[Info-vax] escape sequences, cursor positioning

[Neil Rieck]

On Jan 11, 3:49 am, acid.fri... at yahoo.de wrote:
> hi everybody,
> it might be interesting for you to read my previous topic:http://groups.google.com/group/comp.os.vms/browse_thread/thread/37b3e...
>
> in the meantime i managed to get a copy of vt100 user guide and i've
> read the programmers part very carefully, because i want to code
> something in DCL using ASCII escape sequences.
> i've found out that some escape seqences work very well and other
> don't work and now i'm trying to find some help here.
>
> $ ty specfont.com
> $!------------------------------------------------------------------------------
> $!                                                   PLAYING WITH ESC
> SEQUENCES
> $!------------------------------------------------------------------------------
> $!
> $ esc[0,7] = 27
> $ say = "write sys$output"
> $ say esc+ "(0"
> $ say " ssssssssss"
> $ say esc+ "(A"
> $ say esc+ "[3A"
> $ read sys$command input1/prompt=" "
>
> this works fine ^^
>
> but when i modify the "$ say " ssssssssss" line and add a additional
> escape seqence, it won't work.
>
> $ ty specfontv2.com
> $!------------------------------------------------------------------------------
> $!                                                   PLAYING WITH ESC
> SEQUENCES
> $!------------------------------------------------------------------------------
> $!
> $ esc[0,7] = 27
> $ say = "write sys$output"
> $ say esc+ "(0"
> $!
> $! modified line below, added some spaces in front of the first s
> $ say "   ssssssssss"
> $!
> $ say esc+ "(A"
> $ say esc+ "[3A"
> $!
> $! additional escape sequence below, want the cursor so move right
> (this won't work)
> $ say esc+ "[2C"
> $!
> $ read sys$command input1/prompt=" "
>
> okay, that's my first problem.
>
> besides i don't want the underscores/special characters to get
> overwritten when i start typing.
> is there any easy solution for this?
>
> kind regards

Maybe this is something I haven't seen before but, shouldn't the "7"
be an "8" as in:
$ esc[0,8]=27
I thought "8" meant byte but maybe its just my ignorance showing
though.

With respect to VT control codes, I have been doing this with hardware
terminals and/or emulators since 1987 (from DCL but mostly from BASIC)
and have used a declaration file similar to this one.

http://www3.sympatico.ca/n.rieck/demo_vms/device_controls.zip

Neil Rieck
Kitchener/Waterloo/Cambridge,
Ontario, Canada.
http://www3.sympatico.ca/n.rieck/links/openvms_demos.html