reading until the end of file in C++

Question

I\'m trying to read till the end of a file for a phonebook app that im converting from C to C++. When I print the the results from the file i get this:

johnn         


        

Answer 1

1. Don't use !eof(). It checks whether the last read failure was due to reaching the end of the file. It does not predict the future.

2. Don't use malloc in C++. If you do, check the return value for errors!

3. Don't use operator>> for char *. There's no size check so that's just asking for buffer overflows.

4. The '\n' check on buffer is useless. operator>> for strings stops at whitespace.

5. You're blindly strcpying a string of unknown length into temp.home of size 20. That's another buffer overflow.

6. ... I kind of stopped reading there. If you want to read stuff from a file but stop on eof/error, you can do something like this:

.

string a, b, c;
while (true) {
    if (!(in >> a)) break;
    if (!(in >> b)) break;
    if (!(in >> c)) break;
    do_stuff_with(a, b, c);
}