foreach (split "\n", $web) {
    if (m/(log_id\=(\d*)\&.*?Label Defect)/m) {
        #... etc
    }
}

##</code><code>##

{
    open my $foo, '<', \$web or die $!;
    while (<$foo>) {
        if (m/(log_id\=(\d*)\&.*?Label Defect)/m) {
            #... etc
        }
    }
}