Adding use strict; at the beginning of your script will catch all sorts of typos and bad things because it forces you to declare everything you use. eg:

my $temp = 'hello';

print $tmp;
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would print nothing, because $tmp is not defined. Of course, you meant to print $temp, but if you don't use strict, this error will go unnoticed by Perl and you may miss it. This example is trivial, but if you had 100 lines of code, it could easily occur!

cLive ;-)