Some unknown linux commands

In this article I am going to tell you about some unknown Linux commands related to echo.You will typing those commands on Linux terminal.A terminal is basically the CMD of any Linux.You must know how to operate any Operating System through its terminal.In this tutorial I will be using Kali Linux.
So lets begin with very first command.
1 ) Type the following command on terminal.It will show all the files beginning with D in that directory.

root@kali:~#   echo D*

2 ) The following command can be used to perform arithmetic operations with the help of echo.

root@kali:~#  echo $((2+5))

root@kali:~#  cd echo $(((5*2)*3))

3 ) This command will show all the files and folders between "usr" and "share".You can type any folder name in your command.

root@kali:~#  echo /usr/*/share

4 ) There is an another way to perform arithmetic operations.

root@kali:~#  echo "2+5" | bc

Here bc stands for bash calculator.
So that was all about echo and Linux.Stay tuned for more articles.Leave a comment for any query.