telnet (192.168.1.56,23).
"^A" is the escape (attention) character
TELNET>RESUME
tulip>ls -A
. .forward bin test.c
.. .login mnt test_def.h
.cshrc .profile notes
TELNET>EXIT
(Iris)$
The following pages consist of command descriptions for the available Telnet client commands.
You interact with the Telnet client by typing commands at the TELNET> prompt. The Telnet client supports the following OpenVMS-style commands:
|
CLOSE |
SET [NO] BINARY |
SET [NO]LOCAL_FLOW |
|
DEFINE/KEY |
SET [NO]BRK |
SET LOG |
|
EXIT |
SET DEBUG |
SET PRINT |
|
FLUSH |
SET DELETE_ALLOWED |
SET TERMINAL_TYPE |
|
HELP |
SET [NO]EC |
SET TRANSLATION |
|
OPEN |
SET [NO]EL |
SET [NO]XDISPLOC |
|
RESUME |
SET [NO]ESCAPE |
SHOW OPTIONS |
|
SEND |
SET [NO]FLUSH |
SHOW STATUS |
|
SET [NO]AO |
SET [NO]FORWARD |
SHOW TRANSLATION |
|
SET [NO]AYT |
SET [NO]GA |
SPAWN |
|
SET [NO]BACKWARD |
SET [NO]IP |
|
Telnet command synonyms:
|
Synonym |
Equivalent |
Synonym |
Equivalent |
|
BYE or QUIT |
EXIT |
SET HOST |
OPEN |
|
CONNECT |
OPEN |
STATUS |
SHOW STATUS |
|
DISCONNECT |
CLOSE |
Z |
SPAWN |
|
ESCAPE |
SET ESCAPE |
|
|
Closes the current connection or the session specified by the session number. If you are not connected to a remote host, this command has no effect.
When you open a session using the alternate TELNET host format, the CLOSE command:
· Exits TELNET if the connection is the only session.
· Keeps you in TELNET with the other session(s) open if there is at least one other session.
CLOSE [session-number]
DISCONNECT [session-number]
session-number
Session number to close, based on the session number displayed by the SHOW STATUS command. If omitted, closes the current session. If there are any other connections open, the Telnet client resets the current session to the "next" one.
You can use the SHOW STATUS command to display a list of open connections. These examples start with HOMER as the current session. There are three telnet connections, as follows, with the current session being on HOMER:
1. BART.example.com, telnet
(192.168.1.92,23).
2. MARGE.example.com, telnet (192.168.1.91,23).
-->3. HOMER.example.com, telnet (192.168.1.90,23).
1. This example ends the session on MARGE. The current session is still HOMER. You can close any other session without affecting the status of the current session.
TELNET>CLOSE 2
%TELNET-S-LCLCLOSED, Local connection closed
-TELNET-I-SESSION, Session 02, host marge.example.com, port 23
%TELNET-I-CURRSESSION, current session is now 3, homer.example.com
2. This example ends the current session on HOMER and defaults to the session on BART. Because you are closing the current session, the Telnet client resets the current session to the “next” connected session.
TELNET>CLOSE
%TELNET-S-LCLCLOSED, Local connection closed
-TELNET-I-SESSION, Session 03, host homer.example.com, port 23
%TELNET-I-CURRSESSION, current session is now 1, bart.example.com
Associates an equivalence string and a set of attributes with a key on the terminal keyboard.
DEFINE/KEY key-name ["]equivalence-string["]
key-name
Name of the key to define. The below table lists key designations for three terminal types:
· On LK201 terminals, the numeric keypad, editing keypad (except the $ and ^ arrow keys), or function key row (except F1 through F5).
· On VT52 terminals, all definable keys are on the numeric keypad.
· On VT100-type terminals, you can also define the Ü and Þ keys. On VT200 terminals, the Ü, Þ, and F6 through F14 keys are for command line editing. Issue the DCL command SET TERMINAL/ NOLINE_EDITING to define these keys before you run the Telnet client. You can also press Ctrl+V to enable keys F7 through F14.
Key designations for three terminal types:
|
Key Name |
LK201 |
VT100-type |
VT52 |
|
PF1 |
PF1 |
PF1 |
[blue] |
|
PF2 |
PF2 |
PF2 |
[red] |
|
PF3 |
PF3 |
PF3 |
[gray] |
|
PF4 |
PF4 |
PF4 |
n/a |
|
KP0,...KP9 |
0,...,9 |
0,...,9 |
0,...,9 |
|
PERIOD |
. |
. |
. |
|
COMMA |
, |
, |
, |
|
MINUS |
- |
- |
- |
|
ENTER |
Enter |
ENTER |
ENTER |
|
LEFT |
‹ |
‹ |
‹ |
|
RIGHT |
fi |
fi |
fi |
|
Find (E1) |
Find |
|
|
|
Insert_Here (E2) |
Insert_Here |
|
|
|
Remove (E3) |
Remove |
|
|
|
Select (E4) |
Select |
|
|
|
Prev_Screen (E5) |
Prev_Screen |
|
|
|
Next_Screen (E6) |
Next_Screen |
|
|
|
HELP |
Help |
|
|
|
DO |
Do |
|
|
|
F6,...,F20 |
F6,...,F20 |
|
|
equivalence-string
String to substitute when you press the key. If the string contains spaces, enclose it in quotes.
