Ubuntu Reference

Below I will give basic referene table comant line of Linux-based Ubuntu. Comant this line needs to be known by the linux lovers, especially the new users. Starting from the coment line on the network, displays, packages, firewalls, system services. Hopefully help guys!
Linux is number one!

Privileges	Network
sudo command – run command as root	ifconfig – show network information
sudo -s – open a root shell	iwconfig – show wireless information
sudo -s -u user – open a shell as user	sudo iwlist scan – scan for wireless networks
sudo -k – forget sudo passwords	sudo /etc/init.d/networking restart – reset network for manual configurations (file) /etc/network/interfaces – manual configuration
gksudo command – visual sudo dialog (GNOME)	ifup interface – bring interface online
kdesudo command – visual sudo dialog (KDE)	ifdown interface – disable interface
sudo visudo – edit /etc/sudoers
gksudo nautilus – root file manager (GNOME)	Special Packages
kdesudo konqueror – root file manager (KDE)	ubuntu-desktop – standard Ubuntu environment
passwd – change your password	kubuntu-desktop – KDE desktop
	xubuntu-desktop – XFCE desktop
Display	ubuntu-minimal – core Ubuntu utilities
sudo /etc/init.d/gdm restart – restart X and return to login (GNOME)	ubuntu-standard – standard Ubuntu utilities
sudo /etc/init.d/kdm restart – restart X and return to login (KDE) (file) /etc/X11/xorg.conf – display configuration	ubuntu-restricted-extras – non-free, but useful
sudo dexconf – reset xorg.conf configuration	kubuntu-restricted-extras – KDE of the above
Ctrl+Alt+Bksp – restart X display if frozen	xubuntu-restricted-extras – XFCE of the above
Ctrl+Alt+ N – switch to tty N	build-essential – packages used to compile programs
Ctrl+Alt+F7 – switch back to X display	linux-image-generic – latest generic kernel image
	linux-headers-generic – latest build headers
System Services¹
start service – start job service (Upstart)	Firewall¹
stop service – stop job service (Upstart)	ufw enable – turn on the firewall
status service – check if service is running (Upstart)	ufw disable – turn off the firewall
/etc/init.d/service start – start service (SysV)	ufw default allow – allow all connections b default
/etc/init.d/service stop – stop service (SysV)	ufw default deny – drop all connections b default
/etc/init.d/service status – check service (SysV)	ufw status – current status and rules
/etc/init.d/service restart – restart service (SysV)	ufw allow port – allow traffic on port
runlevel – get current runlevel	ufw deny port – block port
	ufw deny from ip – block ip adress
Package Management¹
apt-get update – refresh available updates	Application Names
apt-get upgrade – upgrade all packages	nautilus – file manager (GNOME)
apt-get dist-upgrade – upgrade with package replacements; upgrade Ubuntu version	dolphin – file manager (KDE)
apt-get install pkg – install pkg	konqueror – web browser (KDE)
apt-get purge pkg – uninstall pkg	kate – text editor (KDE)
apt-get autoremove – remove obsolete packages	gedit – text editor (GNOME)
apt-get -f install – try to fix broken packages
dpkg --configure -a – try to fix broken packages	System
dpkg -i pkg.deb – install file pkg.deb (file) /etc/apt/sources.list – APT repository list	Recovery - Type the phrase “REISUB” while holding down Alt and SysRq (PrintScrn) with about 1 second between each letter. Your system will reboot.
	lsb_release -a – get Ubuntu version
	uname -r – get kernel version
	uname -a – get all kernel information