Most likely, the error is in your loop or your loop condition.

I imagine that your loop looks something like:

my $user_id = <>; # the scanner sends keyboard input
my $person_timeout = time() + 30; # 30 seconds until we consider the s
+can done

while( time < $person_timeout and my $book_id = <> ) {
    $person_timeout = time() + 30; # 30 seconds until we consider the 
+scan done
    print "Person $user_id has checked out book $book_id\n";
}
[download]

In my toy example, the program will re-enter the loop and try to read from the scanner. Even if the timeout passes, it will still be waiting for the input.

Without knowing more about your program, your loop and how things are structured, I can't really give more concrete advice. Maybe you can show us a short example that reproduces your problem. The example should not be longer than 30 lines.

---

---

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.