(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)
socket_read — Reads a maximum of length bytes from a socket
   The function socket_read() reads from the Socket instance
   socket created by the
   socket_create() or
   socket_accept() functions. 
  
socketA Socket instance created with socket_create() or socket_accept().
length
       The maximum number of bytes read is specified by the
       length parameter. Otherwise you can use
       \r, \n,
       or \0 to end reading (depending on the mode
       parameter, see below).
      
mode
       Optional mode parameter is a named constant:
       
PHP_BINARY_READ (Default) - use the system
          recv() function. Safe for reading binary data.
         
        PHP_NORMAL_READ - reading stops at
          \n or \r.
         
        
   socket_read() returns the data as a string on success,
   or false on error (including if the remote host has closed the
   connection). The error code can be retrieved with
   socket_last_error(). This code may be passed to
   socket_strerror() to get a textual representation of
   the error.
  
注意:
socket_read() returns a zero length string ("") when there is no more data to read.
| 版本 | 说明 | 
|---|---|
| 8.0.0 | socketis a Socket instance now;
   previously, it was a resource. |