As they already said, there's a Module to do this ... or several (TMTOWTDI) ... but there's also a really cute expression that's worth grokking-in-fullness, even if you should use the module instead, since it's a lovely example of s///g and s///e together.

From Effective Perl Programming (Hall with Schwartz, 0-201-41975-0 not linked to Fatbrain, please support your local meatspace bookstore),

  $_ = "a%5eb"; 
  s/%([0-9a-fA-F]{2})/pack("c",hex($1))/ge;
[download]

which also says only one paragraph later

  use URI::Escape;
  $_ = uri_unescape "a%5eb";
[download]

Both will result in $_ eq "a^b".

and Yes, it will handle "9%25EA" correctly, tranforming it to "9%EA" and not eating the output %. See s///g. (What's 9%EA? maybe fair share for 11-way split, less crumbs.)

-- Bill / n1vux