This sounds like a homework question (a question requiring a couple of concepts without an obvious real-world application). Don't be afraid to state that it is.

That being said, if I were to implement this, I would want a few items:

• A counter to store the remaining time (perhaps a global variable or a lexical variable or a Time::DurationTime::Interval or some other Interval object or some such; perlsyn for some background reading)
• A method to decrease the counter (see perlop and search for decrement)
• A method to display the counter in the correct format. (see printf as one option)
• A method to determine if I am at a 10 second mark (see perlop and search for modulo)
• A method to prompt a user for input (printf or Prompt might be useful)
• A method to compare strings (see perlop for the difference between eq/ne and ==/!= or perlretut for regular expression help)
• A method to break out of a loop (see perlsyn for last and next)

Show your work, be honest about the homework status, ask questions. Just like coursework, you tend to get more out of PerlMonks if you put more of yourself into it.

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.