1. Newby with a Ctrl-C problem
Greetings Euphorians,
Please excuse me if I'm breaking any etiquette rules here ( can't get at
alt.lang.euphoria from behind our firewall and haven't had time to
plough through the archived material ) ...
I'm new to Euphoria - I was so impressed by what I saw when I discovered
the language I have decided to use it on my latest project, however, as
with all languages ( trying to run before I can walk ), I've hit a
problem ...
I *must* be able to trap and handle Ctrl-C within my application -
Using allow_break(TRUE) causes the app. to exit to MS-DOS as soon as
Ctrl-C appears.
Using allow_break(FALSE) prevents the exit to MS-DOS but get_key()
doesn't return anything so I can't tell that Ctrl-C has turned up and
handle it 
Anyone got any suggestions / solutions ?
Many thanks in anticipation,
John Bown
Origin UK Ltd
323 The Science Park
Milton Road
Cambridge
CB4 4WG
United Kingdom
mailto:john.bown at uk.origin-it.com
http://www.psynet.net/hippy
2. Re: Newby with a Ctrl-C problem
Welcome to the list-server, and yes I can help you out.
Its from library.doc in your euphoria\doc directory
Ralf
--[check_break]--
Syntax: include file.e
i = check_break()
Description: Return the number of times that control-c or control-break have
been pressed since the last call to check_break(), or since the
beginning of the program if this is the first call.
Comments: This is useful after you have called allow_break(0) which
prevents control-c or control-break from terminating your
program. You can use check_break() to find out if the user
has pressed one of these keys. You might then perform some
action
such as a graceful shutdown of your program.
Neither control-c nor control-break will be returned as input
characters when you read the keyboard. You can only detect
them by calling check_break().
Example:
k = get_key()
if check_break() then
temp = graphics_mode(-1)
puts(1, "Shutting down...")
save_all_user_data()
abort(1)
end if
See Also: allow_break, get_key
3. Re: Newby with a Ctrl-C problem
I also have some trouble with CTRL+Break. If i hit in a Euphoria program
launched from the editor in full screen, my computer will reboot without
notice. If i try to break out of it in a dos box, it'll give me a whole
bunch those notorious 'blue screens'
_________________
When it comes to programming languages, Euphoria is a cut above
matt1278 at juno.com Euphoria programmer
Webbers: <A HREF="mailto:prezsoft at juno.com">prezsoft at juno.com</A>,
president of SoftCo. All virus proggers should die horrible deaths™
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4. Re: Newby with a Ctrl-C problem
>I *must* be able to trap and handle Ctrl-C within my application -
>
>Using allow_break(TRUE) causes the app. to exit to MS-DOS as soon as
>Ctrl-C appears.
>
>Using allow_break(FALSE) prevents the exit to MS-DOS but get_key()
>doesn't return anything so I can't tell that Ctrl-C has turned up and
>handle it
>
>Anyone got any suggestions / solutions ?
Ralf's idea should work, but it may not work elegantly enough, depending
on the application. (You'll still see a ^C appear in your program.)
Another solution, used by David Cuny in EE, which comes with his TextGUI
toolkit, may work better, but the code is integrated into the toolkit, so
it will have to be extracted. Maybe David could explain further, or I
could dig out the code. (You should get the toolkit anyway, the editor is
more like DOS Edit, so you may feel more comfortable with it.)
The file is KEYS.E, but it has other stuff in it. (It uses some mouse
stuff, and other things from EE in it.) It has a routine in it that gets
the keys and returns CTRL-C safely.
I don't have time right now, but if you want, I can dig out the code for
getting the keys and wrap them up in a .E file, with docs and stuff later
on (Hopefully tonight, with Monday being the latest, depending on how
busy I am). (Or David, you could jump in and get the needed code and give
it to John sooner. 
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