Here are some useful and helpful commands which is generally used in day to day workings on the Linux system. Following commands were tested on the Ubuntu/Debian Linux.
To fix the broken packages
$ sudo apt-get install -f
Removing automatic installed packages
$ sudo apt-get autoremove
Check Gnome Shell version
$ gnome-shell --version
Current Kernel Version
uname -r
Compress PDF file using ghostscript
$ gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf
Open help and options info of a command
$ man <command>
Short help info of any command
$ <command> --help
Make ISO of A Directory
An ISO of a directory containing files and sub-directories can be made using this command.
mkisofs -o image.iso -R /path/to/folder/
Force Kill Application
Run following terminal command then click the application’s window to close it.
xkill
Logout without prompt
$ pkill -KILL -u $USER
Create an ISO image of CD/DVD
sudo cat /dev/sr0 > foo.iso