Every time we access the PHP script, we get the returned results after all the PHP scripts are executed. If we need a script to run continuously, we need to use the php persistent connection method to achieve the running goal. Every PHP script limits the execution time, so we need to use set_time_limit to set the execution time of a script to an infinite length, and then use flush () and ob_flush () to clear the server buffer, output the return value of the script at any time.
As shown in the following script:
The code is as follows:
Header ("Content-Type: text/plain ");
Set_time_limit (0 );
$ InfoString = "Hello World". "\ n ";
While (isset ($ infoString ))
{
Echo $ infoString;
Flush ();
Ob_flush ();
Sleep (5 );
}
?>
After Execution, every five seconds, we will get a line of Hello World. if we do not press the stop button, the browser will continue loading one line without stopping.
Through this method, we can complete many functions, such as robot crawlers and instant message boards.
