protoent - Protocol Names

The protoent structure defines the protocol-name mapping used with getprotobyname(3SOCKET), getprotobynumber(3SOCKET), and getprotoent(3SOCKET):

struct protoent {
   char     *p_name;          /* official protocol name */
   char     **p_aliases       /* alias list */
   int      p_proto;          /* protocol number */
};