Displays time of last system boot Show Sample Output

To get your effective user: whoami Show Sample Output

Prints current runlevel and system start time. On older systems it also shows the last init state. Pretty useful on remote systems, pretty useless on local ones :) Show Sample Output

Logs all users out except root. I changed the grep to use a regexp in case a user's username contained the word root.

It's only to logout all other user's except "root"

Only to logout all users except root

Finds the login id of the user that owns the console. I use it to reset my touchpad after resume from suspend in /etc/pm/sleep.d/s99local

Will print the host associated with the current stdin. This is useful to set the DOIT_SERVER for the doit remote execution agent ( http://www.chiark.greenend.org.uk/~sgtatham/doit/ ) export DOIT_HOST=$(who -m | sed 's/.*(\(.*\)).*/\1/') Note that SSH_CLIENT variable can be lost if you use su or sudo (if set to reset vars) Show Sample Output

http://www.thegeekstuff.com/2009/03/4-ways-to-identify-who-is-logged-in-on-your-linux-system/

In my work environment, we log onto the servers as our user ('user', in the sample ouput), and 'sudo su - root' to other accounts. This trick allows us to return the account name we logged in as -- and not the account name we currently are ('root', in this example). Using this trick, you can build other commands: Set your CVSROOT env variable to your account name: CVSROOT=$(who am i | awk '{print $1}')@cvs.server.example.com:/cvsroot SCP a file to another server: scp file.txt $(who am i | awk '{print $1}')@some.other.server.com:. This works out great in my environment, as we can include this in our documentation and make the comands more easy to copy/paste for different users, and not have to set all sorts of variables, or modify the docs for each user. whoami gives you the name of the user you currently are, not the user you logged on originally as. who gives you a listing of every single person logged onto the server. who am i gives you the name of the user you logged on as, and not who you changed to with su. Look at the following scenario: whoami user su - # whoami root # who am i user pts/51 2009-02-13 10:24 (:0.0) whoami != who am i Show Sample Output