WoW:Creating a slash command

Simple Example

Suppose you have:

function MyScript_Command(cmd)
  DEFAULT_CHAT_FRAME:AddMessage("Command: " .. cmd);
end

In your OnLoad function of your script, or in the .lua anyplace after the function is defined, put in the following:

SLASH_MYSCRIPT1 = "/myscript";
SLASH_MYSCRIPT2 = "/mys"; -- A shortcut or alias
SlashCmdList["MYSCRIPT"] = MyScript_Command;

The Details

SLASH_<CommandId><num> 
SlashCmdList["<CommandId>"] = <CodeToExecute>

Slash command parsing is done by the chat frame, and it works as follows.

• The key of each entry is the <CommandId>. It should be the unique name of your Addon.
• The parser then examines SLASH_<CommandId>1, SLASH_<CommandId>2, ... and so on, until it either finds a match, or gets a nil value (undefined) on the next SLASH_<CommandId><Number>.
• If there was a hit, then the function value of SlashCmdList["<CommandId>"] is invoked, with the rest of the command line as its single parameter

• Special 'built in' slash commands for chat are handled first.
• The chat handler then iterates over the contents of the global table SlashCmdList
• Otherwise, the next command is searched until a match is found or the list is exhausted.

Conventions

• Command ID's are generally all caps, with underscores if necessary.
• Pick a command ID that's going to be unique to your addon, a common convention is ADDONNAME_COMMANDNAME, or if you just have one, then ADDONNAME (Where ADDONNAME is the name of your addon).
• The actual SLASH_<CommandId><Number> values should be localizable if you plan on your addon being translated, but the command ID will remain the same.
• Be prudent about how many aliases you make for your command, and try and pick something that's unlikely to collide with someone else's.