Let's take a brand new computer purchased from a computer center.
It consists of
1. A monitor (To view the output or any movies :) )
2. A keyboard and a mouse (To provide inputs)
3. CPU and some other devices.
If we go deep into CPU, it contains a processor, RAM, Hard Disk, etc
Overall, it is a bunch of semi conductor devices electrically connected.
If we power-on the machine, it doesn't display anything yet.
Because, even though they are electrically connected.We need to provide the instructions to these circuit devices on how to interact among them.
This can be handled by a system software called as Operating System.
It takes care of interacting with the Hardware and provide an interface to the end user on how to use them.
60% of the Operating System code is Kernel, which is the program that is executed first when OS is running.And the remaining is the libraries, applications, interfaces either command or graphical based.Any application or program which needs to use any Hardware device should go through Kernel.
When an application requires a Hardware access or execution, it will be changed to kernel mode from user mode of execution to have access to Hardware. This process is done using software interrupt/exception(SWI).
To have the user an interface to execute or use any system utilities or launch any applications, there should be an option to interact with the Operating System. This is provided using the concept of Shell.
In Windows OS, this is handled using Powershell or CMD.exe,etc
In Linux, we have the concept of Shell and the entry point is named as Terminal.
Shell is an environment which acts as an interface betwen the Unix systm and user.
It gathers inputs from user and executes programs.When execution is completed,it displays the output of program.
In the Shell, we can have inbuilt commands, external files, OS Libraries.
These are called as utilities, through which we will tell exactly what is the instruction to execute to the shell.
We will execute them from Shell only but acts as a wrapper over shell.
Like copy is an utility we run on Shell to copy some files.
Some are provided by OS itself and we can create ourselves also.
There are different types of Shells supported by many flavors of Linux Operating System.Like Borne,Korn,etc
5 most frequently used ones are listed here Ref
As Linux is mostly used using terminal windows , we will show the commands which we will use most frequently in our day to day tasks.
As GUI mode, is not necessary to explain more.
It consists of
1. A monitor (To view the output or any movies :) )
2. A keyboard and a mouse (To provide inputs)
3. CPU and some other devices.
If we go deep into CPU, it contains a processor, RAM, Hard Disk, etc
Overall, it is a bunch of semi conductor devices electrically connected.
If we power-on the machine, it doesn't display anything yet.
Because, even though they are electrically connected.We need to provide the instructions to these circuit devices on how to interact among them.
This can be handled by a system software called as Operating System.
It takes care of interacting with the Hardware and provide an interface to the end user on how to use them.
60% of the Operating System code is Kernel, which is the program that is executed first when OS is running.And the remaining is the libraries, applications, interfaces either command or graphical based.Any application or program which needs to use any Hardware device should go through Kernel.
When an application requires a Hardware access or execution, it will be changed to kernel mode from user mode of execution to have access to Hardware. This process is done using software interrupt/exception(SWI).
To have the user an interface to execute or use any system utilities or launch any applications, there should be an option to interact with the Operating System. This is provided using the concept of Shell.
In Windows OS, this is handled using Powershell or CMD.exe,etc
In Linux, we have the concept of Shell and the entry point is named as Terminal.
Shell is an environment which acts as an interface betwen the Unix systm and user.
It gathers inputs from user and executes programs.When execution is completed,it displays the output of program.
In the Shell, we can have inbuilt commands, external files, OS Libraries.
These are called as utilities, through which we will tell exactly what is the instruction to execute to the shell.
We will execute them from Shell only but acts as a wrapper over shell.
Like copy is an utility we run on Shell to copy some files.
Some are provided by OS itself and we can create ourselves also.
There are different types of Shells supported by many flavors of Linux Operating System.Like Borne,Korn,etc
5 most frequently used ones are listed here Ref
As Linux is mostly used using terminal windows , we will show the commands which we will use most frequently in our day to day tasks.
As GUI mode, is not necessary to explain more.
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