Oneliners

find . -iname "*.pm" -o -iname "*.pl" | while read i; do grep "use " $i; grep "require " $i; done | perl -e 'while (<STDIN>) { $x->{$2}=1 if /^\s*(use|require)\s+(\S+).*;/}; print join("\n",map {"  * ".$_ }sort keys %$x),"\n"'