Question

Retrieve program randomAccess.cpp and the data file proverb.txt from the Lab 14 folder. The code
is as follows:
#include <iostream>
#include <fstream>
#include <cctype>
using namespace std;
327
int main()
{
fstream inFile("proverb.txt", ios::in);
long offset;
char ch;
char more;
do
{
// Fill in the code to write to the screen
// the current read position (with label)
cout << "Enter an offset from the current read position: ";
cin >> offset;
// Fill in the code to move the read position "offset" bytes
// from the current read position.
// Fill in the code to get one byte of information from the file
// and place it in the variable "ch".
cout << "The character read is " << ch << endl;
cout << "If you would like to input another offset enter a Y"
<< endl;
cin >> more;
// Fill in the code to clear the eof flag.
} while (toupper(more) == 'Y');
inFile.close();
return 0;
}
Exercise 1: Fill in the code as indicated by the comments in bold. The file proverb.txt contains the
following information:
Now Is The Time fOr All GoOd Men to come to the aid of their Family
Sample Run:
The read position is currently at byte 0
Enter an offset from the current read position: 4
The character read is I
If you would like to input another offset enter a Y
y
The read position is currently at byte 5
Enter an offset from the current read position: 2
The character read is T
If you would like to input another offset enter a Y
y
328
The read position is currently at byte 8
Enter an offset from the current read position: 6
The character read is e
If you would like to input another offset enter a Y
y
The read position is currently at byte 15
Enter an offset from the current read position: 44
The character read is r
If you would like to input another offset enter a Y
y
The read position is currently at byte 60
Enter an offset from the current read position: 8
The character read is r
If you would like to input another offset enter a Y
N
Exercise 2: Why do you think that the character printed at the last run was another 4? What
wouldyou have to do to get a different letter after the position is beyond the eof marker?
Exercise 3: Change the program so that the read position is calculated from the end of the file. What
type of offsets would you need to enter to get characters from the proverb? Do several sample runs
with different numbers to test your program.

Answer 1

/******************************************************************************

* Programe to read a file and write the content of input file into another file

*******************************************************************************/

#include<iostream>

#include<fstream>

#include<cstdlib>

using namespace std;

/* Function prototype */

void get_stream(ifstream& in_s,ofstream& out_s);

/* Definition of main function */

int main(){

char c;

//Declaration of the stream of type input and output

ifstream in_s;

ofstream out_s;

//Function call

get_stream(in_s,out_s);

while(!in_s.eof()){

in_s.get(c); //read all characters of input file one by one

out_s.put(c); //write all characters of input file one by one into output file

}

in_s.close(); //closing the input file

out_s.close(); //closing the output file

return 0;

}

void get_stream(ifstream& in_s,ofstream& out_s){

char input_file[15];

char output_file[15];

cout<<"Enter the name of the input file:";

cin>>input_file;

cout<<"Enter the name of the output file:";

cin>>output_file;

in_s.open(input_file);

if(in_s.fail())

{

cout<<"Unable to open input file "<<input_file<<endl;

exit(EXIT_FAILURE);

}

out_s.open(output_file);

if(out_s.fail())

{

cout<<"Unable to open output file "<<input_file<<endl;

exit(EXIT_FAILURE);

}

return;

}

@ubuntu:~/progra g+ Lab9B.cpp aubuntu:~/program$ ./a.out Enter the name of the input file:act9B.txt Enter the name of the output file:out9B.txt sam@ubuntu:-/programş cat act9B.txt o'er the Land of the free and the hore of the brave. o thus be it ever when freemen shall stand Between their lov'd home and the war's desolation! Blest with vict'ry and peace may the heav'n rescued land Praise the power that hath made and preserv'd us a nation! Then conquer we must, when our cause it is just, And this be our motto - "In God is our trust," And the star-spangled banner in triumph shall wave o'er the land of the free and the hone of the brave. ubuntu:~/programs cat out9B.txt o'er the land of the free and the home of the brave. o thus be it ever when freemen shall stand Between their lov'd home and the war's desolation! Blest with vict'ry and peace may the heav'n rescued land Praise the power that hath made and preserv'd us a nation! Then conquer we must, when our cause it is just, And this be our motto- "In God is our trust," And the star-spangled banner in triumph shall wave 0'er the land of the free and the hone of the brave. ubuntu:-/programs