G'day rahul02,

This is an inappropriate way to ask a question here. You should know this from your last (and only other) post, "Perl Script for reading a mathematical expression", which contained just:

"i want to know the basic idea for writing a perl script which will read a mathematical expression from user, evaluate the result and print on the screen."

I suggest you read both "How do I post a question effectively?" and "How (Not) To Ask A Question".

"perlintro -- a brief introduction and overview of Perl" should provide the basics you need; follow the links provided for more detailed information on the topics of interest (e.g. Files and I/O).

Use Text::CSV (or one of its related modules) for your CSV work.

It is difficult suggesting the steps you need to take when we dont know if learning to program, learning Perl, and learning to use Google are steps that you have already taken, or not. Where do you want us to start? We might be able to focus our assistance better if you would show what you've tried,and explain what your own research has led you to understand.

while (<$LOG_FILE>) {
     $error_count++ if /error/i;
}
[download]

For inspiration take a look at Parsing Apache logs with Regex. Please see also Search_engine.

Regards, Karl

for each line in log file {
  detect an error
  count of whole errors ++;
}

print result in csv file
[download]

I think however that what you need to do is sit down and design your solution.

Take all that you know about what you want, then ask yourself "what do I not know?".

Research what you don't know, and use what you find.

When you run into something that you simply can't do... then go to the "how do I ask questions" pointed to by others previously and use that to frame the question up.

I think the problem your having is that you have not put in enough effort to know what questions you have.

You know you want to use Perl(or you would not have posted here), and you know you want .csv as output. What do you know about the log files? Are they local? Are they text files? Do you have access to them? etc...?

Hope that is helpful.