C++文件操作

string  getFileContext(const string& filename){    string str;    str.clear();    char buf[1024];    char *p;    p = buf;    memset(buf, 0, 1024);    ifstream in;    in.open(filename);    while ((*p = in.get()) != EOF)    {        p++;    }    cout << "Buf" << endl;    puts(buf);    str += buf;    cout << str << endl;    in.close();    return str;}