The registry is a sort-of database and is manipulated using certain specialised tools (like regedt32.exe, etc.). Unfortunately Microsofts tools do not offer a lot of possibilities to automatically (that is: non-interactively) edit the registry at all, so you probably will need some replacement tool for this. This includes saving (part of) the registry into a file and then read such a file and add its contents to the registry again. Therefore, how in detail you have to do that depends on the tool you finally decide to use.
No Linux does have a registry (and neither do most Unixes). All configuration information is stored in clear-text files as a principle, because these can be manipulated by simple text editors and/or any text-manipulating tool. This way it is easy to write scripts and other software to (semi-)automatically rewrite such configuration information. This adds a lot of possibilities to the administration/configuration of Unix-like systems Windows-systems do seriously lack.
Nevertheless the registry was invented on a Unix system (IBMs AIX, to be precise), where it is called "ODM". In fact it was licensed by Microsoft from IBM way back in the beginning of the nineties, IIRC.
The ODM (Object Data Manager) serves a similar purpose in AIX as the registry in Windows (
here is the link to wikipedia), but is not as exclusively used as there. The classical config files are still there and only some parts of the configuration (logical volume manager information, software inventory, extended user attributes, etc.) is stored in the ODM. For some aspects there are daemons which propagate settings done in the ODM to the "real machine" and vice versa so that machine configuration and ODM content remains consistent.
For instance: user information is still handled in the classical files ("/etc/passwd", "/etc/group", ...), but extended attributes of user accounts (max time for a password to expire, etc.) are stored in the ODM. There is a command ("chuser") to manipulate user accounts which will do all the necessary changes to the ODM as well as the files automatically.
Another example: static routes are stored in the ODM as part of the systems attributes. There is a command "chsys", which would do the necessary changes (like issuing a "route" command wiht the appropriate options) and also stores the changes in the ODM. The user can use the "route" command alone too, generating a change in the routing table which will not survive reboot. "chsys" itself has a flag to change the system immediately, coming into effect only after next reboot or both. It would be possible (but is not recommended) to use low-level commands ("odmchange", ...) directly to manipulate the ODM the same way "chsys" does and the effect would take place with the next reboot.
This is another major difference between ODM and the registry: the ODM comes with all the necessary tools to manipulate it (odmget, odmdelete, odmchange, ...).
I hope this helps.
bakunin