Question

#include <iostream>
#include <string> 
#include <fstream>
using namespace std;
int main() {
char x[20];
cout << "enter something\n";
cin.getline(x,20);
ofstream o("d:/tester.txt");
//o.write( (char*)&x , sizeof(x) );
for(int i = 0 ; i<=19 ; i++ ) {
 o.put(x[i]);
}
}

I am not getting that output in the file the one which i enter during program . for eg. the output is 畳慨汩朠灵慴찀쳌쳌쳌 on writing suhail gupta.

What is the problem with the code ? Even when i use o.write( (char*)&x , sizeof(x) ); (the commented statement) i get the same output.

What is the reason?

Answer 1

Your program involves undefined behavior. The x array is not fully initialized and you read from the uninitialized indices. Besides, you always write 20 bytes, independent of what you read from the user.

I guess you use some text editor like Notepad. The latter has bugs when trying to guess the encoding. It appears that it guesses the file is UTF16 and displays 20/2 == 10 characters instead.

To solve the problem, store to the file exactly the number of characters entered by the user. Use std::string to make it easier.

Edit: The C++ way:

#include <iostream>
#include <string> 
#include <fstream>
using namespace std;
int main() {
    string x;
    cout << "enter something\n";
    getline(cin, x);
    ofstream o("d:/tester.txt");
    o << x;
}