This function is EXPERIMENTAL. The behaviour of this function, the name of this function, and anything else documented about this function may change without notice in a future release of PHP. Use this function at your own risk.
The function socket_write() writes to the socket socket from buffer.
The optional parameter length can specify an alternate length of bytes written to the socket. If this length is greater then the buffer length, it is silently truncated to the length of the buffer.
Returns the number of bytes successfully written to the socket or FALSE one error. 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: 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.
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.