/ECHO
/NOECHO
/ECHO (the default) displays the equivalence string on your screen after you press the key. /NOECHO disables this. Use /NOECHO with /TERMINATE only.
/IF_STATE=(state-name[,state-name,... ])
/NOIF_STATE
/IF_STATE specifies one or more state-names (alphanumeric strings separated
by commas) for the key definition to be in effect. You can omit the parentheses
if you specify only one state-name.
/NOIF_STATE is the default, where the current state
applies.
Establish states using the /SET_STATE qualifier (see below). If you specify several state-names, you can define a key to have the same function in all the specified states.
/LOCK_STATE
/NOLOCK_STATE
/LOCK_STATE specifies that the state set by the /SET_STATE qualifier remains in effect until explicitly changed. /NOLOCK_STATE is the default, where the state set by /SET_STATE is in effect only for the next definable key that you press or for the next read terminating character that you type.
You can only specify /LOCK_STATE with /SET_STATE.
/SET_STATE=state-name
/NOSET_STATE
/SET_STATE specifies the state-name (an alphanumeric string) to set when pressing the key. state-name is an alphanumeric string. The default is /NOSET_STATE, where the current locked state, if any, remains in effect.
/TERMINATE
/NOTERMINATE
Specifies whether to terminate (execute) the current
equivalence string when you press the key.
/NOTERMINATE (the default) lets you create key
definitions that insert text into command lines, at prompts, or into other text
you type.
Exits the Telnet client utility and returns to the DCL level. If there is an open connection or log file, the Telnet client closes it before exiting. Once you exit, all connections to remote hosts are disconnected.
EXIT
QUIT
BYE
Ctrl+Z
Discards all characters currently in the output stream from the server. Ignored if no connection is open.
|
Note: Unlike the flush character, the FLUSH command does not use the timing-mark option.
|
FLUSH
Obtains help on using the Telnet client utility. TELNET help uses the OpenVMS interactive help facility.
To exit the help facility, press the RETURN key until you return to the TELNET> prompt.
HELP [topic]
topic
Topic on which you want help. Optional.
Opens a connection to a remote host. You can open up to ten connections at any one time. The connection remains open until you log out of the remote host, or use the CLOSE or EXIT command at the TELNET> prompt.
|
Note: The same parameters and qualifiers apply to the TELNET command on the DCL level as apply to the OPEN command within TELNET.
|
OPEN [host [port]]
CONNECT [host [port]]
SET HOST [host [port]]
host
Name of the remote host to which you want to connect. The host must exist on the network.
Enter OPEN host to open a remote connection and start the login sequence, if any. If you omit host and a connection is open, the Telnet client resumes the session to that host.
port
Nonstandard service name or number of the remote port to which you want to connect. The default is TELNET or 23 (for the TELNET server). Use only to connect to a nonstandard server. As an alternative, use the /PORT qualifier (DO NOT use both in the same command).
/CREATE [=(PERMANENT, BROKE_TIMO=seconds,
CLOSE_DASSGN,
INTERVAL=seconds, [NO]KEEPALIVE, NOOPCOM, NOTCONNECTED_OK,
RETRIES=number), SHUT_ABORT) ]
Associates the local client end of the TELNET connection to
an NTA device. Lets you use the connection for terminal activities such as
printing or running applications. Supports /RAW,
/LOGICAL, and /TIMEOUT.
The /CREATE keyword creates the NTA device as pre-allocated so that it is not deleted when exiting TELNET. However, deallocating the device deletes it automatically when there are no process channels assigned to it (the reference count drops to zero). The PERMANENT keyword causes the client NTA device NOT to be deleted automatically when there are no process channels assigned to it, thus creating a permanent connection similar to an application LTA device for LAT. As with LAT, if the TELNET connection is broken, the Telnet client device tries to reconnect to the specified host and port. Further parameters control the broken connection and reconnection algorithms:
|
BROKE_TIMO=seconds |
Used to determine when a connection is broken. (Note that the OPEN /TIMEOUT qualifier value is used in establishing the connection, and another timeout of eight minutes is used when sending data.) If omitted, the /TIMEOUT value is used. Also applies to non-permanent NTA devices (when using OPEN/CREATE without the PERMANENT keyword). |
|
CLOSE_DASSGN |
Specifies that when the last channel is de-assigned from the NTA device, the underlying TCP connection is closed. The default is NOT to close the TCP connection. Use with the PERMANENT keyword only. |
|
INTERVAL=seconds |
Connection retry interval, the minimum time to wait until another connect is attempted. The default is 120 seconds (two minutes). Use with the PERMANENT keyword only. |
|
KEEPALIVE or NOKEEPALIVE |
Controls whether keep-alive segments are sent to the remote port. The default is KEEPALIVE. Also applies to non-permanent NTA devices (when using OPEN/CREATE without the PERMANENT keyword). |
|
NOOPCOM |
Specifies that no OPCOM messages are used when a permanent NTA device fails to reconnect or reconnects after an initial failure. OPCOM messages are sent by default. |
|
NOTCONNECTED_OK |
A permanent NTA device is created even if a TCP connection cannot initially be set up. |
|
RETRIES=number |
Number of times to try to reconnect after a connection breaks; the default is -1, handled as an unsigned number and thus actually 4,294,967,295, which is, in effect, infinite. Use with the PERMANENT keyword only. |
|
SHUT_ABORT |
Specifies that a permanent NTA device will do extra TCP device clean up after the underlying TCP connection is shutdown. This is similar to doing NETCU> KILL CONNECTION for a closed TCP device. |
Setting RETRIES to 0 means that when either end closes the TCP connection, no reconnects automatically occur. However, a reconnection attempt is made without delay when a write operation to the permanent NTA device occurs. If RETRIES is not set to 0, automatic retries occur when the connection closes. If all those retries fail, and a write is done later to the NTA device, then the specified number of retries is attempted.
