demo for php pcntl

pcntl-example.php

<?php
foreach (['a', 'b', 'c'] as $x) {
  $pid = pcntl_fork();
  if ($pid === -1) {
    echo 'fork Error';    
  } elseif (!$pid) {
    $i = 0;
    while (true) {
      $t = time();
      echo "sub(${x}, ${i}) ${t}\n";
      $i++;
      if ($i >= 5) {
         break;
      }
      sleep(3);
    }
    echo "sub(${x}, ${i})bye...\n";
  }
}
while (-1 !== pcntl_waitpid(0, $states)) {
  $states = pcntl_wexitstatus($states);
  echo "pcntl_wexitstatus = ${states}\n";
}