HP OpenVMS Systems Documentation
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Compaq TCP/IP Services for OpenVMS
User's Guide
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DELETE_SESSION

Deletes an outbound TELNET pseudodevice (network terminal) created by the CREATE_SESSION command. If the device was not created with the CREATE_SESSION command, the command returns an error.

DCL Format

DELETE_SESSION unit

Parameters

unit

Required.

The decimal number specifying the unit number of the pseudodevice (TNx) to be deleted.

Example


TELNET> DELETE_SESSION 2

Deletes the network terminal known as TNA2.

DISCONNECT

Terminates the current remote connection.

If you terminate a session with a remote OpenVMS host, the connection is closed by your local host. However, the process on the remote host is still running. To terminate it, enter a LOGOUT command.

DCL Format

DISCONNECT

UNIX Format

close

ENABLE (DISABLE) AUTOFLUSH

Enables or disables the automatic flushing of output when you send the interrupt character.
  • Enabled --- The data in the data buffer remains visible until the buffer is empty.
  • Disabled --- The data buffer is emptied and the display is terminated. This provides fast system response to the interrupt character.

Default: ENABLE AUTOFLUSH

DCL Format

ENABLE AUTOFLUSH

DISABLE AUTOFLUSH

UNIX Format

toggle autoflush

ENABLE (DISABLE) AUTOSYNCH

Enables or disables the sending of the synchronization and interrupt characters in urgent mode.
  • Enabled --- The local host sends an interrupt character in urgent mode, and the remote host immediately processes it.
  • Disabled --- TELNET sends the interrupt character in sequence with the other characters in the stream, and the remote host processes this character in the sequence received.

Default: DISABLE AUTOSYNCH.

DCL Format

ENABLE AUTOSYNCH

DISABLE AUTOSYNCH

UNIX Format

toggle autosynch

ENABLE (DISABLE) BINARY

Enables or disables the transmission of data in binary mode.
  • Enabled --- The EOL (end-of-line) character is not mapped to Return LF (the carriage return/line feed combination).
    Use ENABLE BINARY when the remote host expects each line to end with a carriage return/line feed combination.
    Binary mode provides interaction when the remote host:
    • Expects special characters.
    • Does not support automatic negotiation of the TELNET binary option.
  • Disabled --- EOL is sent as Return LF (the carriage return/line feed combination).

Default: DISABLE BINARY

DCL Format

ENABLE BINARY

DISABLE BINARY

UNIX Format

toggle binary

ENABLE (DISABLE) CRLF

Enables or disables the sending of carriage returns as Return LF (the carriage return/line feed combination) at the end of each line.
  • Use ENABLE CRLF if the remote host expects Return LF at the end of each line.
  • Use DISABLE CRLF if the remote host interprets Return as Return LF, which is CR mode.

Default: ENABLE CRLF

DCL Format

ENABLE CRLF

DISABLE CRLF

UNIX Format

toggle crlf

ENABLE (DISABLE) CRMOD

Enables or disables the mapping of received carriage returns. With this mapping, the remote host sends each line with Return LF (the carriage return/line feed combination) at the end of each line.
  • Use ENABLE CRMOD if your terminal expects each line to end with Return LF.
  • Use DISABLE CRMOD if your terminal expects Return null at the end of each line.

Default: DISABLE CRMOD

DCL Format

ENABLE CRMOD

DISABLE CRMOD

UNIX Format

toggle crmod

ENABLE (DISABLE) DEBUG

Enables or disables the display of data in hexadecimal.
  • Enabled --- Data is displayed in both hexadecimal and readable text.
  • Disabled --- Data is displayed in readable text.

Default: DISABLE DEBUG

DCL Format

ENABLE DEBUG

DISABLE DEBUG

UNIX Format

toggle netdata

Example


% [Ctrl/Z]  (characters not echoed)
TELNET> enable debug [Return]
TELNET> display [Return]
   .
   .
   .
Will print network data flow in hexadecimal
.
.
.
TELNET>)resume [Return]
SEND [   0] D A
RCVD [   0] D A
RCVD [   0] 746E7069782E6C6B672E6465632E636F6D3E20
% ls [Return]
SEND [   0] 6C
RCVD [   0] 6C l
SEND [   0] 73
RCVD [   0] 73 s
SEND [   0] D A
RCVD [   0] D A
RCVD [   0] 62696E20202020202020...
RCVD [  32] 7074 D A
french.estud.oiseau     russian.estud.ptitsa     fences
typescript     verio
%

Escapes from a session with a UNIX host, enables debug mode, resumes the session, and asks for a list of files in the working directory. Both hexadecimal data and readable data are displayed.

