What are the URIs starting with file:// or application://?

Question

Using Linux, I have more than once seen URIs of files and applications starting with file:// and application://.

What are those URIs and how to use them?

Answer 1

Quoting Wikipedia:

The file URI scheme is a URI scheme specified in RFC 1630 and RFC 1738, typically used to retrieve files from within one's own computer.

and RFC 1738:

The file URL scheme is used to designate files accessible on a particular host computer. This scheme, unlike most other URL schemes, does not designate a resource that is universally accessible over the Internet.

A file URL takes the form: file://host/path

where host is the fully qualified domain name of the system on which the path is accessible, and path is a hierarchical directory path of the form directory>/directory/.../name.

As a special case, host can be the string localhost or the empty string; this is interpreted as `the machine from which the URL is being interpreted'.

Most browsers support file:// URI, co you can open file from your disk by using them in your browser address bar.

I don't think that application:// URI is standarized - there is no info about it on Wikipedia and in RFC's on IETF site and in IANA site, so usage of this URI scheme is rather application specific and designed for application internal needs.