How to Add or Modify MIME Types

Language:

Create the Overrides.xml source XML file containing the definitions for the MIME types.
- To set the definitions for all users, put the file in the /usr/share/mime/packages directory.
- To set the definitions for an individual user, put the file in the ~/.local/share/mime/packages directory.
If the file already exists, open it.
Update the MIME database by running the update-mime-database command.
- If you are setting the definitions for all users:
```
# update-mime-database /usr/share/mime
```
- If you are setting the definitions for an individual user:
```
# update-mime-database ~/.local/share/mime/packages
```
U pdate the MIME database by running the update-mime-database command.
```
# update-mime-database /usr/share/mime
```

Use the gnomevfs-info command to verify your changes .

For example, the gnomevfs-info command displays the following output when you run the command for a SVG file. Note that the default application for this MIME type is eog.desktop.

$ gnomevfs-info mime-diagram.svg
Name              : mime-diagram.svg
Type              : Regular
MIME type         : image/svg+xml
Default app       : eog.desktop
Size              : 14869
Blocks            : 32
I/O block size	: 4096
Local             : YES 
SUID              : NO
SGID				: NO
Sticky            : NO
Permissions       : 600644
Link count        : 1
UID               : 1000
GID               : 100
Access time       : Wed Feb 22 18:24:47 2006
Modification time : Wed Feb 22 18:24:42 2006
Change time       : Wed Feb 22 18:24:42 2006
Device #          : 775
Inode #           : 297252
Readable		: YES
Writable          : YES
Executable        : NO
$

For more information about default applications, see Registering Applications for MIME Types.

Example 6-2 Creating an application/x-newtype MIME Type

Create a new file, test.xyz, in your home directory.
Use the gnomevfs-info command to find the file's MIME type.
```
$ gnomevfs-info text.xyz
```
The MIME type for this file should be detected as text/plain because no glob patterns or magic rules match the file.
Note - When no glob patterns or magic rules match a file, then the file is resolved to the text/plain MIME type if the file contains textual data or application/octet-stream for binary data. If the file is empty, then the type is identified as text/plain MIME type.

Create the Overrides.xml file or if the file already exists, modify the file.

The sample XML file is as follows:

<?xml version='1.0' encoding='utf-8'?>
<mime-info xmlns="http://www.freedesktop.org/standards/shared-mime-info">
	<mime-type type="application/x-newtype"> 
	<comment>new mime type</comment>
	<glob pattern="*.xyz"/> 
	</mime-type>
</mime-info>

Update the MIME database by using the update-mime-database command.
```
# update-mime-database /usr/share/mime
```
Use the gnomevfs-info command to verify that your change has taken effect.
```
$gnomevfs-info testing.xyz | grep MIME
MIME type : application/x-newtype
```
You should see that the MIME type for the testing.xyz file is resolved as application/x-newtype.