Here's the list of tips

• 1) Lexical file handles: my $fh
• 2) 3 parameter form of open
• 3) Validate your data file to make sure each line has data.
• 4) Declare your variables inside the loop with my

open my $data_fh, 'data.txt' or die $!;
open my $log_fh, '>>', 'logfile.txt' or die $!;

while (<$data_fh>) {
    chomp;
    next if /^\s*$/;
    my ($domain, $IP) = split ',';
    if ($ip_obj->{src_ip} eq $IP){
        print $log_fh "$domain has been found";
    }
}
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