php infinite loop and comet? - php

Question

Something seems wrong with my php script, but I have no idea what it is. The only possible thing that seems to be wrong is something to do with the cache, but I am not sure. Here's my script, I'll tell you what's happened below the code:
<?php
set_time_limit(0);
header('Content-Type:text/event-stream');
$prevmod=$lastmod=filemtime('chattext.txt');
function waitformod(){
global $lastmod;
global $prevmod;
while($prevmod==$lastmod){
usleep(100000);
clearstatcache();
$lastmod=filemtime('chattext.txt');
}
echo 'data:'.file_get_contents('chattext.txt').PHP_EOL.PHP_EOL;
flush();
$prevmod=$lastmod;
}
while(true){
waitformod();
}
?>
This is supposed to be used with the JavaScript EventSource and send the contents of chattext.txt whenever it is modified. The file does not output anything, however. I think it is because of the infinite loop. Is there any way to fix this?

Answer 1

Does something like this work better?
<?php
set_time_limit(0);
header('Content-Type:text/event-stream');
$prevmod = $lastmod = filemtime('chattext.txt');
function waitformod(){
global $lastmod;
global $prevmod;
while($prevmod == $lastmod) {
usleep(100000);
clearstatcache();
$lastmod = filemtime('chattext.txt');
}
echo 'data:'.file_get_contents('chattext.txt').PHP_EOL.PHP_EOL;
flush();
$prevmod = $lastmod;
}
while(1) {
waitformod();
}
Your current code looks like it reads the file, outputs it, waits for it to change, and then terminates.