Document revision date: 19 July 1999
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OpenVMS DCL Dictionary


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SET HOST

Connects your terminal (through the current host processor) to another processor, called the remote processor. The command requires that:

Format

SET HOST node-name


Parameter

node-name

Specifies the node name of the remote processor to which you will connect.

Description

The SET HOST command connects you to another processor on a network. (The SHOW NETWORK command lists the names of nodes accessible to your node.) Once the connection is made, the remote processor prompts for a user name and password. You must have an account on the remote processor to log in.

Once you have connected to the remote processor and have logged in, you can use DCL commands just as you would on your local processor. You can even use the SET HOST command to connect to another remote processor.

For example, if your local node is BOSTON, you can use the command SET HOST ALBANY to connect to the node ALBANY. You can then use the command SET HOST AKRON to connect (still through BOSTON and ALBANY) to the node AKRON.

Use the LOGOUT command to log out of the last processor you have logged in to and return to the previous processor. For example, when you use the LOGOUT command, you have logged out of (and disconnected from) the processor at node AKRON, but you are still logged in (and connected) to the processor at ALBANY. A second LOGOUT command logs you out of node ALBANY, and disconnects you from it. A third LOGOUT command logs you out of the local processor, BOSTON.

You can also abort operations and return directly to the original host processor, if necessary. Press Ctrl/Y at least two times in rapid succession. The following message is displayed:


Are you repeating ^Y to abort the remote session? 

If you respond Y or YES, control returns to the original node. Other responses, such as N or NO, do not abort the connection. This technique is useful when you want to exit quickly without entering a series of LOGOUT commands, or when part of the network becomes disconnected and you want to return to the host.

Note that SET HOST, unlike the OpenVMS terminal driver, buffers output data from an executing program. Buffering improves performance in wide-area networks. However, in the case of programs providing output only, the buffering causes a discrepancy between what is happening in the remote program and what is displayed on the local terminal. That is, a program might finish executing before you see the output on the local terminal.

This discrepancy can be particularly confusing when you use the Ctrl/Y or the Ctrl/C function, or out-of-band abort characters to abort the execution of a program. For example, when you press Ctrl/Y or Ctrl/C (or enter out-of-band abort characters) during the execution of a captive command procedure, SET HOST immediately stops the display on the local terminal. It also aborts the current read and write operations and any pending write operations, including all buffered write operations.2 Therefore, although it seems that the remote program aborts at the point in the program at which the display on the local terminal is stopped, the program might have executed beyond that point already---and might have finished executing---before you pressed Ctrl/Y.

Note that several SET HOST qualifiers, such as /MOP, /VTP, and /X29, are available only if DECnet-Plus is installed on your system. For information about using these qualifiers, type the following command:


$ HELP DECnet-Plus 


Qualifiers

/APPLICATION_PROTOCOL[=protocol]

Specifies the protocol connection, CTERM (CTDRIVER) or RTERM (RTTDRIVER) on the specified node. CTERM protocol is the default if no connection is specified.

/BUFFER_SIZE=n

Changes the packet size of the protocol message sent between the terminal and the remote processor if a connection to the remote processor is already established. The default buffer size is 1010 bytes; however, the buffer size n can range from 140 bytes to 1024 bytes. The value of the parameter n is reset to 140 bytes if a value below 140 is specified; a value for n above 1024 bytes is reset to 1024.

You can force the host node to write to the terminal in smaller packets, thereby ensuring that write operations to the terminal are displayed at more frequent intervals, by setting n to a value just above the minimum of 140 bytes. On slow DECnet links, setting the buffer size to a smaller value may decrease pauses between write operations when large amounts of data are being scrolled to the screen.

/LOG[=filespec]

/NOLOG (default)

Controls whether a log file of the entire session is kept. If you use the /LOG qualifier without the file specification, the log information is stored in the file SETHOST.LOG.

/RESTORE

/NORESTORE (default)

Saves current terminal characteristics before a remote terminal session is begun and restores them when the remote session is terminated.

Examples

#1

$ SET HOST/APPLICATION_PROTOCOL=CTERM DAKOTA
      

The /APPLICATION_PROTOCOL qualifier specifies the CTERM protocol (the default) on node DAKOTA in this command line.

#2

$ SET HOST ITALIC
Username:  GRESOV
Password: <PASSWORD>
    Welcome to OpenVMS VAX Version 7.1 on node ITALIC
   .
   .
   .
$  LOGOUT
GRESOV logged out at 19-DEC-1998 15:04:25.27
%REM-S-END, Control returned to node _CASLON::
 
      

In this example, the name of the local node is CASLON. This SET HOST command connects the user terminal to the processor at the network node named ITALIC. The remote processor then prompts for user name and password. Use the normal login procedure to log in to the remote processor.

