print  $#{[$lines =~ /aaa(.*?)bbb(.*?)ccc\s*dddd/gsi]} + 1 . "\n";  


##</code><code>##

$lines = "aaa
 xxxxxxx
 bbb
    ccc
dddd";


##</code><code>##

$lines = "
aaa
 xxxxxxx
 bbb
    ccc
dddd
aaa
    xxxxxxxxxxxxxxxxxxxxx
    xxxxxxx
  bbb
    xxxxxxxxxxxxxxxxxxxxx
    xxxx
    xx
ccc
dddd";


##</code><code>##

$lines = "
aaa
 xxxxxxx
 bbb
    ccc
dddd
aaa
    xxxxxxxxxxxxxxxxxxxxx
    xxxxxxx
  bbb
    xxxxxxxxxxxxxxxxxxxxx
    xxxx
    xx
ccc
dddd";

print  $#{[$lines =~ /aaa.*?bbb.*?ccc\s*dddd/gsi]} + 1 . "\n";