The Firstday Sessions at Uki,

 

What is an Operating System?

So, to work on your computer, you need an Operating System(OS). In fact, you are using one as you read this very article on your laptop/computer. 

The computer program that allocates the system resources and coordinates all the details of the computer’s internals, such as scheduling tasks and controlling peripherals, is called an Operating System. 

Now, you might have used popular Operating Systems such as Windows or iOS. In this article, we’re talking about one in particular – the Linux Operating System!

Introduction to the Linux OS

Linux is a family of open source operating system. The Linux OS now offer millions of programs/applications and Linux software to choose from, most of them are free. Hundreds of different Linux versions, also known as distributions, are available today. Each is typically tailored for specific target systems, such as servers,desktops,mobile devices.Distrubtions may be read-to-source code that you must compile locally during initial installation. Community developed distributions include Debian,Slackware and Gentoo.Commercial distributions include Fedora by Redhat,OpenSUSE from SUSE and Ubunthu  from Canonical.Linux is completely different from other OS in ways more than a few .It is an open source OS which gives a great advantage to the programmers in the form of options in programs.

Linux Commands

            Basic Linux Commands

Linux provides a Command Line Interface (CLI)  to communicate with the OS.

1.pwd- Displays the current working directory of the terminal.

2.clear- Clears the terminal screen. Contents will not actually be deleted in this case, only scrolled down.  [Ctrl+L]

3.cp- Copies files and directories

4.mv- Moves files and directories from one  directory to another.

5.rm- Removes files from a directory. Does not remove directories. Once removed, the contents of a files cannot be recovered.

6.grep- Searches for a particular word/string in the text file.[Ctrl+F]

7.ls- List all the contents in the current work directory.

8.cd- Used to change the current working directory of the user.

9.mkdir- Creates a new directory.

10.chmod- Used to change the access permissions of files and directories.

The permissions associated with each digit is as follows.

Number	read	write	execute
0	–	–	–
1	–	–	yes
2	–	yes	–
3	–	yes	yes
4	yes	–	–
5	yes	–	yes
6	yes	yes	–
7	yes	yes	yes

To change directory permissions in Linux, use the following:

chmod +rwx filename to add permissions.
chmod -rwx directory name to remove permissions.
chmod +x filename to allow executable permissions.
chmod -wx filename to take out write and executable permissions.

Note that “r” is for read, “w” is for write, and “x” is for execute. 

This only changes the permissions for the owner of the file.

to be continued....