ProcessInfo.php

<?php

class ProcessInfo {

    /** @var array $processes */
    protected $processes = array();

    /**
     * Find a processes
     *
     * @param      $pid
     * @param null $default
     *
     * @return null
     */
    public function findProcessByPid($pid, $default=null)
    {
        // Get the most current list of processes
        $this->getCurrentProcesses();

        // If the process exists
        if ( isset($this->processes[$pid]) )
        {
            return $this->processes[$pid];
        }
        else
        {
            return $default;
        }
    }

    /**
     * @param bool $current_user_only
     *
     * @return array
     * @throws \Exception
     */
    public function getCurrentProcesses($current_user_only=true)
    {
        // Run `ps aux` or `ps ux` to get the list of running processes
        /*
         * -a      Display information about other users' processes as well as your own.  This will skip any pro-
             cesses which do not have a controlling terminal, unless the -x option is also specified.
         * -u      Display the processes belonging to the specified usernames.
         * -x      When displaying processes matched by other options, include processes which do not have a con-
             trolling terminal.  This is the opposite of the -X option.  If both -X and -x are specified in
             the same command, then ps will use the one which was specified last.
         */
        // Will set the option to ux is only needing processes for the current user
        $command = array("ps", ($current_user_only ? "ux" : "aux"));

        $process_builder = new ProcessBuilder($command);
        $process = $process_builder->getProcess();

        $process->run();

        if ( !$process->isSuccessful() )
        {
            throw new \Exception("The 'ps' process was not successful: " . $process->getErrorOutput());
        }
        // Get the process output
        $output = $process->getOutput();
        // Convert the output into an arrow of rows
        $output = explode("\n", $output);

        // Get the leading row which happens to be the header row
        $header = array_shift($output);
        // Split the header row on spaces
        $header = preg_split('/ +/', $header);
        // Get the number of columns from the header
        $header_count = count($header);

        // Initialize an array to hold all of the processes
        $this->processes = array();

        foreach ( $output as $process )
        {
            if ( empty($process) )
            {
                continue;
            }
            $process = preg_split('/ +/', $process);

            // The first few columns will match the header, but the last column (COMMAND) could be in multiple
            // array fields because processes are broken up by spaces. So grab the known headers first and then
            // add any remaining array fields from process to the COMMAND field
            $tmp_process = array();
            foreach ( $header as $header_name )
            {
                // Cut the column out of the process
                $column = array_splice($process, 0, 1);
                $tmp_process[$header_name] = $column[0];
            }
            if ( !empty($process) )
            {
                // Add the remaining process fields to the COMMAND field in the process definition
                $tmp_process[$header[$header_count-1]] .= " " . implode(" ", $process);
            }
            $this->processes[$tmp_process["PID"]]= $tmp_process;
        }

        return $this->processes;
    }

}