Creates a new TCP socket of the specified address family.


#include <prio.h> 

PRFileDesc* PR_OpenTCPSocket(PRIntn af);


The function has the following parameters:

The address family of the new TCP socket. Can be PR_AF_INET (IPv4), PR_AF_INET6 (IPv6), or PR_AF_LOCAL (Unix domain, supported on POSIX systems only).


The function returns one of the following values:

  • Upon successful completion, a pointer to the PRFileDesc object created for the newly opened TCP socket.
  • If the creation of a new TCP socket failed, NULL.


TCP (Transmission Control Protocol) is a connection-oriented, reliable byte-stream protocol of the TCP/IP protocol suite. PR_OpenTCPSocket creates a new TCP socket of the address family af. A TCP connection is established by a passive socket (the server) accepting a connection setup request from an active socket (the client). Typically, the server binds its socket to a well-known port with PR_Bind, calls PR_Listen to start listening for connection setup requests, and calls PR_Accept to accept a connection. The client makes a connection request using PR_Connect.

After a connection is established, the client and server may send and receive data between each other. To receive data, one can call PR_Read or PR_Recv. To send data, one can call PR_Write, PR_Writev, PR_Send, or PR_TransmitFile. PR_AcceptRead is suitable for use by the server to accept a new client connection and read the client's first request in one function call.

A TCP connection can be shut down by PR_Shutdown, and the sockets should be closed by PR_Close.

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 Contributors to this page: teoli, Waldo, Wtchang
 Last updated by: teoli,