Don't enclose variables in doublequotes!

s/(\${\w+})/find_value_for_var("$1")/e is better written as s/(\${\w+})/find_value_for_var($1)/e! While in this case the quotes cannot "break" the script, it forces Perl to make an additional copy of the matched string each time the regexp matches.

I wish "$var" trigered a warning. While I admit there are valid reasons to do that I bet they make up at most 0.01% of the times it's used. :-(

Edit by castaway: Closed small tag in signature