Run an arbitrary file as a windows bat file from Firefox?

Say I've got a windows batch file with a file extension .batscript, and say I've got a web server set up t开发者_Python百科o serve it with a content-type of application/x-batscript. How can I set up Firefox 4 to "always open" this file so that it runs as a standard batch file would? (I have access to the PCs but want avoid creating/installing external programs/extensions/plugins)

I can't use a straight .bat because Firefox doesn't allow those to be opened directly; they have to be saved and run separately (for obvious security reasons).

The standard way to run a batch file is cmd /c %1 where %1 is the path to the bat file, but this doesn't work when %1 is a path to a file with a custom file extension (such as .batscript) because cmd looks up what application %1 should be opened with, so adding a direct file association via the registry doesn't work (it recursively opens cmd prompts).

Instead, I found a work around where I temporarily copy my .batscript file to a .bat file and run it, using registry entries like this, which allows me to double click on a .batscript file to run it. But Firefox doesn't respect these platform file associations!

Ok, so Firefox wants me to define my file type associations separately for each content-type: fair enough, file extensions & content-types aren't always the same. But I can only get Firefox to run discrete applications, and a batch script needs to be run with cmd.exe /c %1 not just cmd %1.

Does anybody know of a way to force Firefox to either use the system file association or allow launching arbitrary programs with command line parameters?

(For those wondering, the use case is similar to "an internal web app which allows users to run a local program with a varying amount of command line parameters by clicking on a link" - alternative solutions to these small "breaking out of the sandbox" problems are also welcome!)

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I think you need to edit the MimeTypes.rdf file. For more information see also this page.