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print message if user does nothing for x seconds?

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Ben Thomas

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Nov 11, 2006, 2:16:08 PM11/11/06
to
Hi all,

Only just started using ruby so this may be really simple to do, but
here goes:

I'm trying to write a program that asks a user to enter their sex using
"gets" but if the user doesn't type anything for about 5 seconds I want
to print a message, like "Please enter something..." then go back to the
gets prompt. I've tried using the "sleep x" method but it doesn't seem
to work because once gets has been initiated it gets stuck there until
something is entered.

Oh I don't have to use gets, but this is the only method of input I'm
aware of at the moment

Hope this makes sense,
Ben

Hal Fulton

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Nov 11, 2006, 2:21:34 PM11/11/06
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This is tricky on Windows... what platform are you on?

Hal

Ben Thomas

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Nov 11, 2006, 2:29:01 PM11/11/06
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Windows... D'oh!

Is there any better ways to get input from the user that'd make is easier?

ara.t....@noaa.gov

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Nov 11, 2006, 3:07:28 PM11/11/06
to


if you're on windows give up now. otherwise try this:

harp:~ > cat a.rb
require 'timeout'

def prompt question, opts = {}
timeout = Integer(opts['timeout'] || opts[:timeout] || 42)
max = Integer(opts['max'] || opts[:max] || 42)
default = opts['default'] || opts[:default]
prod = (opts['prod'] || opts[:prod] || 'hey! wake up!').to_s

answer = default
prompt = "\r#{ question }: "
prod = "\r#{ prod }"

if prompt.size > prod.size
prod += (' ' * (prompt.size - prod.size))
end
if prod.size > prompt.size
prompt += (' ' * (prod.size - prompt.size))
end

max.times{
begin
print prompt
STDOUT.flush
Timeout::timeout(timeout){ answer = gets }
break
rescue Timeout::Error
print prod
STDOUT.flush
sleep 2
end
}

answer
end

answer = prompt 'the question', 'timeout' => 5, 'max' => 2

p 'answer' => answer


-a
--
my religion is very simple. my religion is kindness. -- the dalai lama

David Vallner

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Nov 11, 2006, 3:10:59 PM11/11/06
to

Read the data in a thread, or use nonblocking io (currently crude at
best, with only eventmachine to help as a project that shown up on my
radar - and that seems to be oriented towards networking)

Also, what you describe there is a very rude thing to do to your user,
basically you're accusing them of having no attention span and the
program is attention-seeking to compensate.

David Vallner

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Ben Thomas

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Nov 11, 2006, 3:33:57 PM11/11/06
to

Yeah, I'd never even think of doing it normally, it was just put in a
small program specification for uni. It's not an assignment or anything
so I'll probably just leave that part out if it's hard to implement.

The part of the specification was:

3. Keep the program running until the user shouts “BYE”. If, while
the program is running, nothing is happening Grandma should shout
“WHAT? CAT GOT YOUR TONGUE? SPEAK UP, I SAY!"


I'll just leave the "cat got your tongue" part out for now. Managed to
keep the program running until the user shouts "BYE" easy enough, just
the second part causing problems.

Thanks for the help.

Gabriele Marrone

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Nov 11, 2006, 3:35:12 PM11/11/06
to

Nice! May I suggest adding an optional validation block?
I hope you don't mind if I slightly modify your code:


def prompt question, opts = {}, &validation


timeout = Integer(opts['timeout'] || opts[:timeout] || 42)
max = Integer(opts['max'] || opts[:max] || 42)
default = opts['default'] || opts[:default]
prod = (opts['prod'] || opts[:prod] || 'hey! wake up!').to_s

invalid = (opts['invalid'] || opts[:invalid] || 'try again').to_s

answer = default
prompt = "\r#{ question }: "
prod = "\r#{ prod }"

if prompt.size > prod.size
prod += (' ' * (prompt.size - prod.size))
end
if prod.size > prompt.size
prompt += (' ' * (prod.size - prompt.size))
end

max.times{
begin
print prompt
STDOUT.flush
Timeout::timeout(timeout){ answer = gets }

if validation && !validation.call(answer)
answer = default
puts invalid
else
break
end


rescue Timeout::Error
print prod
STDOUT.flush
sleep 2
end
}

answer
end


answer = prompt('the question', 'timeout' => 5, 'max' => 2) { |s| s
== "valid input\n" }

--
Gabriele Marrone

Ben Thomas

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Nov 11, 2006, 3:40:21 PM11/11/06
to

Thanks for the reply. Unfortunately I am on windows.

Hal Fulton

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Nov 11, 2006, 3:47:00 PM11/11/06
to
Ben Thomas wrote:
>
> Thanks for the reply. Unfortunately I am on windows.
>

Actually I think this should partially work on Windows.

As I recall, I found that as long as the user typed
*nothing*, timeout was possible. But if the user
typed a character or more and just didn't finish, it
wouldn't time out.


Hal


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