A shell script to manage your personal contact book which will keep record of your contact details. Follow the below instructions to write the shell script.

• Input: contacts.csv is the input file with fields fname (FirstName), lname (LastName), mobile (Mobile Number), Office (CompanyName).
• This contacts.csv will be updated after every insert, delete and edit. No command other than display all, or search and display should print anything on the terminal.
• No command other than display all, or search and display should print anything on the terminal.
• The output for ‘search and display’ and ‘display all’ should be coma separated words in the same sequence as the format of the csv.
• The commands should be as follows
  • Insert Contact
  • Edit Contact
  • Display all Contacts
  • Search and Display
  • Delete Contact

The system should run based on flag-based command line arguments. A flag –C would be used to first specify the command (which would be one of ‘insert’, ‘edit’, ’display’, ‘search’, ‘delete’) The flags for each command are as follows:

o -f for entering first name
o -l for entering last name
o -n for entering contact number
o -o for entering company name

o -k give the first name of the contact to be edited (assume no 2 contacts
have same first name)
o -f for entering updated first name
o -l for entering updated last name
o -n for entering updated contact number
o -o for entering updated company name

o -a to sort in ascending order of first name
o -d to sort in descending order of first name

o -c for entering the column on which it is to be searched (has to be one of
first name, last name or number)
o -v for the search value of that column

o -c for entering the column on which it is to be searched (has to be one of
first name, last name or number)
o -v for the search value of that column of the record to be deleted