Determining if a Terminal is a DecTerm or not?

[Jimson_1]

Hi,

Anyone know of a quick way to determine if a terminal is a DecTerm or Not?

Maybe one of the items for F$GETDVI() but I couldn't see it.

James

[Bart Zorn_1]

James,

I do not know of a definitive way of deciding about this.

If you are NOT at a FTAn: device, it is not a DECterm.

If you are at a FTAnn: device, you are more or less stuck.

If you issue a SET TERMINAL/INQUIRE command on a DECterm, the device_type will be set to VT300_Series. This can be detected with f$getdvi("sys$command","device_type_name") which will return "VT300 Series", without the underscore.

If you are at a FTAnn: device and it reports being a "VT300 Series" than there is a good chance that your have a DECterm, but this is probably not water tight! And this will only work if you do the SET TERM/INQUIRE first!

HTH!

Bart Zorn

[Steven Schweda]

> If you are NOT at a FTAn: device, it is
> not a DECterm.

Really? On my (CDE/"New") desktop, after I
"SET HOST 0", I seem to have a DECterm which
is not an FTAn:

alp $ show terminal
Terminal: _RTA2: Device_Type: VT300_Series Owner: _RTA2:
Username: SMS
Remote Port Info: ALP::SYSTEM
[...]


Or, if I Telnet back in:

alp $ show terminal
Terminal: _TNA79: Device_Type: VT300_Series Owner: _TNA79:
Username: SMS
Remote Port Info: Host: 10.0.0.9 Locn: _RTA1:/SMS
[...]


(SSH _does_ give an FTA, however.)

Presumably, one could send a magic escape
sequence and get a DECterm-specific response,
but, because the "Options"->"General..."
menu offers a wide assortment of possible
"Terminal ID" responses, you probably
shouldn't rely on that result.


An interesting question might be, Why do you
care?


(Send a different magic escape sequence to
have the title bar ask, "IS THIS A DECterm?",
and wait for the victim to answer? If you
don't hear back, he must not have seen the
question. (Of course, _he_ could lie, too.))

[Jimson_1]

Thanks for the responses.

Answering your question, Why do I care? Well, I don't really, but someone else in the office was asking how to do it.

Being a considerate sort of person, I offered to find out, only realising now that its not that straightforward.

Maybe, I'll go and ask him why he cares?

Thanks anyway

JamesP

[Steven Schweda]

> Being a considerate sort of person, [...]

Well, I hope you've learned _your_ lesson.

[Jimson_1]

Believe me, never again...

[Colin Butcher]

Assuming that you mean a DECwindows DECterm, not a physical DEC terminal device (VTxxx) or Powerterm-like terminal emulator, many years ago I wrote some DCL for SYLOGIN that did things like this.


Here's an extract:

$ if f$getdvi("tt:","exists")
$ then
$ this_ttdev = f$getdvi("tt:","fulldevnam") - "_" - ":" - "''this_scsnode'$" - "$''this_alloclass'$"
$ else
$ this_ttdev = ""
$ endif

...


$ !
$ ! Fast login users/sessions (Network users, DECW session manager and
$ ! DECW application detached processes).
$ !
$ if this_username .eqs. "DECNET" .or. -
this_username .eqs. "RSM$CMANAGER" then exit
$ !
$ if f$mode() .eqs. "INTERACTIVE" .and. -
((f$locate("WSA",this_ttdev) .ne. f$length(this_ttdev)) .or. -
(f$locate("MBA",this_ttdev) .ne. f$length(this_ttdev))) then exit
$ !

Might be useful. You could do all sorts of other terminal device type [TXA / WSA / MBA / TA / ...] (as opposed to terminal type [VT300 / Powerterm ...]) stuff if you needed to.

Hope that helps.

Cheers, Colin (http://www.xdelta.co.uk).

[Steven Schweda]

> If you are NOT at a FTAn: device, it is
> not a DECterm.

I forgot SET HOST /LAT:

WIMP $ show terminal
Terminal: _LTA1: Device_Type: VT300_Series Owner: SYSTEM
LAT Server/Port: ALP/UIC_000001000004


If you need any more useless information,
feel free to ask.


Looking through the C header files, I did
spot ptd$decterm_set_page_size() in
STARLET.H. Perhaps it can tell a DECterm
from something else. (Novel error status?
No bets.)

[Jimson_1]

Thanks guys for your replies.

Be sure, more useless questions appearing over the coming months....

[Jimson_1]

Thread closed