bash - UNIX systems coating. This is the shell of most GNU/Linux system distributions. Commands are written in text mode on the console and executed after approval.
You can also create line by line scripts or batch scripts.
who - who is currently logged into the system
pwd - displays the name of the current folder
ls - displays the contents of the current folder
clear - clears the console window
echo - displays text in the console
man - help, displays, among others, the syntax of the command
cal - displays the monthly calendar
exit - closes the console
shutdown - closes the system

mkdir - creates a new folder
cd - go to the home folder
cd\ - go to the root folder
cd.. - move to parent folder
touch - creating an empty file
rm - deleting of a file
rmdir - deleting a folder
mkdir - creating a new folder
cat - displaying the contents of a filebr>

ls > pol - entering the command "ls" into a file named "pol"
call >> pol- adding a command "cal" to a file named "pl"
more pol - calling up the commands contained in the "pol" file


- scripts can be written in any text editor, e.g. GEdit,
- commands should be typed each in a new line,
- ready to save the script on the disk in a file, e.g. under the name "script1",
- the script can be run in two ways:
   1) the command "source" e.g. source script1
   2) by changing the property of the file to executable (x)


  echo ”Enter I number”
  read a
  echo ”Enter II number”
  read b
  let s=$a+$b
  echo ” The sum is $s.”



  g++ program_name.cpp -o program_name


   fpc program_name.pas


   ./ program_name