How do I set a script that it will run on start up in FreeBSD?

Question

I am using FreeBSD 9 and I want to make a script that will check if an Ethernet cable is connected, and if so, connects to it. I want to set it so that it runs whenever the machine starts up, or whenever I log in. I looked at my UNIX book (It is pretty outdated, and is for general UNIX, not specifically FreeBSD) and it says that I can use crontab, but I can only do this to make things run at certain times, not when it starts up. Can someone please tell me how I can get at this?

Answer 1

FreeBSD's cron understands the @reboot time directive, so you can indeed have cron execute your script at startup. Instead of the usual 5 time fields, your crontab entry might look like this:

@reboot /path/to/script

If you want also to run the check when you log in, add a call to the script in the file your shell executes upon login - this could be, depending on your shell, ~/.login, ~/.bash_login, etc.

Answer 2

Another solution for startup script would be /etc/rc.local.