Today I want to show you some examples of parameter expansion or parameter substitution as it is called in Bash. I've already used parameter expansion a few times in this series but now I want to show you how it works (at least some basics, I don't want to report the whole manual here).
Have you ever stumbled upon this: you write a shell script which works with variables containing spaces and suddenly the whole script breaks? This is because most shells automatically split strings on spaces. This is some ancient behavior and in most cases it is just a pain in the ass.
Welcome to the first article of this year's Advent calendar series. The last Advent calendar was extremely successful so I thought it would be a good idea to continue this.
The topic for the Advent calendar series 2011 is “24 Outstanding ZSH Gems” because the Z Shell is my absolute favorite shell. There's nothing ZSH can't do except the dishes. In my opinion it's much more powerful than any other shell out there. If you are not a ZSH user (yet?), you're still very welcome to enjoy this series as well. Maybe then you'll make the switch. And if not: some features also work similarly in Bash, although they might be not so comfortable there. 
Now let's begin with programmable renaming of files or batch renaming. That sounds very abstract, but let me show you what I mean.
