So I downloaded the server file and stuff and I was messing around and totally screwed it up cuz i didnt know anything and got bored so I deleted it. Later I decieded to make a server again so I downloaded the server file again but it said IP already in use. [from the old server I made and deleted] So I looked in trash and there the old one was, but my computer didnt let me delete it because it was 'in use' but I havent used it in months... Please help I'm running a Mac.
I'm not sure about Macs, but on Windows, you can open the task manager and kill the craftbukkit process. Maybe check the Mac equivalent and see if it is still lingering? I usually get the IP already in use error when I start craftbukkit as a process and not from the .bat file.