mysqldump通过PHP系统生成一个空白文件（）

Question

Before you say there are other questions like this, but none of the answers I've seen worked, so I'm making a fresh question.

I'm trying to use mysqldump via system() with this command:

$backup_path = $_SERVER['DOCUMENT_ROOT'] . '/website/acp/backup/';
$backup_name = $backup_path . $dbname . '.backup.' . date('l.dS.F.Y.g.iA') . '.sql';

$command = 'mysqldump ' . $dbname . ' -u ' . $dbuser . ' -p' . $dbpasswd . ' > ' . $backup_name;

system($command, $returned);

print_r($returned); 

$returned outputs 127 and a blank file with a size of zero KB is located in the backup folder, now when I echo $command and then enter it into Terminal, it works perfectly and generates a full backup of the database. This is the part I don't understand, why is it not working well in the system() call but in Terminal it works just fine?

Answer 1

This is because when running mysqldump you are required to enter the password, even if you specify it with -p

This should be helpful : http://www.techiecorner.com/1619/how-to-setup-mysqldump-without-password-in-cronjob/