I made a vanilla minecraft server and I made a redstone clock attached to a command block with /testfor that detects players. Can I change the /testfor from detecting players to detecting certain words in the chat? For example if warp was found in the chat, that would trigger the comparator next to the command block and trigger another command block with /tp @p x y z.(This is equivilant to "warping" someone somewhere)
No, this is not possible. This is due to the fact that commands cannot detect things like chat. If you want to detect chat, you could use Bukkit. There are many Bukkit plugins that allow you to detect players entering commands into chat and processing them. An example will be here. The good part about Bukkit is that vanilla, non-modded clients can connect without any problems. However, bukkit was taken down due to a DMCA request. An alternertive would be making your own plugin with Canarymod, which has similar functionality as Bukkit. Do note that it it is not as popular.