QLocalSocket Class

The QLocalSocket class provides a local socket. More...

Header:	#include <QLocalSocket>
qmake:	QT += network
Since:	Qt 4.4
Inherits:	QIODevice

This class was introduced in Qt 4.4.

List of all members, including inherited members

Public Types

enum	LocalSocketError { ConnectionRefusedError, PeerClosedError, ServerNotFoundError, SocketAccessError, SocketResourceError, …, UnknownSocketError }
enum	LocalSocketState { UnconnectedState, ConnectingState, ConnectedState, ClosingState }

Detailed Description

On Windows this is a named pipe and on Unix this is a local domain socket.

If an error occurs, error() returns the type of error, and errorString() can be called to get a human readable description of what happened.

Although QLocalSocket is designed for use with an event loop, it's possible to use it without one. In that case, you must use waitForConnected(), waitForReadyRead(), waitForBytesWritten(), and waitForDisconnected() which blocks until the operation is complete or the timeout expires.

See also QLocalServer.

Member Type Documentation

enum QLocalSocket::LocalSocketError

The LocalServerError enumeration represents the errors that can occur. The most recent error can be retrieved through a call to QLocalSocket::error().

Constant	Value	Description
`QLocalSocket::ConnectionRefusedError`	`QAbstractSocket::ConnectionRefusedError`	The connection was refused by the peer (or timed out).
`QLocalSocket::PeerClosedError`	`QAbstractSocket::RemoteHostClosedError`	The remote socket closed the connection. Note that the client socket (i.e., this socket) will be closed after the remote close notification has been sent.
`QLocalSocket::ServerNotFoundError`	`QAbstractSocket::HostNotFoundError`	The local socket name was not found.
`QLocalSocket::SocketAccessError`	`QAbstractSocket::SocketAccessError`	The socket operation failed because the application lacked the required privileges.
`QLocalSocket::SocketResourceError`	`QAbstractSocket::SocketResourceError`	The local system ran out of resources (e.g., too many sockets).
`QLocalSocket::SocketTimeoutError`	`QAbstractSocket::SocketTimeoutError`	The socket operation timed out.
`QLocalSocket::DatagramTooLargeError`	`QAbstractSocket::DatagramTooLargeError`	The datagram was larger than the operating system's limit (which can be as low as 8192 bytes).
`QLocalSocket::ConnectionError`	`QAbstractSocket::NetworkError`	An error occurred with the connection.
`QLocalSocket::UnsupportedSocketOperationError`	`QAbstractSocket::UnsupportedSocketOperationError`	The requested socket operation is not supported by the local operating system.
`QLocalSocket::OperationError`	`QAbstractSocket::OperationError`	An operation was attempted while the socket was in a state that did not permit it.
`QLocalSocket::UnknownSocketError`	`QAbstractSocket::UnknownSocketError`	An unidentified error occurred.

enum QLocalSocket::LocalSocketState

This enum describes the different states in which a socket can be.

Constant	Value	Description
`QLocalSocket::UnconnectedState`	`QAbstractSocket::UnconnectedState`	The socket is not connected.
`QLocalSocket::ConnectingState`	`QAbstractSocket::ConnectingState`	The socket has started establishing a connection.
`QLocalSocket::ConnectedState`	`QAbstractSocket::ConnectedState`	A connection is established.
`QLocalSocket::ClosingState`	`QAbstractSocket::ClosingState`	The socket is about to close (data may still be waiting to be written).

See also QLocalSocket::state().