Ubuntu – How to change the MIME type for a file

MIME types are just a way to name types. They don't have anything to do with how the type of a file is determined.

There are two ways to determine the type of a file: a) Look at its extension and hope that it is accurate or b) look at its contents and then guess based on that. If a file has no extension b is the only option.

Many (binary) file formats have a specific header that you can look at to determine their type. This makes option b quite reliable for those types.

Plain text file formats can often be determined by their structure (if a file contains a lot of html tags, it's probably a html file).

On unix and linux systems you can use the file command line utility to find out the type of a file based on its contents.

File manager often use some combination of option a and b (e.g. look at the file extension first, if it's not known (or the file does not have an extension), look at the contents).

A file's type is not stored as metadata on common linux file systems.

Here is a set of instructions that should get you a custom icon for hwp files.

Open a terminal :

• Check the MIME type exists : grep 'hwp' /etc/mime.types

  if you get an output resembling application/x-hwp hwp skip the next step.

• Create the MIME type sudo -H gedit /etc/mime.types and add the line application/x-hwp hwp

• Add the icon (which must be called application-x-hwp.svg):

  sudo cp PathToIcon/application-x-hwp.svg /usr/share/icons/gnome/scalable/mimetypes
  

  (don't forget to replace PathToIcon)

Got the information from here