Re: extview.el --- open files with external viewer

[Peter S Galbraith]

Ted Zlatanov <address@hidden> wrote:

> On 28 Mar 2006, address@hidden wrote:
> 
> > The code below advises find-file and launches an external viewer if the
> > file name matches any of the prefedefined patterns. This way any file
> > can be opened in the traditional way or via dired or globalff, etc. and
> > it is passed to an external application if Emacs cannot handle the
> > content.
> >
> > At the moment only pdf files are handled, but it is trivial to add
> > others.
> [...]
> > (defvar extview-application-associations
> > '(("\\.pdf$" . "acroread"))
> > "List of (REGEXP . APPLICATION) descriptors which are tested for the
> > file name to be opened. The first matching application is used to open
> > the file. If no application matches then normal `find-file' is
> > executed.")
> 
> Just a suggestion: look at the ~/.mailcap, /etc/mailcap, and
> /etc/mime.types files (on my Fedora Core 5 and Debian systems, at
> least).  They are a pretty good way of associating file viewers with
> file extensions.  You could at least populate
> extview-application-associations from those files on startup, even if
> you don't consult them every time the user asks to open a file (I
> would advise the latter).
> 
> The Gnus code has a mailcap.el file, in which the function
> mailcap-parse-mailcaps parses the appropriate files.  I would suggest
> looking at it to see how your idea can be done correctly.  mailcap.el
> is in the Emacs Lisp tree as well, if you don't want to depend on Gnus
> itself but still want to use this functionality.
> 
> All the best
> Ted

See also `mailcap-mime-info' which handles the reading of the mailcap
file.   MH-E uses this as well when you click on attachments.

Peter