The function socket_read() reads from the socket resource socket created by the socket_create() or socket_accept() functions. 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 type parameter, see below).
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: socket_read() returns a zero length string ("") when there is no more data to read.
Optional type parameter is a named constant:
PHP_BINARY_READ - use the system recv() function. Safe for reading binary data. (Default in PHP >= 4.1.0)
PHP_NORMAL_READ - reading stops at \n or \r. (Default in PHP <= 4.0.6)
See also socket_accept(), socket_bind(), socket_connect(), socket_listen(), socket_last_error(), socket_strerror() and socket_write().