Once you are logged in at a remote node, you can use the SET HOST command to establish communication with another node. After logging in to node ITALIC, you could type SET HOST BODONI.

You would again be prompted for a user name and password. If you then supply a valid user name and password, you will be logged in to node BODONI.

Note that when you log out of node BODONI, control is returned to node ITALIC. You must log out of node ITALIC to return to your local node, CASLON.

#3

$  SET TERMINAL/WIDTH=80
$  SET HOST/RESTORE GENEVA
Username: Jones
Password: <PASSWORD>
$  SET TERMINAL/WIDTH=132
   .
   .
   .
$  logout
JONES   logged out at 19-DEC-1998 11:04:51.45 
%REM-S-END, control returned to node _ORACLE 
 
      

This example shows user JONES on node ORACLE logging in to remote node GENEVA and specifies that the original terminal screen width be restored to 80 characters when the remote session is terminated.

Note

1 Available under separate license.
2 DCL always maintains an outstanding Ctrl/Y asynchronous system trap (AST) to the terminal driver. When you press Ctrl/Y, the terminal driver aborts the current read and write operations and any pending write operations, including all buffered write operations.

SET HOST/DTE

Connects your system to a remote system through an outgoing terminal line.

You must have an account on the remote system in order to log in to that system after the connection is made. You must also have the ability to assign a channel to the terminal port specified. Your system manager can set the device protection on the terminal port to allow you access.


Format

SET HOST/DTE terminal-name


Parameter

terminal-name

Specifies the name of an outgoing terminal line, which connects your system directly to another system or modem.

Description

The SET HOST/DTE command allows you to connect your terminal to another system. Once the connection is made, the remote system prompts for a user name and password. You must have an account on the remote system to log in.

Once you have logged in to the remote system, you can use DCL commands just as you would on your local system.

To log in on lines that expect a break rather than a carriage return, press Ctrl/break-character to generate the break.

While connected to the remote system, you can issue configurational commands from DTE command mode. DTE commands enable you to configure a SET HOST/DTE session while it is in progress.

To issue DTE commands, you must get into DTE command mode by pressing Ctrl/command character. By default, the command character is the at sign (@). Once you are in command mode, the DTEPAD prompt will be displayed on your screen.

Table DCLII-19 describes the DTE commands.

Table DCLII-19 SET HOST/DTE Session Commands
Command Description
CLEAR Disconnects your local system from DTEPAD. This command is equivalent to the QUIT command.
EXIT Returns the session to emulation mode.
QUIT Disconnects your local system from DTEPAD. This command is equivalent to the CLEAR command.
SAVE filespec Saves information on the current configuration settings. The current settings are written to the specified file as a series of SET DTE commands. You can later use this file as an initialization file.
SEND BREAK Sends a break to remote systems that expect a break rather than a carriage return.
SET DTE Modifies configurable characteristics of DTEPAD while in a SET HOST/DTE session. You can use the SET HOST/DTE qualifiers in command mode.
SHOW DTE Displays the current settings of all the configurable characteristics of DTEPAD. It also displays the number of bytes of data transmitted and received during the current SET HOST/DTE session and the number of errors detected by the terminal port.
SPAWN Creates a subprocess of your current local process. The command is identical to the DCL SPAWN command except that the DTE SPAWN command has fewer qualifiers, as follows:
  • /INPUT=filespec
  • /LOGICAL_NAMES and /NOLOGICAL_NAMES
  • /OUTPUT=filespec
  • /PROCESS=subprocess-name
  • /SYMBOLS and /NOSYMBOLS
  • /WAIT and /NOWAIT

See the SPAWN command in this manual for more information about these qualifiers.

To terminate a session, you should first log out of the remote system. Then quit DTEPAD by pressing Ctrl/escape-character. By default, the escape character is a backslash (\). Alternatively, quit DTEPAD by entering the QUIT or the CLEAR command from DTE command mode.


Qualifiers

/BREAK=break-character

Selects the break character. The break character is used to generate a break on lines that expect a break rather than a carriage return. To generate a break, press Ctrl/break-character.

The break character can be any ASCII character between @ and z, except C, M, Q, S, Y, or the left bracket ([). You cannot select a character currently defined as either the command character (see the description of the /COMMAND=command-character qualifier) or the escape character (see the description of the /ESCAPE=escape-character qualifier).

