Re: using libmagic in Emacs?

[Eli Zaretskii]

> From: Juri Linkov <address@hidden>
> Cc: address@hidden,  address@hidden
> Date: Mon, 31 Aug 2009 19:17:52 +0300
> 
> >> > PLEASE do not base Emacs infrastructure on external programs, unless
> >> > they come with Emacs.
> >>
> >> There are many features in Emacs that depend on external programs,
> >> e.g. `ls' for dired, `find' and `grep', `man', `ispell', `shell',
> >> `gdb', `diff', VCS tools, etc.
> >
> > I said infrastructure, not features.  Of those you mentioned only `ls'
> > is used in infrastructure, and that's precisely why we had to write
> > ls-lisp.el.
> 
> `mailcap-file-default-commands' is not infrastructure.  It's one
> small feature.

A feature is something that stands on its own.  I don't think
`mailcap-file-default-commands' qualifies, nor would any other
function that returns something related to a file's type.  A feature
would _use_ these to actually do something useful with the file.

> >> My patch fails gracefully when `file' is not available, I tried
> >> removing `file' without any problem.  The function just returns nil.
> >
> > And that is graceful how?
> 
> When it returns nil, then default commands are the same as provided
> by mailcap for plain text files, i.e. `less', `konqueror', etc.

Which is clearly un-graceful in my book.