Here is a typical command to create a TELNET connection to a printer (note the use of /RAW to avoid sending TELNET options negotiation data):
$ TELNET /RAW /CREATE=(PERM, RETRIES=0, CLOSE) host port
After TELNET creates a permanent NTA device with an underlying TCP connection, the NTA device's reference count drops to 0; thus, the TCP connection is closed. When a write operation occurs to the NTA device, an attempt is made to re-establish the TCP connection. Meanwhile the data being written is held so that it can be sent when reconnected. If all reconnects fail, the write data is dropped. When the application de-assigns its channels to the NTA device, its TCP connection is again closed.
To specify that the permanent NT device should be treated as a local terminal rather than a remote terminal (to allow for spooling of the device), add the LOCAL keyword to the TELNET /CREATE qualifier:
$ TELNET /CREATE=(PERM,LOCAL)
/LOGICAL=name [/TABLE=table][/MODE=mode]
Logical name defined for the allocated NTA device. Use only with the /CREATE qualifier. The table values are PROCESS (the default), JOB, GROUP, or SYSTEM. The mode values are SUPERVISOR (the default) or EXECUTIVE.
/PORT=port
Nonstandard service name or number of the remote port to which you want to connect. The default is 23 (for the TELNET server). Use only to connect to a nonstandard server. Alternatively, use the port command parameter (DO NOT use both in the same command).
/RAW
Specifies a raw, binary connection that does not adhere to the TELNET protocol. Use only with the /CREATE qualifier.
/TIMEOUT=seconds
Timeout time for establishing the TELNET control connection. If not specified, the default value of 120 seconds (2 minutes) applies. The minimum allowable value is 20.
1. This example creates a permanent NTA device for the connection to MARGE port 7 for the user application. In case the connection goes down, it is set up so that automatic reconnection retries occur every 10 seconds for a total of 10 retries.
TELNET>OPEN /LOGICAL=MY_PORT -
_TELNET>/CREATE=(PERMANENT,INTERVAL=10,RETRIES=10)
MARGE 7
%TCPWARE_TELNET-I-CREATED,
_NTA2: created
$ @MY_APPLICATION MY_PORT
2. This example displays the results of incorrectly using the port parameter value (telnet) together with the /PORT qualifier and value in a single command:
TELNET>OPEN DAISY TELNET /PORT=23
%TCPWARE_TELNET-W-CONFLICT illegal combination of command elements - check documentation
Resumes the current connection if you do not specify a session number. If you specify a session number, resumes the connection associated with the session number, as displayed by the SHOW STATUS (or STATUS) command.
RESUME [session-number]
session-number
Session number to resume, based on the session number the SHOW STATUS command displays. If omitted, resumes the current connection.
1. This example resumes the session on BART. The Telnet client does not display a message if the user resumes the current session:
TELNET>SHOW STATUS
Connected session:
-->1. BART.example.com, telnet (192.168.1.92,23).
TELNET>RESUME
(bart)$
2. This example resumes session 2 on MARGE:
TELNET>STATUS
Connected sessions:
1. BART.example.com, telnet (192.166.1.92,23).
2. MARGE.example.com, telnet (192.166.1.91,23).
-->3. HOMER.example.com, telnet (192.162.1.90,23).
TELNET>RESUME 2
%TCPWARE_TELNET-I-RESUME,
resuming session 2, MARGE.example.com
(marge)$
Sends TELNET control functions or option negotiations to a remote host.
SEND {control-function | {command option}}
control-function
The below table lists the available TELNET control functions. Send a control function to gain access to functions of the remote host that are not available from the keyboard.
|
Control Function |
Definition |
|
AO |
Abort Output |
|
AYT |
Are You There |
|
BACKWARD |
Sends the current Telnet client Backward character |
|
BRK |
Break |
|
EC |
Erase Character |
|
EL |
Erase Line |
|
ESCAPE |
Sends the current The Telnet client Escape character |
|
FORWARD |
Sends the current The Telnet client Forward character |
|
GA |
Go-Ahead |
|
IP |
Interrupt Process |
|
NOIP |
Do Not Interrupt Process |
|
SYNCH |
SYNCH signal |
One of the following TELNET protocol commands used in options negotiation:
|
DO |
WILL |
DONT |
WONT |
Negotiated TELNET option. The Telnet client supports the following option keywords:
|
ECHO |
for the ECHO option
SEND WILL ECHO is an invalid command. The Telnet client does not allow the user to send this option negotiation to the TELNET server. |
|
BINARY, or TRANSMIT_BINARY |
for the TRANSMIT-BINARY option |
|
SGA, or SUPPRESS_GO_AHEAD |
for the SUPPRESS-GO-AHEAD option |
Defines, changes, or disables the "abort output" (AO) character. During a TELNET session, if you enter the defined AO character, the Telnet client sends the TELNET AO control function to the server instead of the actual character.
