Introduction to Unix

Uplatz provides this Unix tutorial to introduce you to the concepts of Unix and Linux operating systems.

Unix is an Operating System which is truly the base of all Operating Systems like Ubuntu, Solaris, POSIX, etc. Unix has been a popular OS for more than two decades because of its multi-user, multi-tasking environment, stability, portability and powerful networking capabilities.

 

The UNIX operating system is made up of three parts; the kernel, the shell and the programs.

1) The Kernel - The kernel of UNIX is the hub of the operating system: it allocates time and memory to programs and handles the filestore and communications in response to system calls.

2) The shell - The shell acts as an interface between the user and the kernel. When a user logs in, the login program checks the username and password, and then starts another program called the shell. The shell is a command line interpreter (CLI). It interprets the commands the user types in and arranges for them to be carried out. The commands are themselves programs: when they terminate, the shell gives the user another prompt. The bash shell has certain features to help the user inputting commands.

3) Commands and Utilities − There are various commands and utilities which you can make use of in your day to day activities. cp, mv, cat and grep, etc. are few examples of commands and utilities. There are over 250 standard commands plus numerous others provided through 3rd party software. All the commands come along with various options.

 

Everything in Unix is either a file or a process. A process is an executing program identified by a unique PID (process identifier). A file is a collection of data. They are created by users using text editors, running compilers etc. All the files are grouped together in the directory structure. The file-system is arranged in a hierarchical structure, like an inverted tree. The top of the hierarchy is traditionally called root.

Linux is also an operating system - very much like UNIX - that has become very popular over the last several years.

 

In the complete Unix training course, the delegates will learn:  Creating, copying, renaming, moving and deleting files and directories, Using the shell's redirection and pipe facilities, Editing text files using the vi editor, Setting and changing access permissions on files, Monitoring and controlling their own processes, Using the basic file and text searching utilities including regular expressions (regex), Customising their own login environment, Writing simple scripts to enhance basic command output, Using the various shell quoting mechanisms appropriately, Manipulating shell variables and user-defined variables in scripts, Implementing conditional execution facilities, Using the shell's built-in loop constructs where appropriate, Writing scripts to trap user interrupts, User defined Functions, Developing menu-driven shell scripts.