While Ubuntu is known for its ease of use, some basic Linux command lines will come in handy for installing software, traversing directories and handling files. For starters, you can directly enter Linux command lines using the Terminal program found under Applications, then Accessories. In the Terminal window, you should see username@computer_name followed by a dollar sign in the command prompt. The dollar sign indicates that the system is awaiting command line entries. Here is a lowdown of some menu options available in Terminal:
- Open Terminal: Opens a new terminal session in separate terminal windows.
- Open Tab: Opens a new terminal session in a separate tab.
- New Profile: lets you create a profile with different fonts, backgrounds and colours for each command line session.
- Profile Preferences: Edit existing profiles.
-Keyboard shortcuts: Assign shortcuts for terminal functions such as copy and paste command lines and opening new Terminal windows and tabs.
 

Check what the commands do by using the man (or manual) command. For example, type “man ls” for an explanation of the “ls” command that lists a folder’s contents. You can also add additional parameters for more granular control over the functions of each command line. These parameters are preceded by a dash. For example, keying in -F after the ls command will differentiate between the files and folders. You can also combine multiple parameters. Using the -a and -F parameters in the “ls” command will reveal all files and folders including hidden ones.

Traversing directories Navigate your folders with the cd or change directory command. In this example, the cd command takes you to the Desktop folder. Note that folder names are case-sensitive: aaron@aaron-laptop:~$ cd/home/aaron/Desktop

Installing programs Linux software packages using installer files downloaded from the Internet usually come in the RPM (Red Hat Package Manager) or DPKG (Debian Package Manager) formats. To install a program with a DPKG installer, type: sudo dpkg -i program_name To remove a pragram, type: sudo dpkg -r pragram_name If you change upon an RPM installer that you want to run on Ubuntu, you need to convert it to a DPKG installer using the Alien program in Uduntu. Type: alien -k program_name.rpm, then install the program using new DPKG installer.

Handling files To copy files from one directory to another, use the cp command. For example, to copy a file called screenshot.png from /home/aaron/Desktop to /home/aaron, type aaron@aaron-laptop:~/Desktop$ cp screenshot.png/home/aaron/ You can also rename the copied file in the destination folder by typing aaron@aaron-laptop:~/Desktop$ cp screenshot.png/home/aaron/screenshot2.png.

Run levels Linux uses the init program to control system boot processes and user modes through various “run levels”. In run level 1, for instance, Linux boots up in single-user mode with no networking support. In run level 2, you get a multi-user system with a graphical interface. By default, Ubuntu boots up to run level 2. You can change run levels in a Terminal window by issuing the following init commands: – init 0: shut down the system – init 1: single user mode with no networking – init 2: default for Debian Linux based distributions including Ubuntu with multi-user mode and graphical interface. – init 3: multi-user mode without graphical interface. – init 4: used for customized run level. – init 5: multi-user mode with graphical interface (used by most distributions). – init 6: reboots the system.

Tips & Trick Linux