SET AO char
SET NOAO
char
When entered, this character sends the TELNET AO control function to the server. You can specify this character in either of the following formats:
· Numeric: ASCII value of the character
· String: Character string enclosed in quotes. Specify control characters by typing a caret (^) before the character.
There is no default AO character. Define the initial AO character using the TCPWARE_TELNET_AO logical name (in the process, job, group, or system logical name tables). To define the logical, use one of the following formats:
· $ DEFINE/PROCESS TCPWARE_TELNET_AO 15
· $ DEFINE/PROCESS TCPWARE_TELNET_AO """^O"""
Both commands set the AO character to Ctrl+O (ASCII 15). They are equivalent.
/FLUSH
/NOFLUSH
If you specify /FLUSH, the Telnet client discards all characters currently in the output stream from the server when sending the AO control function. The Telnet client uses the TELNET timing-mark option to accomplish this (the server does not have to support this option for this feature to work). If you specify /NOFLUSH, the Telnet client sends only the AO control function. If you omit both, the previous setting remains. The initial default is /FLUSH.
If there is no response to the timing-mark option, the Telnet client may continue to discard output from the server. Use the FLUSH command to resume normal operation.
/SYNCH
/NOSYNCH
Sends the AO command followed by the SYNCH signal.
1. Each of these equivalent commands sets the AO character to Ctrl+O (ASCII 15):
TELNET>SET AO "^O"
TELNET>SET AO 15
2. This example removes the previous character definition, if any, for the AO control function:
TELNET> SET NOAO
Defines, changes, or disables the "are you there" (AYT) character. If you enter the defined AYT character during a TELNET session, the Telnet client sends the TELNET AYT control function to the server instead of the actual character.
SET AYT char
SET NOAYT
char
When entered, this character sends the TELNET AYT control function to the server. You can specify this character in either of the following formats:
· Numeric: ASCII value of the character
· String: Character string enclosed in quotes. Specify control characters by typing a caret (^) before the character.
There is no default AYT character. Define the initial AYT character using the TCPWARE_TELNET_AYT logical name (in the process, job, group, or system logical name tables). To define the logical, use one of the following formats:
· $ DEFINE/PROCESS TCPWARE_TELNET_AYT 7
· $ DEFINE/PROCESS TCPWARE_TELNET_AYT """^G"""
Both commands set the AYT character to Ctrl+G (ASCII 7). They are equivalent.
/SYNCH
Sends the AYT command followed by the SYNCH signal.
1. Each of these equivalent commands sets the AYT character to Ctrl+G (ASCII 7):
TELNET>SET AYT "^G"
TELNET>SET AYT 7
2. This example removes the previous character definition, if any, for the AYT control function:
TELNET>SET NOAYT
Defines, changes, or disables the "backward (one session)" (BACKWARD) character. If you enter the BACKWARD character during a TELNET session, the "previous" numbered session becomes active. The previous numbered session is the session with the next lowest session number than the current session.
If the current session already has the lowest session number, the session with the highest session number becomes active. If there is only one active session available, that session remains active. In this case SET BACKWARD has no effect.
SET BACKWARD char
SET NOBACKWARD
char
When entered, this character causes the "previous" numbered session to become active. You can specify this character in either of the following formats:
· Numeric: ASCII value of the character
· String: Character string enclosed in quotes. Specify control characters by typing a caret (^) before the character.
There is no default BACKWARD character. Define the initial BACKWARD character using the TCPWARE_TELNET_BACKWARD logical name (in the process, job, group, or system logical name tables). To define the logical, use one of the following formats:
· $ DEFINE/PROCESS TCPWARE_TELNET_BACKWARD 2
· $ DEFINE/PROCESS TCPWARE_TELNET_BACKWARD """^B"""
Both commands set the BACKWARD character to Ctrl+B (ASCII 2). They are equivalent.
1. Each of these equivalent commands sets the BACKWARD character to Ctrl+B (ASCII 2):
TELNET>SET BACKWARD "^B"
TELNET>SET BACKWARD 2
2. This example removes the previous character definition, if any, for the BACKWARD control function:
TELNET>SET NOBACKWARD
Initiates negotiations to enable the TRANSMIT BINARY option for the client and server. This command:
· Pertains only to the current session.
· Automatically resumes the current session.
Use the SET NOBINARY command to initiate negotiations to disable the TRANSMIT BINARY option for the client and server.
