理解Unix Stream Socket

• Unix domain socket

  A Unix domain socket or IPC socket(inter-process communication socket) is a data communication endpoint for exchanging data between processes executing on the same host OS.

  Valid socket types in the UNIX domain are:

  • sock_stream : for a stream-oriented socket
  • sock_dgram : for a datagram-oriented socket
  • sock_seqpacket : for a sequenced-packet socket that is connection-oriented

• Communication endpoint

  A communication endpoint is a type of communication network node.

• Node(networking)

  In telecommunications networks, a node is either a redistribution point or a communication endpoint.

  The definition of a node depends on the network and protocol layer referred to.

• Network socket(stream socket)

  A network socket is a software structure within a network node of a computer network that serves as an endpoint for sending and recevicing data across the network.

  The structure and properties of a socket are defined by an application programming interface (API) for the networking architecture.

  Sockets are created only during the lifetime of a process of an application running in the node.

  A socket is externally identified to other hosts by its socket address, which is the triad of transport protocol, IP address, and port number.