I chuckled after I looked back over the op and realized what Chervil was talking about. Hint: What's wrong with your title ;)
>and what semicolon
The one that is missing from the end of line 8.
I don't think that is what he meant. The system call (on line 8) will return an int, not an std::string (thus result should be of type int). The original return statement you had was correct (return 0;).