SET BINARY
SET NOBINARY
Defines, changes, or disables the break (BRK) character. If you define the BRK character during a TELNET session, the Telnet client sends the TELNET BRK control function to the server instead of the actual character.
SET BRK char
SET NOBRK
char
When entered, this character sends the TELNET break control function to the server. Specified in either of the following formats:
· Numeric: ASCII value of the character
· String: Character string enclosed in quotes. Specify control characters by typing a caret (^) before the character.
There is no default BRK character. Define the initial BRK character using the TCPWARE_TELNET_BRK logical name (in the process, job, group, or system logical name tables). To define the logical, use one of the following formats:
· $ DEFINE/PROCESS TCPWARE_TELNET_BRK 29
· $ DEFINE/PROCESS TCPWARE_TELNET_BRK """^]"""
Both commands set the break character to Ctrl/] (ASCII 29). They are equivalent.
/FLUSH
/NOFLUSH
If you specify /FLUSH, the Telnet client discards all characters currently in the output stream from the server when sending the BRK function. The Telnet client uses the TELNET timing-mark option to accomplish this (the server does not have to support this option for this feature to work).
If you specify /NOFLUSH, the Telnet client sends only the BRK function. If you omit both, the previous setting remains. The initial default is /FLUSH.
|
Note: If a server fails to respond properly to the timing-mark option, the Telnet client may continue to discard output from the server. In this case, use the FLUSH command to resume normal operation.
|
1. Each of these equivalent commands sets the break character to Ctrl+] (ASCII 29):
TELNET>SET BRK "^]"
TELNET>SET BRK 29
2. This example removes the previous character definition, if any, for the break control function:
TELNET>SET NOBRK
Enables or disables the display of debugging information.
SET DEBUG /CLASS=[(]keyword[,…)]
/CLASS[=keyword]
SET DEBUG requires the /CLASS qualifier. The optional keyword specifies the classes of debugging information to enable or disable. Use parentheses for multiple keywords separated by commas. The below table lists the supported keywords.
|
Keyword |
Description |
|
ALL |
Enables the display of all classes. |
|
OPTIONS |
Enables the display of options negotiation information. The Telnet client displays messages when it sends or receives TELNET options. |
|
NONE |
Disables the display of all classes. |
The initial setting is NONE.
SET DEBUG alone, or SET DEBUG /CLASS without the keyword, shows the current debug classes.
1. This example enables the display of options negotiation information:
TELNET>SET DEBUG/CLASS=OPTIONS
Allows deletion of an NTA device originally set up as permanent. The deletion occurs when there are no process channels assigned to the device.
See the OPEN /CREATE command for details on creating permanent NTA devices.
SET DELETE_ALLOWED nta-device
nta-device
NTA device set up using OPEN /CREATE=(PERMANENT…).
This example allows the NTA33: device to be deleted when no channels are assigned to it:
TELNET>SET DELETE NTA33:
Defines, changes, or disables the "erase character" (EC) character. If you enter the defined EC character during a TELNET session, the Telnet client sends the TELNET EC control function to the server instead of the actual character.
SET EC char
SET [NO]EC
char
When entered, this character sends the TELNET EC control function to the server. You can specify this character in either of the following formats:
· Numeric: ASCII value of the character
· String: Character string enclosed in quotes. Specify control characters by typing a caret (^) before the character.
There is no default EC character. Define the initial EC character using the TCPWARE_TELNET_EC logical name (in the process, job, group, or system logical name tables). To define the logical, use one of the following formats:
· $ DEFINE/PROCESS TCPWARE_TELNET_EC 4
· $ DEFINE/PROCESS TCPWARE_TELNET_EC """^D"""
Both commands set the EC character to Ctrl/D (ASCII 4). They are equivalent.
1. Each of these equivalent commands sets the EC character to Ctrl+D (ASCII 4):
TELNET>SET EC “^D”
TELNET>SET
EC 4
2. This example removes the previous character definition, if any, for the EC control function:
TELNET>SET NOEC
Defines, changes, or disables the "erase line" (EL) character. If you enter the defined EL character during a TELNET session, The Telnet client sends the TELNET EL control function to the server instead of the actual character.
SET EL char
SET NOEL
char
When entered, this character sends the TELNET EL control function to the server. You can specify this character in either of the following formats:
· Numeric: ASCII value of the character
· String: Character string enclosed in quotes. Specify control characters by typing a caret (^) before the character.
There is no default EL character. Define the initial EL character using the TCPWARE_TELNET_EL logical name (in the process, job, group, or system logical name tables). To define the logical, use one of the following formats:
· $ DEFINE/PROCESS TCPWARE_TELNET_EL 21
· $ DEFINE/PROCESS TCPWARE_TELNET_EL """^U"""
Both commands set the EL character to Ctrl/U (ASCII 21). They are equivalent.
1. Each of these equivalent commands sets the EL character to Ctrl+U (ASCII 21):
TELNET>SET EL "^U"
TELNET>SET
EL 21
2. This example removes the previous character definition, if any, for the EL control function:
TELNET>SET NOEL
SET ESCAPE changes the escape (attention) character. This command allows you to change the character to a key that is more convenient. The default escape character is Ctrl+\. You may want to change the escape character if the remote host uses that character to perform some function or if your terminal cannot generate the character.
