If you are starting Firefox from a terminal window where you have specified the proxy settings, and you have the use system proxy settings option ticked, you will not need to set the proxy within Firefox. That is a very cool tip indeed.
If you need to set the proxy before using apt, you will not be successful when you type
sudo apt-get install foo. Type
sudo su - and then specify the required proxy settings so it will be picked up by apt.
I installed Ubuntu from the minimal installation ISO for Ubuntu 14.04 and I did not get the proper resolution for the virtual consoles and Xorg. I fixed this by editing the /etc/default/grub file and specifying the resolution there.
Uncomment this line and set the desired resolution. This fixed my issue.
Another way to run a command as the root user using
homer@ubuntu:~$ su-to-root -c ls About to execute ls. This command needs root privileges to be executed. Using sudo... Enter homer password at prompt. Desktop Documents Downloads
How to install kernel headers for your currently installed kernel. Using backticks makes this very easy, you may embed the output of a command into a one-liner.
homer@ubuntu:~$ sudo apt-get install linux-headers-`uname -r` Reading package lists... Done Building dependency tree Reading state information... Done linux-headers-3.13.0-32-generic is already the newest version. linux-headers-3.13.0-32-generic set to manually installed. 0 to upgrade, 0 to newly install, 0 to remove and 0 not to upgrade.
Another way to get a root shell using VIM and sudo.
sudo vim foo.txt to open a text file named foo.txt as the superuser.
now in command mode: type:
!/bin/sh and hit ENTER. This will give you a root prompt that you may use to enter and run any command that you wish. Very cool exploit indeed. I found this here: http://www.computersecuritystudent.com/UNIX/SUDO/lesson1/.
There is more information about sudo exploits here: http://www.vnsecurity.net/2012/02/exploiting-sudo-format-string-vunerability/.
There is another method here that uses less: http://www.computersecuritystudent.com/UNIX/SUDO/lesson2/.