The ASCII characters between @ and z include the alphabetic characters in both upper and lower cases, the at sign (@), the backslash (\), the right bracket (]), the circumflex (^), the underscore (_), and the grave accent (`).

By default, the break character is the right bracket (]).

/COMMAND=command-character

Selects the command character. Use the command character to access DTE command mode by pressing Ctrl/command-character.

The command character can be any ASCII character between @ and z, except C, M, Q, S, Y, or the left bracket ([). You cannot select a character currently defined as either the break character (see the description of the /BREAK=break-character qualifier) or the escape character (see the description of the /ESCAPE=escape-character qualifier).

The ASCII characters between @ and z include the alphabetic characters in both upper and lower cases, the at sign (@), the backslash (\), the right bracket (]), the circumflex (^), the underscore (_), and the grave accent (`).

By default, the command character is the at sign (@).

/DIAL=(NUMBER:number[,MODEM_TYPE:modem-type])

Allows a modem attached to the outgoing terminal line to be autodialed using the autodial protocol of that modem. The NUMBER keyword is the telephone number to be autodialed and is a required parameter.

Before you dial a new number, you must log out of the current remote system.

On Alpha, the MODEM_TYPE keyword defaults to DMCL (any modem that uses the DEC Modem Command Language).

On VAX, the MODEM_TYPE keyword is optional. It can be used to specify any of the following modem types:

Each modem type requires a specific modem dialer code. Check with your system manager to see which modem dialer codes are installed on your system.

In addition, the MODEM_TYPE keyword can be used to specify a modem type other than DF03, DF112, or DMCL. A template is provided for users interested in supporting other modems with autodial capabilities (see SYS$EXAMPLES:DTE_DF03.MAR).

/ECHO

/NOECHO (default)

Determines whether the terminal input is echoed by your local system. By default, all echoing is performed by the remote system.

/EIGHT_BIT (default)

/NOEIGHT_BIT

Determines whether the outgoing terminal line supports 8-bit or 7-bit characters. By default, 8-bit characters are supported. If you specify /NOEIGHT_BIT, then 7-bit characters are supported.

/ERROR_ACTION=CONTINUE (default)

/ERROR_ACTION=EXIT

Specifies the error action by using the EXIT or the CONTINUE keyword.

When an error is detected on the outgoing terminal line, the error is reported to the local system and an error message is displayed on your terminal.

If the error action is CONTINUE, then communication with the remote system continues uninterrupted.

If the error action is EXIT, then the local system immediately exits from the remote system.

/ESCAPE=escape-character

Selects the escape character. You can use the escape character to exit from DTEPAD by pressing Ctrl/ escape-character.

The escape character can be any ASCII character between @ and z, except C, M, Q, S, Y, or the left bracket ([). You cannot select a character currently defined as either the break character (see the description of the /BREAK=break-character qualifier) or the command character (see the description of the /COMMAND=command-character qualifier).

By default, the escape character is a backslash (\).

The ASCII characters between @ and z include the alphabetic characters in both upper and lower cases, the at sign (@), the backslash (\), the right bracket (]), the circumflex (^), the underscore (_), and the grave accent (`).

/FLOW_CONTROL (default)

/NOFLOW_CONTROL

Determines whether XON/XOFF flow control is enabled. By default, flow control is enabled.

XON/XOFF flow control is a means of preventing data-overrun errors. Incoming data is stored in receive buffers; when these buffers are full, a signal is sent to the remote system to stop transmission. Once there is sufficient space in the receive buffers, another message is sent to restart transmission.

You should disable XON/XOFF flow control when the remote system has no XON/XOFF flow control.

/INIT[=filespec] (default)

/NOINIT

Sets the configurable characteristics of DTEPAD according to values contained in the specified initialization file.

If you use qualifiers in the command line to define the values of any of the configurable characteristics, these will supersede the values contained in the initialization file.

By default, DTEPAD tries to translate the logical name DTEPAD$INI in order to find the appropriate initialization file. If you use the /INIT qualifier and omit the file specification, DTEPAD translates the logical name DTEPAD$INI and finds the appropriate file. If DTEPAD$INI is not defined, then DTEPAD uses /NOINIT as the default.

An initialization file can contain any combination of any of the following DTE commands:

The following is an example of an initialization file:


SET DTE/MAX_BUFFERS=150 
SET DTE/READ_DELAY=100 
SEND BREAK 

/LOG[=filespec]

/NOLOG (default)

Controls whether a log file of the session is kept.

If you use the /LOG qualifier and omit the file specification, then the log information is written to the file DTEPAD.LOG.

