Write a bash script to comment code blocks in a bash source file. A bash comment is all characters from a # character (beginning a word) to the end of the line.

Conditions:

• The source file will contain only printing characters, spaces, and newlines.
• The source file will contain validbashcode. It is not necessary to check for invalid input.
• The source file may contain nested blocks.
• In the source file the keywords while until for case if done esac elif else fi 
  will be the first words on a line, will not be in comments, and will not be quoted.

Requirements:

• Read from standard input, write to standard output.
• At the end of any line containing while until for add the comment: # loop n 
  (n is a number, 1 for the first loop, 2 for the second loop, etc)
• At the end of any line containing done add the comment: # loop n 
  (n is the number corresponding to the matching while until for )
• At the end of any line containing if case add the comment: # selection n 
  (n is a number, 1 for the first selection, 2 for the second selection, etc)
• At the end of any line containing fi esac add the comment: # selection n 
  (n is the number corresponding to the matching if case )

Include all of the following:

• comments with your name, the date, and the assignment
• comments with instructions for using the program
• descriptive names and/or comments explaining variables & functions
• indentation of code blocks
• comments explaining any non-obvious control flow

Hints:

• work on the simplest cases first
• think about the structure of your data and logic before you write any code
• start with the smallest possible amount of code
• make sure your existing code works before adding new code
• add the smallest possible amount of new code, then test again
• output variable values, loop counts, etc. for debugging
• test your code with a variety of inputs