This tutorial is intended to folks who are new to world of Linux. Like Command prompt in Windows, Linux have terminal where you can enter commands for your basic to advanced task. Terminal in Linux is very powerful tool. In this article we will be discussing some very basic commands and then forming a shell script with those commands.
You can open up Terminal from menu of your Linux Disrto. You can press
Alt+F2 and type
gnome-terminal to open up terminal. Now we will discuss some of the commands one by one.
cd <dir name> This command is used for changing the directory.
pwd This command prints working directory.
mkdir <dir name> This command is used for creating a directory
ls To list the file and directories inside a directory.
touch <file name> To create an empty file.
echo Hi This command will print Hi on terminal.
rmdir <dir name> Removes an empty directory.
rm <file name> Removes a file or directory.
These are some of basic commands which you will need to get started. There are a lot of many more commands which we come across while moving ahead with Linux. That we will discuss when we come around. Now we will move toward writing a script. A script is basically a file in which all commands are stored. It can reduce your effort of typing same commands again and again if you have to do same task lot many times. But if we talk about actual power of script it is far more powerful than above mentioned. It can perform looping, decision making and much more.
In this article we are discussing script as a basic bunch of commands. In forthcoming articles we will discuss more aspects of shell programming. Lets start. Open up terminal. Type
and enter following commands. Instead of
vi you can use your favorite text editor.
echo This is my first Shell Script echo $USER mkdir ./temp echo temp directory is created touch textfile.txt echo textfile.txt is created. mkdir ./temp/doc ./temp/doc/music ./temp/doc/pics echo doc dir is created. echo Displaying created Directory struct tree ./temp rm –rf ./temp/doc echo Now removing doc dir struct echo New dir tree tree ./temp rm -rf ./temp echo temp dir is removed
After entering all the commands press
:wq to save and quit from
vi. After creating shell script we need to change its permissions to make it executable. For doing so type
chmod +x ./my_first_script.sh
on terminal. Now we can execute this script by typing its path on terminal. If you are currently in the same directory where the script is, then type
to execute the script. If everything goes as mentioned here you should be presented with following output on terminal.
I have already explained much of the commands used in this script. In second line
$USER is a system variable. The command
echo is printing value of the variable. We can also use variables in our scripts. Variable names are preceded by
$. The command
tree presents directory structure in tree form. Note that
tree command may not be available as default in some distributions of Linux. All other commands used in script are already explained.