adding mimetypes in Ubuntu 14.04

Question

Ok, so here's what I want to do:

I have a file with a specific extension (*.ipynb) that I want to connect with a specific program. Ubuntu however thinks it is a text/plain file.

There are a lot of questions about this topic here on AskUbuntu, but non of them worked. I also tried to follow the instructions that are given here: https://help.ubuntu.com/community/AddingMimeTypes - did not work.

Since this is definitely a problem a lot of users experience, can anyone post an answer that explains how to do this?

Answer 1

This worked for me as well! Figured I might as well post it as an answer - https://wiki.archlinux.org/index.php/Default_Applications#Custom_file_associations :

Custom file associations

The following method creates a custom mime type and file association manually. This is useful if your desktop does not have a mime type/file association editor installed. In this example, a fictional multimedia application 'foobar' will be associated with all *.foo files. This will only affect the current user.

First, create the file ~/.local/share/mime/packages/application-x-foobar.xml:

mkdir -p ~/.local/share/mime/packages
cd ~/.local/share/mime/packages
touch application-x-foobar.xml

Then edit ~/.local/share/mime/packages/application-x-foobar.xml and add this text:

<?xml version="1.0" encoding="UTF-8"?>
<mime-info xmlns="http://www.freedesktop.org/standards/shared-mime-info">
    <mime-type type="application/x-foobar">
        <comment>foo file</comment>
        <icon name="application-x-foobar"/>
        <glob-deleteall/>
        <glob pattern="*.foo"/>
    </mime-type>
</mime-info>

Note that you can use any icon, including one for another application.

Next, edit or create the file ~/.local/share/applications/foobar.desktop to contain something like:

[Desktop Entry]
Name=Foobar
Exec=/usr/bin/foobar
MimeType=application/x-foobar
Icon=foobar
Terminal=false
Type=Application
Categories=AudioVideo;Player;Video;
Comment=

Note that Categories should be set appropriately for the application type (in this example, a multimedia app).

Now update the applications and mime database with:

update-desktop-database ~/.local/share/applications
update-mime-database    ~/.local/share/mime

Programs that use mime types, such as file managers, should now open *.foo files with foobar. (You may need to restart your file manager to see the change.)