Fetch can automatically “pass-off” downloaded files to other applications; this feature is called post-processing, and is configured in the Post-Processing dialog. [Note: Post-processing requires System 7.0 or later]. In that dialog you can create a list of post-processing actions. An action consists of two pieces of information: the kind of file that the action applies to, and the application that this kind of file should be opened with. The kind of file is specified by type/creator codes, and the application by its signature code. For instance, one action could specify files with the type code of “TEXT” and the creator code of “ttxt”, and the application signature of “MSWD.” This would mean that TeachText files (which have type “TEXT” and creator “ttxt”) should be automatically opened with Microsoft Word (which has the signature “MSWD”). Alternatively, an action could specify a type of “TEXT” and a creator of “****”; the special code “****” matches anything, so this action would apply to all files of type “TEXT” (i.e. all text files). Finally, the application signature can be left blank. In this case the file will be opened by the application that typically opens it, just as if you double-clicked on the file in the Finder.
The codes that Fetch uses to identify files and applications are rather cryptic, so Fetch provides an alternative means for entering them. The “Choose Example...” and “Choose Application...” buttons allow you to select the kind of file or application you are interested in, leaving Fetch to extract the necessary codes.
Post-processing actions can be enabled and disabled. This allows you to define actions and turn them off temporarily, without having to re-enter them later. Fetch comes with several post-processing actions defined; they give some examples of how this feature can be used.