backup postgres

[donadioema]

Salve ragazzi ho trovato su un sito questo script che effettua backup di postgres usando proc_open e pg_dump e utilizzando queste variabili $dbName, $dbUser, $dbPwd, $backupPath funziona benissimo e salva il file nella directory $backupPath.

<<?php
function postgresBackup($dbName, $dbUser, $dbPwd, $backupPath)
{
    $fSuccess = FALSE;
    // get rid of try..catch for PHP 4 or less
    try {
        ignore_user_abort(TRUE);
        $file = date('YmdHis') . "_pgDBBackup.sql";
        $buffer = '';
        $logFile = "/tmp/pgdump-error-output.txt";
        $descriptorspec = array(
          0 => array("pipe", "r"),  // stdin
          1 => array("pipe", "w"),  // stdout
          2 => array("file", "$logFile", "a") // stderr
        );
        // may need entire path to pg_dump
        $cmd = "pg_dump -c -D -U {$dbUser} {$dbName}";
        $process = proc_open("$cmd", $descriptorspec, $pipes);
        if (is_resource($process)):
            // $pipes now looks like this:
            // 0 => writeable handle connected to child stdin
            // 1 => readable handle connected to child stdout
            // Any error output will be written to log file
           
            // send the password and close the stdin
            fwrite($pipes[0], "{$dbPwd}\n");
            fclose($pipes[0]);
   
            // read in the dump data and close stdout
            while(!feof($pipes[1])):
                $buffer .= fgets($pipes[1], 1024);
            endwhile;
            fclose($pipes[1]);
   
            // close any pipes before calling
            // proc_close to avoid a deadlock
            $return_value = proc_close($process);
   
            // write the file to disk and return true
            if($return_value == 0):   
                // this could be modified to automatically
                // force a file download if run from a web page
               
                // may need to change this line for PHP 4 or less
                file_put_contents($backupPath . $file, $buffer);
                // successfully created backup
                $fSuccess =  TRUE;
            endif;
        endif;
    } catch(Exception $ex) {
        error_log($ex->getMessage(), 3, $logFile);
        return FALSE;    // return so log file is not deleted
    }
    // comment out the following for debug information if backup fails
    @unlink($logFile);
    return $fSuccess;
}
// example usage
postgresBackup('mydb','myuser','pwd',"/home/db/");
?>

e poi utilizzando il comando fpassthru per leggere il buffer. ma il tutto va in errore evidentemente sbaglio qualcosa.
Qualcuno può aiutarmi please.
Grazie in anticipo