Write log when somebody attempt to load OS

Question

I'd like to write a log when somebody attempt to access my computer. (e.g. enter login and password, doesn't matter successfully or not). I use Arch Linux and CDM (console display manager).

ps: I have very strong suspicions that someone really do it, and at least, I'd like to know what time it happen.

Answer 1

The log should already exist. Try using the last command.

Login failures are normally logged by syslog to somewhere like /var/log/messages You can grep that file for login failures.