ENABLE (DISABLE) LOCAL_CHARS

Enables or disables the translation of the following terminal control characters in to TELNET protocol sequences:
  • Interrupt
  • Flush Output
  • Are You There
  • Kill
  • Erase
  • Quit

With local characters:

  • Enabled --- The local host sends the control characters (in the preceding text) translated into TELNET sequences. For example, Ctrl/T becomes IAC AYT.
    Enabled mode is appropriate when the remote and local hosts implement different control characters. The remote host does not recognize certain control characters. Therefore, the local host interprets these control characters before sending them to the remote host.
  • Disabled --- The local host sends these control characters uninterpreted. They are interpreted by the remote host.
    Before you communicate in disabled mode, ensure that the remote and local hosts use the same control characters.

Default: DISABLE LOCAL_CHARS

DCL Format

ENABLE LOCAL_CHARS

DISABLE LOCAL_CHARS

UNIX Format

toggle localchars

ENABLE (DISABLE) OPTIONS_VIEW

Enables or disables the display of option negotiations between the local system and the remote host during the session.
  • Enabled --- TELNET displays the option negotiations between your local system and the remote host.
  • Disabled --- TELNET does not display the option negotiations. This mode is suitable for most communications.

Default: DISABLE OPTIONS_VIEW

DCL Format

ENABLE OPTIONS_VIEW

DISABLE OPTIONS_VIEW

UNIX Format

toggle options

EXIT

Closes any open sessions, exits from TELNET, and returns to the DCL prompt.

If you terminate a session with a remote OpenVMS host, the connection is closed by your local host. However, the process on the remote host is still running. To terminate it, enter the LOGOUT command.

DCL Format

EXIT

UNIX Format

quit

HELP

Displays online help for TELNET or TN3270 commands.

Format

HELP [ telnet_command ]

Parameters

telnet_command

Optional.

Specific DCL TELNET command about which you want information.

Examples

#1 

TELNET> HELP CONNECT

Provides information about the CONNECT command.

#2 

TELNET> HELP OPEN

Displays the message Sorry, no documentation on OPEN .

To get help for a command, enter the DCL command name.

RESUME

Resumes an open TELNET or TN3270 session that you interrupted with the escape sequence. When you run simultaneous multiple sessions (TELNET only):
  • To resume a particular session, specify a session number.
  • To resume the active session, omit the session number.
  • If no session is active, you must specify a session number.

    Note
    TELNET interprets the active session as the last session with which you communicated. If that communication ended with you logging out, you have no active sessions. However, you might have other waiting (alive) sessions.

DCL Format

RESUME [ session_number ] [Return]

UNIX Format

[Return]

Parameters

session_number

Optional. Default: the active session.

Use session_number when you run multiple TELNET sessions. It resumes the session with the specified number.

Examples

#1 

$ [Ctrl/]] (characters not echoed)
TELNET> SHOW STATUS [Return]
Session  1 Active  Host FINDER
   .
   .
   .
TELNET> RESUME [Return]
$

This example:

  • Starts at the prompt of remote OpenVMS host FINDER.
  • Escapes from FINDER and returns to the local TELNET prompt.
  • Issues SHOW STATUS, which displays one active session.
  • Returns to FINDER's prompt.
#2 

% [Ctrl/]] (characters not echoed)
TELNET> SHOW STATUS [Return]
Session  2 Active  Host LUNA
   .
   .
   .
Session  1 Waiting Host SOLAR
TELNET> RESUME 1 [Return]
%

This example:

  • Starts at the prompt of UNIX host luna .
  • Escapes from luna .
  • At the TELNET prompt, issues SHOW STATUS, which displays two active sessions, the active one with luna and another with host solar , whose status is "waiting."
    The RESUME 1 command returns to "waiting" host solar .

SEND AO

SEND AO (Abort Output) aborts the output of the last remote command you entered, while the command continues to execute. If you issue another SEND AO, the output resumes if the command is still executing.

Use this command when the following conditions exist:

  • The remote host does not recognize Ctrl/O as the flush output character.
  • You want to terminate the output but not the execution of the process.

DCL Format

SEND AO

UNIX Format

send ao

Example


% cd /bin
% ls -l
total 3464
-rwxr-xr-x  2 root 32768 Oct 19  1996 STTY
-rwxr-xr-x  2 root  5120 Oct 19  1996 [Ctrl/]]  (characters not
echoed)
TELNET> SEND AO
^O
%

During a directory listing, the TELNET escape sequence (not echoed to the screen) returns to TELNET prompt. The SEND AO command aborts the UNIX ls command.

SEND AYT

SEND AYT (Are You There) reports if you are still connected to an established connection.

DCL Format

SEND AYT

UNIX Format

send ayt

EXAMPLES

#1 

$ [Ctrl/]]
TELNET> send ayt
%TELNET-I-SESSION, Session 01, host d45lt, port 23
$
$:_TNA375: 13:53:18 (DCL) CPU=00:00:00.28 PF=448 IO=104 MEM=53
$

VMS client to VMS server.

