(a) Program Explanation Function readBytes: The name of the function is readBytes(). This function has threearguments. The first argument is a file object name of fstream type. The second argument is of long type used for the offset of the character to be read. The third argument is of integer type and stores the number of characters to be read. When the function is called, this function opens the file object that is passed as argument andread and display the number of characters form the given starting position from the file. The function definition is: // including essential header files #include <iostream> #include <fstream> #include <string> #include <cstdlib> // using standard namespace usingnamespace std; // function to read the number of characters from a file void readBytes (fstream&file, long offset, int numChar) { // variable declaration char ch; long last; // check for successful open if (file.fail()) { // display file not open cout<<"\nThe file was not successfully opened"<<"\n Please check that the file currently exists"<<endl; exit(1); } // move to the end of the file file.seekg(0L, ios::end); // save the offset of the last character last = file.tellg(); //loop to read the character from the file for (int i = offset; i < (offset+numChar); i++) { // when position is beyond the file if(i >= last) { // display an error message cout<<endl<<"Error! The position is beyond the file."; // exit the function exit (1); } //set the position file.seekg(i, ios::beg); // read the character from the file ch = file.get(); // display the character cout<< ch; } } Explanation: In the above program, the function named readBytes () is used to read and display the number of characters from the given starting position from the file. This function open the file using the file object name. The function named fail()returns false when the file is not found. When the file found read the data from the files. Using the function named seekg () move the cursor to the end of the file... (b) Program Plan Intro To modify the function named readBytes () created in the exercise 6a.