SET NOESCAPE disables the escape (attention) character.
SET ESCAPE char
SET NOESCAPE
ESCAPE = SET ESCAPE
char
You can specify this character in either of the following formats:
· Numeric: ASCII value of the character
· String: Character string enclosed in quotes. Specify control characters by typing a caret (^) before the character.
You can redefine the default escape (attention) character by defining the logical TCPWARE_TELNET_ESCAPE (in the process, job, group, or system logical name tables). The logical value has the same syntax as char. To define it, use one of the following formats:
· $ DEFINE/PROCESS TCPWARE_TELNET_ESCAPE 24
· $ DEFINE/PROCESS TCPWARE_TELNET_ESCAPE """^X"""
Both commands set the escape character to ASCII code 24 (Ctrl+X). They are equivalent.
· $ DEFINE/SYSTEM/EXEC TCPWARE_TELNET_ESCAPE -1
The -1 value disables the escape (attention) character.
1. Each of these equivalent commands sets the escape character to Ctrl+X (ASCII 24):
TELNET>SET ESCAPE "^X"
TELNET>SET ESCAPE 24
2. This example sets the escape character to right brace (}):
TELNET>SET ESCAPE "}"
3. This example removes the previous escape (attention) character definition, if any:
TELNET>SET NOESCAPE
Defines, changes, or disables the flush character.
If you enter the defined flush character during a TELNET session, the Telnet client discards all characters currently in the output stream from the server. The Telnet client uses the TELNET timing-mark option to accomplish this (a TELNET server need not support this option for this feature to work).
|
Note: If a server fails to respond properly to the timing-mark option, the Telnet client may continue to discard all output from the server. In this case, use the FLUSH command to resume normal operation.
|
SET FLUSH char
SET NOFLUSH
char
When entered, this character discards all characters currently in the output stream from the server. You can specify this character in either of the following formats:
· Numeric: ASCII value of the character
· String: Character string enclosed in quotes. Specify control characters by typing a caret (^) before the character.
There is no default flush character. Define the initial flush character using the TCPWARE_TELNET_FLUSH logical name (in the process, job, group, or system logical name tables). To define the logical, use one of the following formats:
· $ DEFINE/PROCESS TCPWARE_TELNET_FLUSH 15
· $ DEFINE/PROCESS TCPWARE_TELNET_FLUSH """^O"""
Both commands set the flush character to Ctrl+O (ASCII 15). They are equivalent.
1. Each of these equivalent commands sets the flush character to Ctrl+O (ASCII 15):
TELNET>SET FLUSH "^O"
TELNET>SET FLUSH 15
2. Removes the previous character definition, if any, for the flush feature.
TELNET>SET NOFLUSH
Defines, changes, or disables the "forward [one session]" (FORWARD) character. If you enter the defined FORWARD character during a TELNET session, the "next" numbered session becomes active. The next numbered session is the session with the next highest session number than the current session.
If the current session already has the highest session number, the session with the lowest session number becomes active. If there is only one active session available, that session remains active. In this case SET FORWARD has no effect.
SET FORWARD char
SET NOFORWARD
char
When entered, this character causes the "next" numbered session to become active. You can specify this character in either of the following formats:
· Numeric: ASCII value of the character
· String: Character string enclosed in quotes. Specify control characters by typing a caret (^) before the character.
There is no default FORWARD character. Define the initial FORWARD character using the TCPWARE_TELNET_FORWARD logical name (in the process, job, group, or system logical name tables). This logical value has the same syntax as char. To define the logical, use one of the following formats:
· $ DEFINE/PROCESS TCPWARE_TELNET_FORWARD 1
· $ DEFINE/PROCESS TCPWARE_TELNET_FORWARD """^A"""
Both commands set the FORWARD character to Ctrl+A (ASCII 1). They are equivalent.
1. Each of these equivalent commands sets the FORWARD character to Ctrl+A (ASCII 1):
TELNET>SET FORWARD "^A"
TELNET>SET FORWARD 1
2. This example removes the previous character definition, if any, for the FORWARD control function:
TELNET>SET NOFORWARD
Defines, changes, or disables the "go-ahead" (GA) character. If you enter the defined GA character during a TELNET session, the Telnet client sends the TELNET GA control function to the server instead of the actual character.
SET GA char
SET NOGA
char
When entered, this character sends the TELNET GA control function to the server. You can specify this character in either of the following formats:
· Numeric: ASCII value of the character
· String: Character string enclosed in quotes. Specify control characters by typing a caret (^) before the character.
There is no default GA character. Define the initial GA character using the TCPWARE_TELNET_GA logical name (in the process, job, group, or system logical name tables). To define the logical, use one of the following formats:
· $ DEFINE/PROCESS TCPWARE_TELNET_GA 9
· $ DEFINE/PROCESS TCPWARE_TELNET_GA """^I"""
Both commands set the GA character to Ctrl+A (ASCII 9). They are equivalent.
