I was recently doing a code challenge for a job interview that required me to strip out all nonalphabetic characters. "Ah! I should use Regular Expressions for this!" I thought in triumph, impressed that I even knew what regular expressions were. That fleeting moment of glory faded once I decided to brush up on regular expressions and landed on the encouragingly-named Regular Expressions Cheatsheet. I had no idea how to use it!
So, for people like me, here is a Cheatsheet for the Regular Expressions Cheatsheet, Part III: POSIX
Okay, bear with me. POSIX means Portable Operating System Interface for uniX. It's just a different flavor of regex syntax that uses the following format:
foo is a descriptive term like
upper for "Upper case letters" or
Onto Part IV!