socket - Sockets 2 Reference

Sockets 2 Reference

Home Index About

Custom Search

socket

The Windows Sockets socket function creates a socket which is bound to a specific service provider.

SOCKET socket (

int af,
int type,
int protocol
);

Parameters
af

[in] An address family specification.

type

[in] A type specification for the new socket.

protocol

[in] A particular protocol to be used with the socket which is specific to the indicated address family.

Remarks
The socket function causes a socket descriptor and any related resources to be allocated and bound to a specific transport service provider. Windows Sockets will utilize the first available service provider that supports the requested combination of address family, socket type and protocol parameters. Note that the socket created will have the overlapped attribute. Sockets without the overlapped attribute can only be created by using WSASocket.

Note The manifest constant AF_UNSPEC continues to be defined in the header file but its use is strongly discouraged, as this can cause ambiguity in interpreting the value of the protocol parameter.

The following are the only two type specifications supported for Windows Sockets 1.1:

Type	Explanation
SOCK_STREAM	Provides sequenced, reliable, two-way, connection-based byte streams with an out-of-band data transmission mechanism. Uses TCP for the Internet address family.
SOCK_DGRAM	Supports datagrams, which are connectionless, unreliable buffers of a fixed (typically small) maximum length. Uses UDP for the Internet address family.

In Windows Sockets 2, many new socket types will be introduced. However, since an application can dynamically discover the attributes of each available transport protocol through the WSAEnumProtocols function, the various socket types need not be called out in the API specification. Socket type definitions will appear in WINSOCK2.H which will be periodically updated as new socket types, address families and protocols are defined.

Connection-oriented sockets such as SOCK_STREAM provide full-duplex connections, and must be in a connected state before any data can be sent or received on it. A connection to another socket is created with a connect call. Once connected, data can be transferred using send and recv calls. When a session has been completed, a closesocket must be performed.

The communications protocols used to implement a reliable, connection-oriented socket ensure that data is not lost or duplicated. If data for which the peer protocol has buffer space cannot be successfully transmitted within a reasonable length of time, the connection is considered broken and subsequent calls will fail with the error code set to WSAETIMEDOUT.

Connectionless, message-oriented sockets allow sending and receiving of datagrams to and from arbitrary peers using sendto and recvfrom. If such a socket is connected to a specific peer, datagrams can be sent to that peer using send and can be received only from this peer using recv.

Support for sockets with type RAW is not required, but service providers are encourage to support raw sockets whenever it makes sense to do so.

Return Values
If no error occurs, socket returns a descriptor referencing the new socket. Otherwise, a value of INVALID_SOCKET is returned, and a specific error code can be retrieved by calling WSAGetLastError.

Error Codes

WSANOTINITIALISED	A successful WSAStartup must occur before using this function.
WSAENETDOWN	The network subsystem or the associated service provider has failed.
WSAEAFNOSUPPORT	The specified address family is not supported.
WSAEINPROGRESS	A blocking Windows Sockets 1.1 call is in progress, or the service provider is still processing a callback function.
WSAEMFILE	No more socket descriptors are available.
WSAENOBUFS	No buffer space is available. The socket cannot be created.
WSAEPROTONOSUPPORT	The specified protocol is not supported.
WSAEPROTOTYPE	The specified protocol is the wrong type for this socket.
WSAESOCKTNOSUPPORT	The specified socket type is not supported in this address family.

See Also
accept, bind, connect, getsockname, getsockopt, ioctlsocket, listen, recv, recvfrom, select, send, sendto, setsockopt, shutdown, WSASocket

Last news from Greatis Software

    Nostalgia .Net     .Net is powerful, but not all-powerful, so sometimes we need to use Win32 API for our .Net applications. It's simple enough with Platform Invoke if you have Win32 skill, but we do not always have time to dig the ancient documentation, declare the special types that are compatible with Win32, find the values of the Win32's constants and so on. Nostalgia .Net offers several simple-to-use classes, and components that will allow you to forget about the headache of Win32 and just use the power of Win32 in your application the same way as you use the native. Net classes. More »

Recommended software for developers

    Ultimate Pack     Component pack for Delphi and C++ Builder that contains runtime form designer, runtime object inspector, print suite and much more for the very special price. More »

    Form Designer .Net     Unique runtime form design solution that allows to edit any form in .Net WinForms application at runtime with full source codes for only 300 euro! More »

    Print Suite .Net     Print Suite .Net is a set of components for easy printing texts, images and grids from your WinForms applications. Full C# source codes are available More »

    Gradient Controls .Net     Gradient Controls .Net offers controls with gradient background feature. Labels, panels and so on... Full C# source codes are available More »

    Greatis iGrid     iGrid plots drawing grid right over your desktop, so you can use it everywhere, with any drawing application without any special plugins for different graphic editors. More »

All the contacts and projects

Dmitry Vasiliev (just.dmitry)

More Online Helps

Win32 Programmer's Reference
Win32 Multimedia Programmer's Reference
OLE Programmer's Reference
Microsoft Windows Pen API Programmer's Reference
Microsoft Windows Sockets 2 Reference
Microsoft Windows Telephony API (TAPI) Programmer's Reference
Unix Manual Pages

greatis just4fun network