DB<39> $_ = "AAATTTAGTTCTTAAGGCTGACATCGGTTTACGTCAGCGTTACCCCCCAAGTTATTGGGGACTTT";

  DB<40> push @substr, $1 while /((\w)\2+)/g

  DB<41> @sorted = sort { length($b) <=> length($a) } @substr

  DB<42> x @sorted
0  'CCCCCC'
1  'GGGG'
2  'AAA'
3  'TTT'
4  'TTT'
5  'TTT'
6  'TT'
7  'TT'
8  'AA'
9  'GG'
10  'GG'
11  'TT'
12  'AA'
13  'TT'
14  'TT'
  DB<43>

##</code><code>##

  DB<43> print join "\n", sort { length($b)<=>length($a) } @substr
CCCCCC
GGGG
AAA
TTT
TTT
TTT
TT
TT
AA
GG
GG
TT
AA
TT
TT
  DB<44>