[O] Exporting a given file (not buffer)

[Marcin Borkowski]

Hello fellow Orgers,

I need a function, which – given an org file's name – opens it silently,
exports to a file, and closes.

I can write it myself, but maybe such a function already exists?  It
seems that `org-export-to-file' exports the current buffer, so I could
make a new buffer, `insert-file-contents' the given file to it, turn on
`org-mode', do my export and close the buffer (probably using
`with-temp-buffer' in the first place) – but is it really necessary to
code it, or is it ready somewhere in Org?

TIA,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University