What does the switch -r mean for Firebird gbak tool?

When I run:

gbak -r

what will it do?

In Firebird < 2.0, -r will replace your currently database file with the one restored from the backup. In FB >= 2.0, you need to specify -rep for that. Take care to avoid replacing an active database.

-r[ecreate_database] o[verwrite]

http://www.destructor.de/firebird/gbak.htm

[Firebird 2.0] Restores over an existing database. This can only be performed by SYSDBA or the owner of the database that is overwritten. Do NOT restore over a database that is in use! -r is equivalent to -c. Only the "overwrite" option will restore over an existing database.

It replaces the database - ie. overwrites it.

http://pwet.fr/man/linux/commandes/gbak