Wiley-World.of.Warcraft.Programming.A.Guide.and.Reference.for.Creating.WoW.Addons

Chapter 2 ■ Exploring Lua Basics 19The rest of the error message is called a stack traceback, which tells youwhere the error occurred. This will be useful when you begin calling functionsfrom other functions.Using History to Make ChangesDepending on the Lua interpreter you are using, you may be able to viewthe recent command-line history (the last few commands you’ve given theinterpreter) by pressing the Up and Down arrow keys. Test this now bypressing the Up arrow key on your keyboard while in your Lua interpreter.(This always works in WowLua, but may not work correctly if you are usinga standalone version of Lua.)If it worked correctly, you should see the last line you typed (prnit(“HelloAzeroth!“)) and your cursor should be at the end of the line. If it didn’t work,you may instead see something similar to the following:> ˆ [[AThat simply means your specific interpreter doesn’t handle history.Although you may find this inconvenient at times, it certainly shouldn’thamper your capability to run through the examples correctly.Quitting the InterpreterWhen you are done running code in the interpreter, in most cases, you cansimply close the window. However, if you started the interpreter from acommand line and want to return to it, you can use one of the followingmethods, depending on your operating system.Microsoft WindowsOn a Microsoft Windows system, Lua can be closed by pressing Ctrl+Z. Thisinserts the following into your interpreter:> ˆ ZIn Windows this inserts a special character that means end-of-file, and itcauses the interpreter to quit. You can also press Ctrl+C to outright kill yoursession.Mac OS XMac OS X is a UNIX-based system, so the end-of-file character is differentfrom that of the Windows systems. At your prompt, press Ctrl+D toinsertthe end-of-file character and end the session immediately. You can also useCtrl+C to kill the session.