Php/docs/function.socket-recvfrom

• PHP Manual
• Socket 函数
• Receives data from a socket whether or not it is connection-oriented

socket_recvfrom

(PHP 4 >= 4.1.0, PHP 5, PHP 7)

socket_recvfrom — Receives data from a socket whether or not it is connection-oriented

说明

socket_recvfrom ( resource $socket , string &$buf , int $len , int $flags , string &$name [, int &$port ] ) : int

The socket_recvfrom() function receives len bytes of data in buf from name on port port (if the socket is not of type AF_UNIX) using socket. socket_recvfrom() can be used to gather data from both connected and unconnected sockets. Additionally, one or more flags can be specified to modify the behaviour of the function.

The name and port must be passed by reference. If the socket is not connection-oriented, name will be set to the internet protocol address of the remote host or the path to the UNIX socket. If the socket is connection-oriented, name is null. Additionally, the port will contain the port of the remote host in the case of an unconnected AF_INET or AF_INET6 socket.

Note: 此函数可安全用于二进制对象。

参数

socket

The socket must be a socket resource previously created by socket_create().

buf

The data received will be fetched to the variable specified with buf.

len

Up to len bytes will be fetched from remote host.

flags

The value of flags can be any combination of the following flags, joined with the binary OR (|) operator.

Possible values for flags

Flag	Description
MSG_OOB	Process out-of-band data.
MSG_PEEK	Receive data from the beginning of the receive queue without removing it from the queue.
MSG_WAITALL	Block until at least len are received. However, if a signal is caught or the remote host disconnects, the function may return less data.
MSG_DONTWAIT	With this flag set, the function returns even if it would normally have blocked.

name

If the socket is of the type AF_UNIX type, name is the path to the file. Else, for unconnected sockets, name is the IP address of, the remote host, or null if the socket is connection-oriented.

port

This argument only applies to AF_INET and AF_INET6 sockets, and specifies the remote port from which the data is received. If the socket is connection-oriented, port will be null.

返回值

socket_recvfrom() returns the number of bytes received, or false if there was an error. The actual error code can be retrieved by calling socket_last_error(). This error code may be passed to socket_strerror() to get a textual explanation of the error.

范例

Example #1 socket_recvfrom() example

<?phperror_reporting(E_ALL | E_STRICT);$socket = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);socket_bind($socket, '127.0.0.1', 1223);$from = ;$port = 0;socket_recvfrom($socket, $buf, 12, 0, $from, $port);echo "Received $buf from remote address $from and remote port $port" . PHP_EOL;?>

This example will initiate a UDP socket on port 1223 of 127.0.0.1 and print at most 12 characters received from a remote host.

参见

• socket_recv() - 从已连接的socket接收数据
• socket_send() - Sends data to a connected socket
• socket_sendto() - Sends a message to a socket, whether it is connected or not
• socket_create() - 创建一个套接字（通讯节点）