The following php script works for simple linux commands, like ps -ef , but when i use ./dstat -t -a , it seems to hang and i dont get the prompt back on my local machine. Kep in mind that all commands are executed over ssh on a remote host:

<?php
$target = time() . '_' . 'txt';

if($ssh = ssh2_connect('10.1.0.174', 22)) {
    if(ssh2_auth_password($ssh, 'root', 'kmoon77')) {
        //$stream = ssh2_exec($ssh, 'whoami');
        $sCommand = 'dstat -a';
        //$sCommand = 'ps -ef';
        $stream = ssh2_exec($ssh, $sCommand);
        //$stream = ssh2_exec($ssh, 'pwd');
        stream_set_blocking($stream, true);
        $data = '';
        while($buffer = fread($stream, 4096)) {
            $data .= $buffer;
        }
        //fclose($stream);
        echo $data; // user
    }
}
?>