This capplet allows you to configure how files of various types
should be handled. File type (formally called MIME type)
describes what kind of data and in what format the file
contains. For each of the file types, you can set the icon to be
used by the File Manager, the default application to be used to
open files of this type, etc. For example, file type
image/jpeg is used for image files in
JPEG format; by default, it is opened using
File Manager's built-in graphics viewer.
The File types capplet shows you all file types currently known
to Gnome. For each file type, it shows a short description
(e.g., PDF document), the file type name
(e.g., application/pdf), etc. Clicking on a
file type in the list shows you more information about this gile
type, namely:
Brief description (e.g., PDF document)
"Official" file type name, or the MIME
type (e.g., application/pdf). These
names should be of the form
type/subtype, where
type describes general type of data
(image, text, audio, video, or application) and
subtype gives complete
specification.
Icon to be used for files of this type by File
Manager.
Default action to be performed when you click on the
file in the File Manager window. There are two possible
types of default actions: view the file using one of File
Manager built-in "viewers" or open the file
using an external application. In fact, you can have a whole
list of applications that can be used to open the file. One
of these applications is used by default when you click on
file; the other applications will be included in the pop-up
menu for files of this type (to get the pop-up menu, click
on the file with the right mouse button in the File Manager
window and select Open With).
Extensions: these are used by File Manager and other
Gnome applications to determine file type of a given
file. The most common and simplest way of doing this is by
matching the filename extension: for example, extension
pdf is used for files of type
application/pdf.
NOTE FOR ADVANCED USERS
In fact, Gnome File Manager can also use more elaborate
methods of determining file type than just matching the
extensions. Advanced users who want to know more
about this should take a look at the file
PREFIX/mime-info/gnome-vfs.mime, where
PREFIX=/usr/share or
/usr/local/share depending on your
system's configuration.
By far the most common type of editing a file type is changing
the default action associated with a given file type. To do so:
Click on the file type in the list.
Select the type of default action
(Use Viewer or Open with
Application)
Select the application/viewer you want to be
the default from the drop-down list. If you don't see an
application you want in this list, click on the
Edit List button. It will show you
the list of all application which are currently included
in the pop-up menu for this file type. Now click on
Add application button and enter
the application name (e.g., Gnome PS
viewer) and command used to launch this
application (e.g., ggv).
You can also change other properties of a file type:
To change the icon used by a file type, click on the
Change icon button.
To change file type description, just click
inside the text field containing description and edit
it.
To edit the list of extensions associated
with a file type, click on the Change file
extensions button. This will produce a window
showing the list of file extensions currently associated
with this file type. To remove an extension from the list,
select it with the mouse and then click
Remove button. To add a new
extension, click on Add button and
enter the new extension in the appearing dialog. Do not type
the leading dot: if you want to add extension
pdf, you should type in
pdf, not .pdf.
To edit the list of applications associated with the file
type (these applications appear in the menu when you right-click
on the file of this type in the File Manager and select
Open with), click on the
Edit List button. This will show
the list of all applications associated with this file
type. You can remove any of the applications from the
list, edit an existing application (this allows you to
cahnge the name under which this application appears in
the menu and the command used to launch this application),
or add a new application. Instead of removing of
application from the list, you can also temporarily
disable it by unchecking it in the list. Such a disabled
application will not be shown in the menu for the files of
this type.
To delete a file type, select it in the file type list and
press Delete this Mime type button. To
add a new file type, press Add new Mime
type button. You will be prompted to enter the
file type name and description. It is strongly advised that
you follow the MIME standard: file type name should be of the
form type/subtype, where
type is one of the following five
standard types: text,
audio,image,
video, or
application (the last one should be
used if none of the first four are suitable).
After you have entered the file type name and description, the
new file type is added to the list. Now you can select it in
the list and choose an icon, file extensions and default
action for this file type as described in the section called Editing a file type.
If you (or someone else) did something wrong in this capplet,
you can discard all your changes and
restore the system default values for all the settings
controlled by this capplet (i.e., file types, default actions,
icons, etc). To do so, click on Revert to system
defaults button. Note that this will erase all
your changes; you can not "undo" this action.