In order to create a blank db4 database with PHP script, all you need is to use this code:
<? $srcfile="/path/to/db4file"; $id=dba_open($srcfile, 'c', 'db4'); dba_close($id); ?>
If you are getting an error like
PHP Fatal error: Uncaught Error: Call to undefined function dba_open() in...
Ask your server administrator to add dba support to PHP. For a rpm-based installation the command is:
yum install php-dba