These commands work on both client and server.
logfile
Usage: logfile [filename]
This command will begin writing a log of all console events to an external file.
Note: No file extension will be applied to the log unless done by the user. For instance, if you wanted to log to an output file named "newlog.txt", you would use the command as logfile newlog.txt.
stoplog
Usage: stoplog
This command will stop logging if there is currently a logfile being written.