1. Each of these equivalent commands sets the GA character to Ctrl+A (ASCII 9):
TELNET>SET GA "^I"
TELNET>SET GA 9
2. This example removes the previous character definition, if any, for the GA control function:
TELNET>SET NOGA
Defines, changes, or disables the "interrupt process" (IP) character. If you enter the defined IP character during a TELNET session, the Telnet client sends the TELNET IP control function to the server instead of the actual character.
SET IP char
SET NOIP
char
When entered, this character sends the TELNET IP control function to the server. You can specify this character in either of the following formats:
· Numeric: ASCII value of the character
· String: Character string enclosed in quotes. Specify control characters by typing a caret (^) before the character.
There is no default IP character. Define the initial IP character using the TCPWARE_TELNET_IP logical name (in the process, job, group, or system logical name tables). To define the logical, use one of the following formats:
· $ DEFINE/PROCESS TCPWARE_TELNET_IP 25
· $ DEFINE/PROCESS TCPWARE_TELNET_IP """^Y"""
Both commands set the IP character to Ctrl+Y (ASCII 25). They are equivalent.
/FLUSH
/NOFLUSH
With /FLUSH, the Telnet client discards all characters currently in the server's output stream when sending the IP control function. It uses the TELNET timing-mark option (the server does not have to support this option for this feature to work). With /NOFLUSH, the Telnet client sends only the IP control function. If you omit both, the previous setting remains. The initial default is /FLUSH.
If a server fails to respond properly to the timing-mark option, the Telnet client can continue to discard all output from the server. If so, use FLUSH to resume normal operation.
/SYNCH
Sends the IP command followed by the SYNCH signal.
1. Each of these equivalent commands sets the IP character to Ctrl+Y (ASCII 25):
TELNET>SET IP "^Y"
TELNET>SET IP 25
2. This example removes the previous character definition, if any, for the IP
control function.
TELNET>SET NOIP
Controls the handling of the XON/XOFF characters (Ctrl+S and Ctrl+Q) when connected to a remote system. Ctrl+S stops transmission and Ctrl+Q resumes TELNET transmission. Under normal conditions, the terminal driver processes Ctrl+S and Ctrl+Q locally and does not send them to the remote TELNET server.
The Telnet client supports RFC 1372 (Telnet Remote Flow Control Option), which lets the remote server tell the client when to enable and disable local flow control. These commands are not related to that option, but rather let the user control the local flow control setting if the remote server does NOT support the Remote Flow Control Option.
Use SET NOLOCAL_FLOW_CONTROL to pass the Ctrl+S and Ctrl+Q characters to the remote TELNET server and NOT process them locally.
The default flow control setting depends on the TT$V_TTSYNC value for the terminal. You can set "TTSync" mode (local flow control) outside of TELNET by using the DCL SET TERMINAL /TTSYNC command, or set "No TTSync" mode (server flow control) by using the DCL SET TERMINAL /NOTTSYNC command; some full-screen editors also set these modes. However, if you are inside TELNET, SET NOLOCAL_FLOW_CONTROL can force the terminal into "No TTSync" mode for a particular connection.
SET LOCAL_FLOW_CONTROL
SET NOLOCAL_FLOW_CONTROL
TELNET>SET NOLOCAL
TELNET>SHOW
STATUS
Telnet client V6.1 Copyright (c) Process Software
Connected session: -->1. beans.example.edu, telnet (192.168.0.50)
Terminal type: VT300
Local flow control: OFF
"^D" is the escape (attention) character.
Opens or closes a log file. The Telnet client uses a log file to save the output from a remote host. While connected to a remote host, the Telnet client also puts all output the remote host sends your terminal into the log file.
SET LOG logs output from every connected session. If multiple connections exist, there is no way to specify that you want to log only output from a specified session to the log file.
SET LOG [file]
Opens the local file file and begins logging. To close a log file (and stop logging), enter SET LOG with no file specification.
file
OpenVMS file specification of the file that logs the remote host's output. If omitted, the Telnet client closes the present log file (if there is one).
/DATA
/NODATA
/DATA logs all data sent to the specified file (the default). /NODATA disables this.
/OPTIONS
/NOOPTIONS
/OPTIONS prints option negotiations to the specified log file, in addition to performing normal logging. /NOOPTIONS (the default) disables options printing.
1. This example opens the file TEXT.LOG and enables logging:
TELNET>SET LOG TEXT.LOG
2. This example closes a log file and stops logging:
TELNET>SET LOG
3. This example opens the file TEXT.LOG, enables normal logging, and prints options negotiations to the TEXT.LOG file:
TELNET>SET LOG TEXT.LOG /OPTIONS
4. This example opens the file TEXT.LOG and prints only option negotiations (and no data) to the TEXT.LOG file:
TELNET>SET LOG TEXT.LOG /OPTIONS /NODATA
Requests the server to support a specific terminal type or types if negotiating the terminal type option.
Normally, you do not need to use this command. The telnet client uses the following default list of supported terminal types: VT52, VT55, VT61, VT62, VT100, VT102, VT125, VT131, VT132, VT200, VT220, VT240, VT300, VT320, VT340, and IBM-3278-model-number.
If you specify an IBM-3278 terminal type, make sure your local terminal supports the screen size associated with the specified model number. If your terminal does not support the screen size, the data will not display properly.
