Cheat Sheet

Sometimes there are just handy things you need to know without understanding the whole world of GNU/Linux:

What version of the linux kernel am I using? (Note: this is specifically the kernel version, not the version of your distribution or any of the other programs you are running). 
type this in the terminal:

dmesg | grep Linux

How do I set a static IP address for my ethernet card?
The best way to learn how to do such things is to read the manual for ifconfig (man ifconfig), but the short answer is something like this:

ifconfig eth0 IP1 netmask IP2
route add default gw IP3

Where you replace the values IP1, IP2, and IP3 above, where IP1 is the static IP address, IP2 is the netmask (usually 255.255.255.0), and IP3 is the gateway IP address

What version of this software am I using?
sometime you can type a -v or --version after the application name in the terminal. For example if you want to know what version of MuSE you have installed, type:

muse -v

What username am I logged in as?
So, you want to know who you are, merely type:

whoami

What command do I use to change file permissions?

This is some serious business. You'll want to read the manual for the programm called chmod that controls file permissions. Run man chmod. 

what command do I use to mount external drives

External drives, USB keys, network filesystems, and other devices and drives will usually be recognized by your computer when you plug them in. However, if for some reason they do not, or you want to take matters into your own hand, you can use the mount command.  We suggest reading carefully the manual for mount (type 'man mount'). 

How do I shutdown my computer
Try either of these two options:

halt

shutdown now

my computer has started in GNU/Linux but I just see a big terminal window and its kinda scary looking
you haven't logged in... log in with your username and password, if you log in and don't see some fancy GUI then type :

startx

or

gdm

What do I do if I have accidentally deleted an important file using 'rm'
Promise yourself you will never ever do that again, back everything up and never logon as root.

If I have logged in under a username but i want to do something as the root user, how can I do that?
Use the commands su or sudo. Check the manual pages.

What time is it?
Try typing date in the command line

What month is it?
Try typing cal into the terminal

What modules are loaded?
Try typing lsmod

What system processes, software, etc., is running on my computer.
Try the ps command

I think someone knows my login password, how do I change it?
Try this command (or looking this command up in the man pages):

passwd