# socket_write

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

socket_write — Write to a socket

### 说明

socket_write ( resource `$socket` , string `$buffer` [, int `$length` = 0 ] ) : int

The function socket_write() writes to the `socket` from the given `buffer`.

### 参数

`socket`

`buffer`

  The buffer to be written.

`length`

  The optional parameter `length` can specify an alternate length of bytes written to the socket. If this length is greater than the buffer length, it is silently truncated to the length of the buffer.

### 返回值

Returns the number of bytes successfully written to the socket 或者在失败时返回 `FALSE`. The error code can be retrieved with socket_last_error(). This code may be passed to socket_strerror() to get a textual explanation of the error.

> Note:

> It is perfectly valid for socket_write() to return zero which means no bytes have been written. Be sure to use the === operator to check for `FALSE` in case of an error.

### 注释

> Note:

> socket_write() does not necessarily write all bytes from the given buffer. It's valid that, depending on the network buffers etc., only a certain amount of data, even one byte, is written though your buffer is greater. You have to watch out so you don't unintentionally forget to transmit the rest of your data.

### 参见

- socket_accept() - Accepts a connection on a socket
- socket_bind() - 给套接字绑定名字
- socket_connect() - 开启一个套接字连接
- socket_listen() - Listens for a connection on a socket
- socket_read() - Reads a maximum of length bytes from a socket
- socket_strerror() - Return a string describing a socket error