PHP: How to track the timeout of the absence of input data?

Question

There is code which recieves input lines from STDIN:

#!/usr/bin/php
<?php
while (false !== ($line = fgets(STDIN))) {
      if (preg_match('/start/',$line)) {
         echo $line , "\n";
      }
}
?>

My question is: how to track the timeout of the absence of input data for 1 minute and inform if in case?

Answer 1

I resolved my issue using answer of hek2mgl from here [PHP CLI - Ask for User Input or Perform Action after a Period of Time

This is my code :

#!/usr/bin/php
<?php
echo "input something ... (5 sec)\n";
$stdin = fopen('php://stdin', 'r');

while(true) {
$read = array($stdin);
$write = $except = array();
$timeout = 5;

    if(stream_select($read, $write, $except, $timeout)) {
          $line = fgets($stdin);
          if (preg_match('/start/',$line)) {
                echo $line , "\n";
          }
    } else {
       echo "you typed nothing\n";
    }
}
?>