This document provides a summary of common commands and configuration files used in Ubuntu systems for privileges, networking, display, package management, applications, services, and system recovery. It includes commands for sudo access, configuring networking and wireless settings, starting and stopping services, installing and removing packages, checking the system version, and rebooting the system through keyboard shortcuts. Configuration files like /etc/network/interfaces and /etc/X11/xorg.conf are also listed.

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