sleepyhead.php

<?php

declare(ticks = 1); // needed
function sig_handler($signo) {
  echo "Caught $signo...\n";
}

pcntl_signal(SIGUSR1, "sig_handler");

echo 'Hi!' . PHP_EOL;
for ($i = 0; $i < 30; $i++) {
 sleep(1); // because signals wake us up, need to sleep again
}
echo 'Bye!' . PHP_EOL;