my @row = ('col1 : line1
col1 : line2',
'col2 : line1',
'col3 : line1',
'col4 : line1',
'col5:line1
col5:line2',
'coll6 : line1
coll6 : line2
coll6 : line3
coll6 : line4'
);

while ( join('',@row) ) {
        for(my $i=0;$i<=$#row;$i++) {
                my @a = split (/\n/,$row[$i]);
                my $s = shift(@a);
                print  ($s? $s . '|' : '|');
                $row[$i] = join("\n",@a);
        }
        print "\n";
}