Converting Apache/Tomcat Access Logs to CSV

​ Woonsan Ko

​ 2012-07-11

Recently, I had to analyze the Apache / Tomcat access log files, and so I needed to convert the log files into CSV in order to have a chance to use other tools such as spreadsheet.
The conversion shouldn't be hard. I found some scripts (in PHP, AWK, Perl or Ruby) on the internet, but those didn't fit my needs quite well. I didn't want to lose any data such as http method, byte size sent in response, etc. Also, the CSV should contain spreadsheet friendly data format. For example, "2012-07-10 22:30:03" instead of "10/Jul/2012:22:30:03".
So, I ended up writing yet another one by myself. Why not? ;-)
Here's the link to the source:

• https://github.com/woonsan/accesslog2csv/blob/master/accesslog2csv.pl

The script can be executed like the following:

$ perl accesslog2csv.pl access_log_file > csv_output_file.csv

Or, you can redirect STDIN like the following examples:

$ perl accesslog2csv.pl < access_log_file > csv_output_file.csv

$ cat access_log_file | perl accesslog2csv.pl > csv_output_file.csv

Also, you can check invalid log lines by redirecting STDERR, too:

$ perl accesslog2csv.pl < access_log_file > csv_output_file.csv 2> invalid_log_lines.txt

Hope it helps somewhere! :-)