How to create a bash script

   A shell script file should conventionally have an extension .sh

   The first line of your script file should be #!/bin/bash, this line actually tells
   the OS that the script is a bash script.

   A simple script file example

   open a script file say file1.sh with vi. vi file1.sh

   #!/bin/bash
   echo "Hello World, this is what I got in my home directory
   ls /home/subhroneel

   save the file and quit vi.

   set executable permission to file1.sh

   $chmod u+x file1.sh

   run the script just as written below

   $./file1.sh

   output is:  
   Hello World
   Listing of /home/subhroneel directory
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