ALGORITHM: find_common
    INPUT: list of files (file_list)
    DECLARE: hash of IDs (id_hash)
    CALL: get_data WITH references to file_list and id_hash
    CALL: get_common WITH reference to id_hash

##</code><code>##

#!/usr/bin/perl -w
use strict;

my $first = 0;

my ($keynum, @stans, @procs, @resultBucket) = (undef, (),(),());

my $usefulRegex = qr~ID([^\:]+):(.*)$~;

while (<DATA>){
   ++$first && next if (m/^FILE/ || (m/^\s*$/));
   if ($first >= 2) {
        #processing the data
	if(m/$usefulRegex/){
             $procs[$1] = $2;
	     if ($stans[$1] ne $procs[$1]) {
                  print qq~$1 lines are different\n~;
             }
        }
   } else {
        #storing the core for comparison
        if(m/$usefulRegex/){
             $stans[$1] = $2;  
        }
   }
   print;

}

print qq~first: $first\n~;

__DATA__
FILE1
ID1:6qq5_A|14~~6qq5_B|14~~6qq6_A|14~~6qq6_B|14~~6t6v_A|14
ID2:7d5p_A|14~~7d5q_A|14

FILE2
ID1:6qq5_A|15~~6qq5_B|15~~6qq6_A|14~~6qq6_B|15~~6t6v_A|14
ID2:7d5p_A|14~~7d5q_A|12
                 

##</code><code>##

 perl -e '$aline = qq~foo1: fie fo fum~; my ($aid,$rec) = split /:/,$aline; $aid=~s/^[a-z]+//; print qq~$aid...$rec\n~;'                                                                                  
1... fie fo fum