[int$options = 0],
[bool$verbose = false]
This function passes the arguments to the (remote) database server. There it starts a new backup process. Therefore you won't get any responses.
A previously opened connection to the database server.
The absolute file path to the database on the database server. You can also use a database alias.
The path to the backup file on the database server.
Additional options to pass to the database server for backup. The options parameter can be a combination of the following constants: IBASE_BKP_IGNORE_CHECKSUMS, IBASE_BKP_IGNORE_LIMBO, IBASE_BKP_METADATA_ONLY, IBASE_BKP_NO_GARBAGE_COLLECT, IBASE_BKP_OLD_DESCRIPTIONS, IBASE_BKP_NON_TRANSPORTABLE or IBASE_BKP_CONVERT. Read the section about for further information.
Since the backup process is done on the database server, you don't have any chance to get its output. This argument is useless.
Returns true on success or false on failure.
Since the backup process is done on the (remote) server, this function just passes the arguments to it. While the arguments are legal, you won't get false.