Cin C + +. getline reads one character

I’m using Xcode 4.5 and I have the following code in my program:

string str;
char strChar[5];
cin.getline(strChar, 5);
int i = atoi(str.basic_string::c_str());

When I start to try and enter a number, after the first number is pressed, the console will not accept any more input (other than the enter key, in which case the program just returns zero straight away). Obviously, I want to accept more than one character, how can I accomplish this?

Thanks for answering my question