<p>#include <stdio.h></p><p>#include <stdlib.h></p><p>//Function prototypes</p><p>void displayFile();</p><p>//Main function</p><p>int main()</p><p>{</p><p>char userName[30], password[30];</p><p>char ch;</p><p>//Two file pointers</p><p>FILE *file1, *file2, *outFile;</p><p>//Opening files in read mode</p><p>file1 = fopen("usernames.txt", "r");</p><p>file2 = fopen("passwords.txt", "r");</p><p>//Opening file in write mode</p><p>outFile =