<?php

$daemonName = 'my daemon';
$sleep = 600;
$exit = FALSE;

while (!$exit)
{
  sleep($sleep);

  $mysqli = mysqli_connect('localhost', 'db_user', 'db_passwd', 'schema');

  $query = "SELECT * FROM daemons WHERE name = '" . $mysqli->real_escape_string($daemonName) . "'";
  $result = $mysqli->query($query);
  $row = mysqli_fetch_assoc($result);

  $command = $row['command'];
  $run = TRUE;

  if ($command == 'exit')
  {
    $exit = TRUE;
    $run = FALSE;
  }
  else if ($command == 'pause')
  {
    $run = FALSE;
  }

  if ($run)
  {
     /* Daemon operations... */
  }
}