UNIX

A telephone directory, teledir.txt, maintains records in the form name: number where number is of the form nnn-nnn-nnnn. Devise a shell script that accepts one or two arguments that could be: (i) the name or number. If it exists in the directory, then the line should be displayed (ii) both. The entry is displayed if it exists and is added if it doesnt exist in the file. Note that the number will always be entered as a 10-digit string, so youll have to use the script developed in Exercise 13.18 to perform both conversion and validation