Use the SHOW STATUS or SHOW OPTIONS commands to show the current terminal type used.
The TCPWARE_TELNET_TERMINAL_TYPE logical performs the same function as the SET TERMINAL_TYPE command. This logical requires the following syntax:
$ DEFINE/SYSTEM/EXEC TCPWARE_TELNET_TERMINAL_TYPE "type"
SET TERMINAL_TYPE type[,type,...]
type
A valid terminal type. The Telnet client requests the server to support these types in the specified order.
1. This example requests the server to support the VT300 and VT100 terminal types, in that order:
TELNET>SET TERMINAL_TYPE VT300, VT100
2. This example requests the server to support the IBM-3278-3 terminal type. If possible, the Telnet client resizes the local window to accommodate a 32 x 80 screen size for model 3.
TELNET>SET TERMINAL_TYPE IBM-3278-3
Sets the carriage return/line feed (CR/LF) character translation.
SET TRANSLATION
/RECEIVE=keyword
Specifies the mapping for characters received from the server before they become output. See the below table for the keywords and their meaning. The default is /RECEIVE=NONE.
/SEND=keyword
Specifies the mapping for characters entered at the keyboard before the Telnet client sends them to the server. See the below table for the keywords and their meaning. The default is /SEND=CR.
|
Keyword |
Translation |
|
CR |
The Telnet client translates the carriage return character to a CR/LF sequence |
|
LF |
The Telnet client translates the line feed character to a CR/LF sequence |
|
NONE |
The Telnet client does not translate characters to the CR/LF sequence |
Enables or disables setting your current X display location on the remote end, when communicating with a remote TELNET server that also supports this option. Client TELNET checks whether the logical DECW$DISPLAY is defined. If it is, and if the remote server asks for the X display location, the X display server address is transmitted to the remote system.
Use SET NOXDISPLOC before making a connection to disable sending the X display location.
SET XDISPLOC
SET NOXDISPLOC
TELNET>SET NOXDISPLOC
TELNET>OPEN
ALPHA
$ SHOW DISPLAY
Error opening DECW$DISPLAY as input
No such device available
ALPHA>
Displays information about the options in effect.
Options modify the way TELNET handles your terminal over the network. When you first establish a connection, both hosts negotiate for the options to use based on the options that each host supports. You can also use the SEND command to change options.
SHOW OPTIONS
TELNET>SHOW OPTIONS
Current TELNET options status:
Remote ECHO
No remote TRANSMIT-BINARY (normal ASCII)
No local TRANSMIT-BINARY (normal ASCII)
Remote SUPPRESS-GO-AHEADS
Local SUPPRESS-GO-AHEADS
No remote END-OF-RECORD
No local END-OF-RECORD
Local TERMINAL-TYPE: VT300
Local FLOW-CONTROL: ON
Local WINDOW-SIZE: 80x35
Local X-DISPLAY-LOCATION: 192.168.5.195:0.0
Displays information about all open TELNET connections and your current TELNET session.
The screen displays the following information:
· Session number, name and internet address of each remote host if a connection is open. An arrow (-->) indicates the current session.
· The list of supported terminal types if no remote connection is open.
· The terminal type used, if a remote connection is open and the Telnet client negotiated for the terminal type.
· Whether local flow control is ON or OFF.
· Name of the log file if one is open.
· Name of the host character set.
· Name of the terminal character set.
· The current "abort output" (AO), "are you there" (AYT), backward, break (BRK), "erase character" (EC), "erase line" (EL), escape, forward, flush, "interrupt process" (IP), and "go-ahead" (GA) characters (if defined).
SHOW STATUS
STATUS
TELNET> SHOW STATUS
Telnet client V6.1 Copyright
(c) Process Software
Connected sessions:
1. bart.example.com, telnet (192.168.1.92,23).
-->2. marge.example.com, telnet (192.168.1.91,23).
"^\" is the escape (attention) character
Terminal type: IBM-3278-2
Local flow control: ON
Host Character Set: CANADIAN
Terminal Character Set: LATIN1
"^C" is the escape (attention) character.
Displays the current translation settings made using SET TRANSLATION. Both the received and sent translations appear.
SHOW TRANSLATION
TELNET> SHOW TRANSLATION
No characters are translated to CRLF when received.
CR is translated to CRLF when sent.
Executes DCL commands.
|
Note: You cannot SPAWN with CAPTIVE accounts.
|
SPAWN [command-line]
Z[command-line]
command-line
DCL command line that you want executed. If omitted, the Telnet client spawns an interactive subprocess. To return to TELNET from an interactive subprocess, logout of that subprocess.
1. This example displays the time on your local host without leaving the TELNET utility:
TELNET>SPAWN SHOW TIME
3-Nov-2021 14:02:48
2. This example initiates DCL command mode and returns the DCL prompt:
TELNET>SPAWN
$ SHOW TIME
3-Nov-2021 14:02:51
$ LOGOUT
Process SMITH_1 logged out at 3-Nov-2021 14:02:54.34
TELNET>
To exit the DCL command mode and return to TELNET, enter the LOGOUT command at the DCL prompt.