When used to log a modem session, the log file contains any noise that occurred on the phone line. For example, typing a file in order to get it recorded in the log file could result in noise being recorded along with the file data. Therefore, the use of a log file is not recommended for the purpose of file transfers.

Compaq recommends that you use asynchronous DECnet to transfer files.

/MAX_BUFFERS=number-buffers

Specifies the maximum number of receive buffers. Receive buffers are buffers used to receive incoming data from the modem port. They are allocated as they are required.

By default, the maximum number of receive buffers is 100. The minimum number you can specify is 20.

/PARITY=NONE (default)

/PARITY=ODD

/PARITY=EVEN

Selects parity on the outgoing terminal line.

/READ_DELAY=delay

Specifies the modem port read delay in milliseconds. The modem port read delay is the time interval during which data in the modem port is transferred into receive buffers at the terminal.

By default, the modem port read delay is 50 milliseconds. This is also the minimum value.

A long modem port read delay slows the rate at which data is displayed at your terminal, and also increases the risk of data-overrun errors; however, a longer read delay requires less CPU overhead.

/SPEED=(output-rate,input-rate)

Sets the baud rate at which the terminal receives and transmits data. If the input and output rates are the same, specify the qualifier as /SPEED=rate.

Not all terminals support different input and output baud rates. For specific information on baud rates for your terminal, consult the manual for that terminal.

The default transmission rates are installation dependent.

The valid baud rates are as follows:


 50       150       1800       4800       38400 
 75       300       2000       7200       57600 
110       600       2400       9600       76800 
134      1200       3600      19200      115200 

If you select an invalid or unsupported speed, then the terminal line speed will remain set at its previous value.


Examples

#1

$ SET HOST/DTE TTA2:/DIAL=NUMBER:5551234
Username: SMITH
Password: 
      

This command connects the user terminal to the outgoing terminal line TTA2:, which is attached to a modem (type DF03 by default) set to autodial the phone number 555-1234. The remote processor then prompts for user name and password. Use the normal login procedure to log in to the remote system.

#2

$ SET HOST/DTE/DIAL=(NUMBER:5551234#,MODEM_TYPE:DF112) TTA2:
Username: SMITH
Password: 
      

This command accomplishes the same thing as in the first example, except that it uses the DF112 modem. The number sign (#) is required to activate the autodialer in the DF112.

#3

$ SET HOST/DTE/NOEIGHTBIT TTA2
      

This command sets the outgoing terminal port, TTA2, to support 7-bit characters.

#4

$ SET HOST/DTE/NOFLOW_CONTROL TTA2
      

This command disables the XON/XOFF flow control.

#5

$ SET HOST/DTE/ERROR_ACTION=EXIT TTA2
      

This command sets the error action to EXIT.

#6

$ SET HOST/DTE/MAX_BUFFERS=150 TTA2
      

This command sets the maximum number of receive buffers to 150.

#7

$ SET HOST/DTE/ESCAPE=E TTA2
      

This command defines the letter E as the escape character. Note that DTEPAD is not case sensitive.

#8

$ SET HOST/DTE/LOG TTA2
      

This command enables logging of the session. Since no log file is specified, the log is written to the default log file, DTEPAD.LOG.

#9

$ SET HOST/DTE/INIT=MYFILE.INI TTA2
      

This command uses the initialization file MYFILE.INI.

#10

$ [Ctrl/]@
DTEPAD>
      

This example shows you how to access DTE command mode by pressing Ctrl/@, where @ is the command character.

#11

DTEPAD> SAVE MYFILE.INI
      

This command saves the information on the current configuration in the file MYFILE.INI.

#12

DTEPAD> SET DTE/BREAK=G
      

This command defines the letter G as the break character.

#13

DTEPAD> SET DTE/ECHO
      

This command sets the terminal port so that echoing is performed by the local system.

#14

DTEPAD> SET DTE/SPEED=4800
      

This command sets the input and output baud rates to 4800.

#15

DTEPAD> SET DTE/LOG=myfile.log
      

This command directs logging to the file MYFILE.LOG.

#16

DTEPAD> SHOW DTE
  Port TXA0              EIGHT_BIT ECHO
  Flow control           XON/XOFF
  Parity                 NONE
  Transmit Speed         4800
  Receive Speed          4800
  Error action           CONTINUE
  Break character        B
  Escape character       \
  Command character      @
  Maximum buffers        100
  Read delay             50 milliseconds
  Log file               MYFILE.INI
  Number dialed          12345678
  Modem type             DF03
  Bytes transmitted      75
  Bytes received         132
  Errors                 0
 
      

This command displays all the current settings of the configurable characteristics, the number of bytes transmitted and received, and the number of errors detected.


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