I don't know the answer to your question, but I noticed a bad practice. When including Perl source code that's not in a package, you should use do "filename.pl", not require "filename.pl", because it will fail in this scenerario:

package AAA;
require "111.pl";
longestLineLength(@a);  # Works.
package BBB;
require "111.pl";       # Does nothing. Already required.
longestLineLength(@a);  # ERROR.

-vs-

package AAA;
do "111.pl";            # Creates &AAA::longestLineLength
longestLineLength(@a);  # Works.
package BBB;
do "111.pl";            # Creates &BBB::longestLineLength
longestLineLength(@a);  # Works.
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Of course, it wouldn't hurt to put the extra line to make it into a module that you could require/use.