I was in vi to edit one of the file through telnet from the client machine. All the sudden, my machine is crashed so I have to reboot. when I go in to try to edit this file again, it tell me that it give me an attention message and ask me to recovery this file since it's in the swap file now.

what is the command to recover this changes ???
I did try: vim -r filename but it said command not found. what is the command to clear the swap file. I don't really care if I lose my previous changes as long as I don't see this warning message again.

thanks