As one of the popular operating systems in the market, UNIX was developed by the Bell Laboratories by AT&T. It is considered as a highly dependable operating system due to its stable nature. UNIX started out as a multi-tasking, multiple user operating systems and eventually evolved along with other networking technologies, thus making the operating system one of the primary support on communication and Internet networking. Even though there are various versions of UNIX such as HP/UX by Hewlett-Packard, System V by IBM and Berkeley Standard Distribution (BSD), they are distinctively similar when it comes to their functionality and design.
Features of the UNIX operating system
It is importance to be familiar with the features of UNIX before moving on to the basic commands. Both portability and multitasking are essential features of the operating system. Multiple users can readily access the system while at the same time run multiple processes or programs in just a single system. With the high-level language used by UNIX, it is easy to modify and transfer to other machines. It simply means that you can easily alter the language codes based on the requirements of the new hardware on your computer. Another important feature of UNIX is the kernel and shell which both execute your commands. With the UNIX shell, it is where you communicate with your system. The UNIX shell is basically the program that provides and displays all your prompts. Along with the kernel, it executes all the commands you entered. For those who are not technically-inclined, the shell offers customization options. Lastly, all the functions in UNIX typically involve a file or a process. These processes are executions of programs while the files are the collections of data that you created. The files can include the programming instructions for a directory or for the system. The operating system utilizes a categorized filing structure that starts with a root directory that is designated by the forward slash (/).
Basic UNIX concepts that you should be familiar with
It is a standard that every user has a distinct username. Once you will login into the system, you are taken to a HOME directory which is part of the disk space that was set aside for you. The moment you login to a UNIX system, the main interface to the system is known as the UNIX SHELL. You have to take note that this is the program the presents you with the dollar sign ($) prompt. Obviously, this prompt indicates that the shell is ready to accept the commands that you will type.
The UNIX commands
The UNIX commands are basically series of characters that are entered using your keyboard. If you want to run a particular command, all you have to do is to type it and press the ENTER key. You have to bear in mind that UNIX extends the power of the commands by utilizing special switches or flags. These switches are considered the most compelling features of UNIX commands. The switches are typically headed with a dash (-) and comes first before any filenames on the command line. The UNIX operating system is case sensitive unlike with the DOS command line. Almost all the command names as well as the command line switches are in lowercase characters. Do not forget that the UNIX commands can also be grouped together in order to come up with a powerful command which has the capability called the I/O redirection (> for outputting to a file and < to get input from a file) and piping which utilizes |in order to feed the output of a single command as an input to the next.
Essential UNIX commands
These are some of the commands that can help you get started with the UNIX operating system. You might be already familiar with some of these commands if you have used other operating systems.
- ls will lists files in current directory
- mkdir will make a directory
- rmdir will remove directory
- cp will copy file
- rm will remove
- mv will move
UNIX commands useful in managing your account
- passwd will change the password
- grep will find files that contain a particular word
- ps will list all running processes
- kill will kill processes with the ID entered
- gzip will compress a file