Yeah, the question is far to vague. The answer might be as short as: 
while (<$LOG_FILE>) {
     $error_count++ if /error/i;
}

[download]
if assuming you know how to do the rest and understand how to use the above. Or it might need much more information if you don't know or understand these things. And we don't know whether you know these things.

In reply to Re: Report filtering by Laurent_R
in thread Report filtering by rahul02

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