将db备份为xml时遇到mysqldump问题

Question

I'm trying to backup one of my databases with mysqldump and I'm trying to export it to an xml file which already exists. Here is what I have:

<?php
$dbUser = 'user';    // db User
$dbPass = 'pass';    // db User Password
$dbName = 'db';      // db name
$dest   = $_SERVER['DOCUMENT_ROOT'] . 'backup'; // Path to directory

class MySQLDump {
private $cmd;

function MySQLDump($dbUser,$dbPass,$dbName,$dest) {
    $fname = $dbName.'.xml';
    $this->cmd='mysqldump -X -u'.$dbUser.' -p'.$dbPass.' '.$dbName.
        ' >'.$dest.'/'.$fname;
}

public function backup() {
    system($this->cmd, $error);
    if($error) {
        trigger_error ('Backup failed: ' . $error . '<br />Attempted: ' . $this->cmd);
    }
}
} // end class def

$mysqlDump = new MySQLDump($dbUser, $dbPass, $dbName, $dest);  
$mysqlDump->backup();
?>

This always generates the error thrown in the backup function. Here is a sample of $cmd's output:

mysqldump -X -udan -pdanPass danDB >/var/www/prod/dan/web/backup/danDB.xml

Any idea what's going wrong? I've never really used mysqldump so I'm not sure if I'm approaching this correctly. Any help is greatly appreciated.

Answer 1

try adding a space between -u and your $dbUser.