Further Reading

Forensics

The greater CTF topic of today has been forensics. It's probably one of the vastest and most diverse topics out there, because it doesn't really fit into many patterns. You can read more about forensics here.

Regular Expressions

Regular expressions are like globs on steroids. They provide a huge step-up in terms of expressiveness. As expected, they're also more difficult to understand.

By default, grep actually matches regular expressions, not just raw strings. find can also look fore files matching regular expressions, by using the -regex and -regextype parameters (yes, there are multiple regular expression syntaxes).

A good point from which to start learning how to use regular expressions are these resources:

• https://medium.com/factory-mind/regex-tutorial-a-simple-cheatsheet-by-examples-649dc1c3f285
• https://regexone.com/

For testing your regular expressions before using them, this website is king.

Once you've got the hang of regular expressions, test your skills in the regular expression Crossword. Yes, such a thing really does exist and it's as crazy as you might think. Give it a try!

Moreover, most programming languages have libraries for regular expressions. Python can do so, too. Take a look at its regular expression module.