Grooming Classroomnotes 10/Mar/2023

Operating Systems and How Applications Work

To run any application OS creates a Process.
Each Process gets cpu share, Memory and Disk and Network based on the process which you are running.
Each Process will have unique identifier (id)

Every Command is a computer program/Executable
Commands have two types of arguments by the way you pass the values
- positional argument: This argument is processed based on position
  cp 1.txt 2.txt cp 3.txt 1.txt
- keyword argument: In this case around the argument you will pass a name or a keyword. Generally linux style name arguments have two hyphens -- if you pass the keyword an single - if you pass the shorthand notation
  ping -c 2 google.com ping google.com -c 2 ping --count 2 google.com
Every command line generally has a documentation which we call as manual. Lets start using manual to figure out what commands can do
When you type any command every operating system has a location where the folders to be searched are configured. This is done by a variable (Environmental variable) called as PATH

When a user is created in any system a directory called as home directory will be created for the user where he has full permissions
Tilde ~ on a terminal represents home directory

Windows:  C:\Users\<username>
Linux:  /home/<username>
Mac: /Users/<username>

In command line dot . represents current directory and double dots .. represent parent directory