use strict;

my $seq1 = 'aabcdefg';
my $seq2 = 'aabcdefgabcde';
in_sequence($seq1);
in_sequence($seq1);

sub in_sequence
{
    my $str = shift;  # fetch the string value
    my $ok = 1;       # set private variable $ok = 1
    print "outside regexp, ", \$ok, "\n";
	$str =~ m/(.)(.)(??{ print "inside regexp, ", \$ok, "\n"; 0 })/;
    return $ok;
}