Read Write CSV with SPL functions PHP

rw.php

<?php
(PHP_SAPI !== 'cli' || isset($_SERVER['HTTP_USER_AGENT'])) && die('cli only');
class RW_SPL{

	public function __construct() {
		$this->filename = './item.db';
		$this->rows = array("item"=>0,"type"=>1,"price"=>2,"age"=>3,"location"=>4);
	}
	private function _read(){
		file_exists($this->filename) or die("File doesn't exist\r\n");
		$file = new SplFileObject($this->filename);
		$file->setFlags(SplFileObject::READ_CSV | SplFileObject::READ_AHEAD | SplFileObject::SKIP_EMPTY | SplFileObject::DROP_NEW_LINE);
		$file->setCsvControl(',', '"', '\\'); // this is the default anyway though
		return $file;		
	}
	public function _add($args){
		array_shift($args);
		$file = fopen($this->filename,"a+");
		fputcsv($file,$args);
		fclose($file);
	}
	public function search($args){
		$res = array();
		list($action,$search_type,$search_value) = $args;
		foreach($this->_read() as $row){
			if($row[$this->rows[$search_type]] == $search_value){
				array_push($res, $row);
			}
		}	
		return $res;
	}
}
echo "Command:\n";
echo " Add an item\n";
echo " add <item> <sale/rent> <price_usd> <location> <age>\n";
echo " Search by item/location/age/price \n";
echo " search <type> <value>\n";
echo " q\n";
echo " Quit\n";


$cmd = array();
$stdin = fopen("php://stdin", "r");
$rw = new RW_SPL();
while (!feof($stdin)) {
    echo " >> ";
    $input = fgets($stdin);
    $cmd = explode(" ", trim($input));
    $cmd[0] = strtolower($cmd[0]);
    switch ($cmd[0]) {
        case "add":
            if (count($cmd) != 6) {
                echo "Wrong number of parameters.\n add <item> <sale/rent> <price> <location> <age> \n";
                continue;
            }
            $rw->_add($cmd);
            break;
        case "search":
            if (count($cmd) != 3) {
                echo "Wrong number of argments for search.\n search <type> <value>\n";
                continue;
            }
			foreach($rw->search($cmd) as $row)
				print implode(' ',$row)."\r\n";
            break;
        case "q":
            exit(0);
            break;
        default:
            echo "This version only supports add,search commands.\n";
    }

}
?>