Getting IPV4 address from a sockaddr structure

Question

How can I extract an IP address into a string? I can\'t find a reference that tells me how char sa_data[14] is encoded.

Answer 1

You can use getnameinfo for Windows and for Linux.

Assuming you have a good (i.e. it's members have appropriate values) sockaddr* called pSockaddr:

char clienthost[NI_MAXHOST];  //The clienthost will hold the IP address.
char clientservice[NI_MAXSERV];
int theErrorCode = getnameinfo(pSockaddr, sizeof(*pSockaddr), clienthost, sizeof(clienthost), clientservice, sizeof(clientservice), NI_NUMERICHOST|NI_NUMERICSERV);

if( theErrorCode != 0 )
{
    //There was an error.
    cout << gai_strerror(e1) << endl;
}else{
    //Print the info.
    cout << "The ip address is = " << clienthost << endl;
    cout << "The clientservice = " << clientservice << endl;
}