PHP set_time_limit(0) long connection implementation code example

Every time we access a PHP script, we only get the return result after all PHP scripts have been executed. If we need a script to run continuously, then we have to use PHP long connection to achieve the purpose of running.

Each PHP script has a limited execution time, so we need to set the execution time of a script to unlimited through set_time_limit; then use flush() and ob_flush() to clear the server buffer and output the return value of the script at any time.

Such as the following script:

The code is as follows:

<?php 
header("Content-Type: text/plain"); 
set_time_limit(0); 

$infoString = "Hello World" . "\n"; 
while( isset($infoString) ) 
{ 
echo $infoString; 
flush(); 
ob_flush(); 
sleep(5); 
} 
?>

When we execute it, every 5 seconds, we will get a line of Hello World. If If you don't press the Stop button, the browser will continue to load line by line.

Through this method, we can complete many functions, such as robot crawlers, instant message boards and other programs.

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