Write a program that encrypts the alphabetic letters in a file using the Vigenere cipher. Your program will take two command line parameters containing the names of the file storing the encryption key and the file to be encrypted. The program must generate output to the console (terminal) screen as specified below.

1) Write a section of code or function that reads only the upper and lower case letters in the input file into an char array of size 512, storing only the appropriate lowercase letters in the character array.

2) Write a section of code or function that takes as input the array from section 1 and the encryption key and produces an array of ciphertext storing only lowercase letters.

3) Write a section of code or function that takes as input the array storing the ciphertext and outputs it to the screen in the format specified. Additional functions or code will be needed to echo the input key and plaintext files.