Re: default mime for attaching files

[Katsumi Yamaoka <yamaoka@jpl.org>]

>>>>> In <87zm7op2y1.fsf@patagonia.sebmags.homelinux.org>
>>>>>	Sebastian P. Luque wrote:

> I often need to attach tar.gz archives in messages, and noticed that
> whenever I do 'C-c C-a' (mml-attach-file), I'm faced with the default
> "application/octet-stream".  I don't understand much about mime-types, but
> I gather that tar.gz files should be specified as "application/x-gzip".
> Browsing 'M-x customize-group mime' I can't find some relevant variable to
> set a default (and possibly other files) for files suffixed *.tar.gz.  Any
> suggestions would be welcome.

First of all, application/octet-stream for *.gz files is not so
bad choice.  OTOH, types beginning with x- are non-standard, it
suggests not all mailers support them.

In Gnus, the default type for a certain file name is determined
according to the value of the `mailcap-mime-extensions' variable.
The value of `mailcap-mime-extensions' defined in mailcap.el is
just a default value.  It will be overridden if you have the
file specified by the MIMETYPES environment variable or there
are the files ~/.mime.types, /etc/mime.types, /usr/etc/mime.types,
etc. in your system.  If you prefer application/x-gzip for *.gz
files, create the file named "~/.mime.types" with the following
contents, for example:

--8<---------------cut here---------------start------------->8---
application/x-gzip gz
application/x-tar tar
...
--8<---------------cut here---------------end--------------->8---

If you customize it while Gnus is running, you need to perform
`C-u M-x mailcap-parse-mimetypes RET' after saving the file.
In addition, you may possibly need to set the MIMETYPES
environment variable to the file name.  To do it for only Emacs,
add this line to the ~/.emacs file:

--8<---------------cut here---------------start------------->8---
(setenv "MIMETYPES" "~/.mime.types")
--8<---------------cut here---------------end--------------->8---

Regards,