support for multiple files + modified argparse options

[0rovan]

I have added support for input from multiple log files to your script and I'd be happy if you want to pull from me. However you may not like changes to argument parser based mainly on my personal preferences .

[syedaali]

readlines() will read the entire file in memory, you can easily overwhelm the memory of a system by doing this. I was using 'for line in file' which reads one line at a time. Thoughts?

[0rovan]

In practice apache logs are relatively small - https://httpd.apache.org/docs/2.2/logs.html#rotation
If someone wants to do something stupid all it takes then is to craft file with one line long enough to overwhelm memory when readline() function is used.
So, imho, the real solution here would be to read by character with read(1) or check for file size before the file read.