To create entries in the mailcap file, packages need to create a file in the /usr/lib/mime/packages directory. In this file goes the verbatim desired mailcap entries. In addition to the standard mailcap options (described below) is a new priority option. Specifying this will provide for simple ranking of programs within a given mime type. An animation viewer, for example, may be able to display a static picture, but probably wouldn't be the best choice and so would give an option like priority option is omitted, a value of 5 is used.
The following are standard options that can be specified in the mailcap entry. Options are separated by semicolons (;) but must all be on the same line. Each line should look like:
mime/type; viewer; option; another=val; etc; priority=5
Mime types of the form
Specifies the program to run to view a file of the given content-type. Actually, the This option connot be omitted.__ When writing an entry that has no viewer, use a value of false in this space.
These options are modifiers to all the commands specified on the command line.
Note: When testing for X by looking at the DISPLAY environment variable, please use one of:
Many programs recognize these strings and optimize for them.
These options provide additional information about the given content-type.
Packages that wish to provide MIME access to themselves should not depend on, recommend, or suggest mime-support. Instead, they should just put something like the following in the postinst and postrm scripts.