network-2.4.2.3: Low-level networking interface

Copyright | (c) Bryan O'Sullivan 2009
License | BSD-style
Maintainer | bos@serpentine.com
Stability | experimental
Portability | POSIX, GHC
Safe Haskell | None
Language | Haskell98

Network.Socket.ByteString.Lazy

Contents

- Send data to a socket
- Receive data from a socket

Description

This module provides access to the BSD socket interface. This module is generally more efficient than the `String` based network functions in `Socket`. For detailed documentation, consult your favorite POSIX socket reference. All functions communicate failures by converting the error number to `IOError`.

This module is made to be imported with `Socket` like so:

    import Network.Socket hiding (send, sendTo, recv, recvFrom)
    import Network.Socket.ByteString.Lazy
    import Prelude hiding (getContents)

Synopsis

- send :: Socket -> ByteString -> IO Int64
- sendAll :: Socket -> ByteString -> IO ()
- getContents :: Socket -> IO ByteString
- recv :: Socket -> Int64 -> IO ByteString

# Send data to a socket

send

Arguments

:: Socket | Connected socket
-> ByteString | Data to send
-> IO Int64 | Number of bytes sent

Send data to the socket. The socket must be in a connected state. Returns the number of bytes sent. Applications are responsible for ensuring that all data has been sent.

Because a lazily generated `ByteString` may be arbitrarily long, this function caps the amount it will attempt to send at 4MB. This number is large (so it should not penalize performance on fast networks), but not outrageously so (to avoid demanding lazily computed data unnecessarily early). Before being sent, the lazy `ByteString` will be converted to a list of strict `ByteString`s with `toChunks`; at most 1024 chunks will be sent. Unix only.

sendAll

Arguments

:: Socket | Connected socket
-> ByteString | Data to send
-> IO () |

Send data to the socket. The socket must be in a connected state. This function continues to send data until either all data has been sent or an error occurs. If there is an error, an exception is raised, and there is no way to determine how much data was sent. Unix only.

# Receive data from a socket

getContents

Arguments

:: Socket | Connected socket
-> IO ByteString | Data received

Receive data from the socket. The socket must be in a connected state. Data is received on demand, in chunks; each chunk will be sized to reflect the amount of data received by individual `recv` calls.

All remaining data from the socket is consumed. When there is no more data to be received, the receiving side of the socket is shut down. If there is an error and an exception is thrown, the socket is not shut down.

recv

Arguments

:: Socket | Connected socket
-> Int64 | Maximum number of bytes to receive
-> IO ByteString | Data received

Receive data from the socket. The socket must be in a connected state. This function may return fewer bytes than specified. If the received data is longer than the specified length, it may be discarded depending on the type of socket. This function may block until a message arrives.

If there is no more data to be received, returns an empty `ByteString`.