#2 

% [Ctrl/]]
TELNET> send ayt
%TELNET-I-SESSION, Session 01, host LUNA, port 23
%
[YES]
[Return]
%

VMS client to UNIX server.

#3 

$ [Ctrl/]]
telnet> send ayt

$:_TNA37: 13:50:20 (DCL) CPU=00:00:00.12 PF=331 IO=98 MEM=66
$

UNIX client to VMS server.

#4 

% [Ctrl/]]
telnet> send ayt

[Yes]
[Return]
%

UNIX client to UNIX server.

SEND BRK

SEND BRK (Break) terminates execution of the last command you entered at the remote host.

Use this command when the remote host does not recognize Ctrl/C as an interrupt character.

DCL Format

SEND BRK

UNIX Format

send brk

Example


% cd /bin
% ls -1
total 1464
-rwxr-xr-x  2 root 32768 Oct 19  1988 STTY
-rwxr-xr-x  2 root 5120  Oct 19  1988 [
-rwxr-xr-x  1 root 45056 Oct 19  1988 adb
lrwxr-xr-x  1 root   13  Aug 21 17:41 ar -> ../usr/bin/ar
lrwxr-xr-x  1 root   13  Aug 21 17:41 as -> ../usr/bin/as
[Ctrl/]] (characters not echoed)
TELNET> SEND BRK

This example does the following:

  • Enters the UNIX ls command.
  • Enters the TELNET escape sequence.
  • Enters the TELNET SEND BRK command, which terminates execution of ls at the remote host.

SEND EC

SEND EC (Erase Character) deletes the last character you typed at the remote host.

Use this command when the remote host does not recognize your Delete key.

DCL Format

SEND EC

UNIX Format

send ec

Example


% mail [Ctrl/]] (characters not echoed)
TELNET> SEND EC [Return]
Mail $Revision 4.2.4.2 $  Type ? for help.
"/usr/spool/mail/debts": 1 message 1 new
>N  1 debts  Tue Sep 15 13:39  8/161  "Team Building"
&

This example:

  • Misspells the UNIX mail command.
  • Enters the TELNET escape sequence (not echoed to the screen) to return to the TELNET prompt.
  • Enters the TELNET SEND EC command, which deletes the last character typed (l) and returns to the remote host.

SEND EL

SEND EL (Erase Line) deletes the last line of text you entered on the remote host.

Use this command when the remote host does not recognize your Delete key or command-line recall.

DCL Format

SEND EL

UNIX Format

send el

Example


% mail [Ctrl/]]   (characters not echoed)
TELNET> SEND EL [Return]
% Mail
Mail version 2.18 5/19/83.  Type ? for help.
"/usr/spool/mail/finder": 1 message 1 new
>N  1 finder  Tue Sep 15 13:39  8/161  "Getting Together"
&

This example:

  • Misspells the UNIX Mail command.
  • Enters the TELNET SEND EL command, which deletes the incorrect line mail and returns you to the remote host.
  • Enters the Mail command.

SEND GA

SEND GA (Go Ahead) signals the remote host that your local system is ready.

Some applications require GA commands in either one or both directions. (Usually, Go Ahead is suppressed, so sending a GA has no effect.)

DCL Format

SEND GA

UNIX Format

send ga

SEND IP

SEND IP (Interrupt Program) interrupts the execution of the last command you entered on the remote host. The interrupt character clears the input and output paths to the remote host. The remote host interrupts the program that is processing. (This command has no effect in binary mode.)

Use this command if either your terminal or the remote host does not recognize the default interrupt character, Ctrl/C.

DCL Format

SEND IP

UNIX Format

send ip

SEND NOP

SEND NOP (No Operation) tells you whether your local host can send data to the remote host and the remote host can receive the data. If you:
  • Get an %TELNET-E-INETERROR error message, there is a problem with the connection; the remote host is not able to receive data.
  • Get an %TELNET-S-REMCLOSED status message, the connection with the remote host has been closed.
  • Do not get an error message, the connection is active.

DCL Format

SEND NOP

UNIX Format

send nop

Examples

#1 

% [Ctrl/]] (characters not echoed)
TELNET> SEND NOP [Return]
%TELNET-I-SESSION, Session 01, host nyx, port 23

No error message indicates the connection is active. (The information message also indicates the connection is active.)

#2 

% [Ctrl/]] (characters not echoed)
TELNET> SEND NOP
%TELNET-S-REMCLOSED, Remote connection closed
-TELNET-I-SESSION, Session 01, host nyx, port 23
TELNET>

Indicates your connection has been broken.

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