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Conference noted::hackers_v1

Title:-={ H A C K E R S }=-
Notice:Write locked - see NOTED::HACKERS
Moderator:DIEHRD::MORRIS
Created:Thu Feb 20 1986
Last Modified:Mon Aug 03 1992
Last Successful Update:Fri Jun 06 1997
Number of topics:680
Total number of notes:5456

31.0. "Real hacker problem?" by GVA04::BETTINA () Mon Jul 16 1984 13:43

Hi everybody!

I think that the following is a nice hacker problem.

I would like to have a possibility to invoque any time a parrallel process 
while doing an other one, and comming back to the originel one. For example, I 
would like to be able to go the DCL commands while editing (to get some info
about whatever), and then get back to the same place I left in the editor.

I thought about using a shell and working on two processes all the time, but
that would clogg the system slightly. Thus a hibernating process should be 
used. But how can I call it without getting down to DCL commands?

Who has done a programm to solve this problem? (Note that I am not a hacker,
wizzard, guru, or whatsoever, so that I need an easy answer. Note also that I 
am working on a VAX).
T.RTitleUserPersonal
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31.1OBIWAN::PFAUMon Jul 16 1984 10:3610
If you find the need to issue DCL commands while in the editor, type a 
^Y and 'SPAWN'.  This will leave your process in the editor and you 
can do whatever you want in the subprocess.  When you wish to get back 
to the editor, just log out, type 'CONTINUE' and hit a ^W to refresh
the editor screen. 

This method should work for just about anything that doesn't trap a 
^Y.

tom p
31.2REGINA::AUGERIMon Jul 16 1984 10:388
You can use the EMACS editor on the VAX to do what you want. EMACS has
multi-windowing and one of the features that is available is the abiltity
to set-up a DCL commmand window, which you can switch to to pass commands
to DCL, and a DCL output window that collects the output from from DCL. A
nice feature is that both windows can be edited. A disadvantage is that it
does create sub-processes which use up resources.

	Mike
31.3Vaxuum::DYERMon Jul 16 1984 19:246
	The EMACS subprocess does go into hibernation, though.
	It's probably a bit wiser to create a subprocess with your editor
in it, ^Y out when you need to and ATTACH to the main process.  This saves
time that would be spent continually SPAWNing a subprocess every time you
want to use DCL.
		<_Jym_>
31.4GVA04::BETTINATue Jul 17 1984 12:1410
Thanks for your help. I will use it for some applications.

But I would not restrict myself to the editor. Using slide takes quite a lot 
to get get out of, or DECgraph. In this case you cannot use ^Y, and since you
spent quite a lot of time in these applications, it is not profitable to have
all the time 2 processes running.

Cheers.
						Bettina (Geneva)
31.5TRIVIA::MUNYANTue Jul 17 1984 15:1412
Although this isn't a hack you might try getting a LAT in your area...
that way you can just press BREAK and start up a new job... you can
then switch back and forth by typing FOR or defining a switch character.

Personnally I use both the LAT and EMACS... (I got very dependant on EMACS
after working with 20's for 3.5 years) VMS is finally catching up but still
hasn't totally figured out how to bounce around between processes yet...

Ie: on a 20 I can create a new FORK a lot quicker than I can spawn.

Steve
31.6Vaxuum::DYERTue Jul 17 1984 20:133
	Note that a number of utilities (DEBUG and MAIL, for example) will
let you SPAWN.  DEBUG will even let you ATTACH somewhere!
		<_Jym_>
31.7ACE::BREWERFri Jul 20 1984 13:556
	It seems to me that if you are in the EDT editor, and type a ^Y,
all you'll get is booted back to the $ sign, and a .jou file out of the
editor. Same w/MAIL. Or you talking about a different editor?

	-John
31.8OBIWAN::PFAUFri Jul 20 1984 17:405
If you are in the middle of a long edit with EDT, do you really want 
to do a recover and wait for EDT to process all those keystrokes?  
It's much easier to ^Y and spawn.

tom p
31.9ACE::BREWERFri Jul 20 1984 17:198
	But I dont understand! As soon as I hit ^y Im gone out of edt! I 
created a .JOU.! Mabye we should continue off-line, but... It seems that
if I return to a $prompt I have to do a RECOVER. CONTINUE does something but
still leaves me at the $, not back in EDT.

	Confused in ABO
	-John :-<
31.10XENON::MUNYANSat Jul 21 1984 00:009
I agree with John (.9)... I've occassionally done the CTRL/Y CONTINUE
trick and gotten burned... Thank god for EMACS... Hitting CTRL/C invokes
the command pause-emacs... this brings me back to DCL... typing EMACS
re-attaches me to the EMACS process.  Re-attaching normally takes 1-2
seconds unless it's been a long period of time (and VMS has swapped my
EMACS process out)

Steve
31.11OBIWAN::PFAUMon Jul 23 1984 12:3013
When you hit a ^Y, an AST is delivered to your CLI.  The image you 
were executing is still mapped.  If you type CONTINUE, you will resume 
where you left off.  There are certain commands which you can enter 
while in a ^Y interupt state which do not affect the currently 
executing image.  These are documented somewhere, don't remember 
where.  SPAWN is one of these commands.  You can spawn a subprocess, 
do whatever you like, log out (of the subprocess), type continue and 
be on your merry way.

I will try to find the documentation on the commands which do not 
affect a currently executing image.

tom p
31.13NACHO::CLEVELANDTue Aug 21 1984 17:074
The commands are given on page 4-8 of the CLUG (command language user's 
guide).

tc