socket_setopt

Function name: socket_setopt()

Applicable version: PHP 4 >= 4.3.0, PHP 5, PHP 7

Function description: The socket_setopt() function is used to set the value of the socket option.

Syntax: bool socket_setopt ( resource $socket , int $level , int $optname , mixed $optval )

parameter:

• $socket: Required, a socket resource that has been created.
• $level: Required, the protocol level to which the option belongs. Commonly used protocol levels include SOL_SOCKET, SOL_TCP, SOL_UDP, etc.
• $optname: Required, name of the option.
• $optval: Required, value of option.

Return value: Return true on success, and false on failure.

Example:

 // 创建一个TCP socket $socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP); // 设置socket的超时时间为5秒$timeout = 5; socket_setopt($socket, SOL_SOCKET, SO_RCVTIMEO, array('sec' => $timeout, 'usec' => 0)); // 设置socket的发送缓冲区大小为8192字节$bufferSize = 8192; socket_setopt($socket, SOL_SOCKET, SO_SNDBUF, $bufferSize); // 设置socket的延迟关闭为1秒$delay = 1; socket_setopt($socket, SOL_SOCKET, SO_LINGER, array('l_onoff' => 1, 'l_linger' => $delay)); // 设置socket的重用地址选项为true socket_setopt($socket, SOL_SOCKET, SO_REUSEADDR, true); // 关闭socket socket_close($socket);

In the example above, a TCP socket is first created using the socket_create() function. Then use the socket_setopt() function to set several different options:

• The reception timeout time is set to 5 seconds, and the SO_RCVTIMEO option is used.
• The send buffer size is set to 8192 bytes and the SO_SNDBUF option is used.
• The delay shutdown time is set to 1 second, and the SO_LINGER option is used.
• The reuse address option is set to true, and the SO_REUSEADDR option is used.

Finally, the socket was closed using the socket_close() function.

Please note that the specific option name and available values ​​depend on the protocol and operating system used. It is recommended to consult the relevant documentation for specific options and values ​​before using the socket_setopt() function.