how to write php script for a cron job - copy mysql database

[sfullman]

so I have my own dedi server and have root access. my db's are in /var/lib/mysql.

I need to copy one database named cpmx51 over to /home/cpmx51/backup as name:

cpmx51_bk1180

where 1 = 2011
where 180 = 180th day of the year for example.

normally I just run php files as php -f /path/to/php/file.php

but here, any one of my accounts cannot "read" the file/database since owner and group = mysql. All I really want to do is use php to do:

cp -r -p /var/lib/mysql/cpmx51 /home/cpmx51/backups/cpmx51_bk1180;

any suggestions on how to surmount the permissions issues? I'm open to other approaches.

Thanks,
Sam

[bradgrafelman]

One solution might be to do a chgrp to set the PHP script's group to the 'mysql' group and then set the setgid bit on the file; that way when executed it should inherit the mysql group's permissions.

However, is this just for a MySQL DB backup? If so, why not just use mysqldump instead?