Here's a snippet which creates an array of references to the desired values...

$l=0;
while($l<$#sorted)
{
   push @data_out_ref, \$sorted[$l] if substr($sorted[$l],0,7) ne subs
+tr($sorted[$l++ +1],0,7);
}
print "$$_\n" for @data_out_ref;
[download]

...and here's one which removes the elements from the original array...

for($l=0; $l<$#sorted; $l++)
{
 splice(@sorted, $l, 1) if substr($sorted[$l],0,7) eq substr($sorted[$
+l+1],0,7);
}
[download]