套接字write（）函数的问题

Question

I am having issues getting the arguments of write() for sockets working properly. I built my own write() wrapper to accept std::string or char * . The code is below, as well as the compiler error, what silly mistake am I making that i can't seem to see properly? Ty

ftp.cpp:136:50: error: cannot convert 'std::basic_string<_CharT, _Traits, 
_Alloc>::length<char, std::char_traits<char>, std::allocator<char> >' from type 
'std::basic_string<char>::size_type (std::basic_string<char>::)()const {aka long unsigned 
int (std::basic_string<char>::)()const}' to type 'size_t {aka long unsigned int}'



int FTP::_write(std::string data)
{
    if (data != "")
    {
        int n = write(sockfd, data.c_str(), data.length); // this line is what the compiler is complaining about
        log->write("Write: " + data);
        if (n < 1)
            throw new FTPException(100, "Failed to write.");
    }
    else
    {
        int n = write(sockfd, buffer, strlen(buffer) + 1);
        log->write("Write: " + std::string(buffer));
        if (n < 1) 
            throw new FTPException(100, "Failed to write.");
    }
    return 1;
}

Answer 1

You need this line

int n = write(sockfd, data.c_str(), data.length);

to read

int n = write(sockfd, data.c_str(), data.length());