Asynchronous shell exec in PHP

"> /dev/null 2>/dev/null &"

" &> /dev/null &"

<?php
    `echo "the command"|at now`;
?>

$cmd = 'nohup nice -n 10 /usr/bin/php -c /path/to/php.ini -f /path/to/php/file.php action=generate var1_id=23 var2_id=35 gen_id=535 > /path/to/log/file.log & echo $!';
$pid = shell_exec($cmd);

mycommand -someparam somevalue &

start mycommand -someparam somevalue

$pid=pcntl_fork();
 if($pid==0)
 {
   posix_setsid();
   pcntl_exec($cmd,$args,$_ENV);
   // child becomes the standalone detached process
 }

 // parent's stuff
 exit();

#!/bin/sh
mkfifo trigger
while true; do
    read < trigger
    long_running_task
done

/**
 * Asynchronously execute/include a PHP file. Does not record the output of the file anywhere.
 * Relies on the PHP_PATH config constant.
 *
 * @param string $filename  file to execute
 * @param string $options   (optional) arguments to pass to file via the command line
 */
function asyncInclude($filename, $options = '') {
    exec(PHP_PATH . " -f {$filename} {$options} >> /dev/null &");
}