Backup and Restore MySQL database in PHP -

i trying use php backup , restore mysql database:

backup:

$dbhost = 'localhost'; $dbuser = 'root'; $dbpass = 'dbpass'; $dbname = 'test';  $output = "d:/backup/test.sql"; exec("d:/xampp/mysql/bin/mysqldump --opt -h $dbhost -u $dbuser -p $dbpass $dbname > $output"); echo "backup complete!"; 

restore:

$dbhost = 'localhost'; $dbuser = 'root'; $dbpass = 'dbpass'; $dbname = 'test';  $output = "d:/restore/test.sql"; exec("d:/xampp/mysql/bin/mysql --opt -h $dbhost -u $dbuser -p $dbpass $dbname < $output"); echo "restore complete!"; 

but both not working. when backup complete check test.sql file blank. when restore complete, database still blank.

how can fix this?

script backup using php

<?php define("backup_path", "/home/abdul/");  $server_name   = "localhost"; $username      = "root"; $password      = "root"; $database_name = "world_copy"; $date_string   = date("ymd");  $cmd = "mysqldump --routines -h {$server_name} -u {$username} -p{$password} {$database_name} > " . backup_path . "{$date_string}_{$database_name}.sql";  exec($cmd); ?> 

script restore

<?php  $restore_file  = "/home/abdul/20140306_world_copy.sql"; $server_name   = "localhost"; $username      = "root"; $password      = "root"; $database_name = "test_world_copy";  $cmd = "mysql -h {$server_name} -u {$username} -p{$password} {$database_name} < $restore_file"; exec($cmd);  ?>