Privileges
sudo command – run command as root
sudo su – open a root shell
sudo su user – open a shell as user
sudo -k – forget sudo passwords
gksudo command – visual sudo dialog (GNOME)
kdesudo command – visual sudo dialog (KDE)
sudo visudo – edit /etc/sudoers
gksudo nautilus – root file manager (GNOME)
kdesudo konqueror – root file manager (KDE)
passwd – change your password
Display
sudo /etc/init.d/gdm restart – restart X (GNOME)
sudo /etc/init.d/kdm restart – restart X (KDE)
(file) /etc/X11/xorg.conf – display configuration
sudo dpkg-reconfigure -phigh xserver-xorg – reset X configuration
Ctrl+Alt+Bksp – restart X display if frozen
Ctrl+Alt+FN – switch to tty N
Ctrl+Alt+F7 – switch back to X display
This command will usually tell you the vendor and model of your graphic card
list
lspci
lspci -v
lspci -v | less
System Services
start service – start job service (Upstart)
stop service – stop job service (Upstart)
status service – check if service is running (Upstart)
/etc/init.d/service start – start service (SysV)
/etc/init.d/service stop – stop service (SysV)
/etc/init.d/service status – check service (SysV)
/etc/init.d/service restart – restart service (SysV)
runlevel – get current runlevel
Package Management
apt-get update – refresh available updates
apt-get upgrade – upgrade all packages
apt-get dist-upgrade – upgrade Ubuntu version
apt-get install pkg – install pkg
apt-get remove pkg – uninstall pkg
apt-get autoremove – remove obsolete packages
apt-get -f install – try to fix broken packages
dpkg –configure -a – try to fix broken packages
dpkg -i pkg.deb – install file pkg.deb
(file) /etc/apt/sources.list – APT repository list
Network
ifconfig – show network information
iwconfig – show wireless information
sudo iwlist scan – scan for wireless networks
sudo /etc/init.d/networking restart – reset network
(file) /etc/network/interfaces – manual configuration
ifup interface – bring interface online
ifdown interface – disable interface
Special Packages
ubuntu-desktop – standard Ubuntu environment
kubuntu-desktop – KDE desktop
xubuntu-desktop – XFCE desktop
ubuntu-minimal – core Ubuntu utilities
ubuntu-standard – standard Ubuntu utilities
ubuntu-restricted-extras – non-free, but useful
kubuntu-restricted-extras – KDE of the above
xubuntu-restricted-extras – XFCE of the above
build-essential – packages used to compile programs
linux-image-generic – latest generic kernel image
linux-headers-generic – latest build headers
Firewall
ufw enable – turn on the firewall
ufw disable – turn off the firewall
ufw default allow – allow all connections by default
ufw default deny – drop all connections by default
ufw status – current status and rules
ufw allow port – allow traffic on port
ufw deny port – block port
ufw deny from ip – block ip adress
Application Names
nautilus – file manager (GNOME)
dolphin – file manager (KDE)
konqueror – web browser/filemanager (KDE)
kate – text editor (KDE)
gedit – text editor (GNOME)
System
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
Moving around in the file system
pwd “Print working directory” – show what dir you’re in.
ls -List the contents of a dir.
ls -l -List the contents of a dir and show additional info of the files.
ls -a -List all files, including hidden files.
cd -Change directory.
cd .. -Go to the parent directory.
Manipulating files and directories
cp -Copy a file.
cp -i -Copy a file and ask before overwriting.
cp -r -Copy a directory with its contents.
mv -Move or rename a file.
mv -i -Move or rename a file and ask before overwriting.
rm -Remove a file.
rm -r -Remove a directory with its contents.
rm -i -Ask before removing a file. Good to use with the -r option.
mkdir -Make a directory.
rmdir -Remove an empty directory.
zipping/taring
tar -cvzf mytar.tar.gz sourcefilesordir – creates a new tar file, verbose options on, runs it through gnuzip,f is the filename
tar -xvf mytar.tar.gz destination – extracts a tar file (this example is compressed with gzip), verbosely, f is the filename
gzip fileordir – compresses a file with gzip.
gunzip file.gz – decompresses a file with gzip.
NB gzip only compresses files, it doesn’t collect them into a single file like a tarball does.
More Commands
Arrow Up: scrolls and edits the command history, press enter to activate.
Shift+pgup: scrolls terminal output up
Shift+pgdown: scrolls terminal output down
CTRL-ALT+DEL reboots the system
Shutdown -h now turns the system off
CTRL C kills the current process
CTRL S Stops the tranfer to the terminal
CTRL Q Resumes the transfer to the terminal
CTRL Z Puts the current process in the background.
hostname – Shows the host name of the system you are on
whoami Displays your login name
date – Displays what your machine thinks the date is
who – Shows who is logged into the machine
rwho-a -Shows all users logged into the server network
finger
last – Show the last users logged into the machine
uptime – Shows the systems uptime
PS – Shows the current user processes
PS -A – Shows all process on the system
uname -A -Displays all info on your host.
free -Shows the free memory in KB
df -h -Shows the disk space details
cat/proc/cpuinfo -Shows the CPU information
cat/proc/filesystems -Shows the file system information in use
cat/etc/printcap -Shows if any printers are hooked up
lsmod -Shows the kernel modules loaded
