getnameinfo

     getnameinfo - address-to-name translation in protocol-independent manner

       #include <sys/socket.h>
       #include <netdb.h>

       int getnameinfo(const struct sockaddr *sa, socklen_t salen,
                       char *host, size_t hostlen,
                       char *serv, size_t servlen, int flags);

       getnameinfo(): _POSIX_C_SOURCE >= 1 || _XOPEN_SOURCE || _POSIX_SOURCE

 it converts a
       socket address to a corresponding host and service, in a protocol-independent
       manner.