Brian Fitzpatrick Brian Fitzpatrick - 1 month ago 9
HTML Question

How can I create a link to a local file on a locally-run web page?

I'd like to have an html file that organizes certain files scattered throughout my hard drive. For example, I have two files that I would link to:


  • C:\Programs\sort.mw

  • C:\Videos\lecture.mp4



The problem is that I'd like the links to function as a shortcut to the file. I've tried the following:

<a href="C:\Programs\sort.mw">Link 1</a>
<a href="C:\Videos\lecture.mp4">Link 2</a>


... but the first link does nothing and the second link opens the file in Chrome, not VLC.

My questions are:


  1. Is there a way to adjust my HTML to treat the links as shortcuts to the files?

  2. If there isn't a way to adjust the HTML, are there any other ways to neatly link to files scattered throughout the hard drive?



My computer runs Windows 7 and my web browser is Chrome.

Answer

You need to use the file:/// protocol (yes, that's three slashes) if you want to link to local files.

<a href="file:///C:\Programs\sort.mw">Link 1</a>
<a href="file:///C:\Videos\lecture.mp4">Link 2</a>

These will never open the file in your local applications automatically. That's for security reasons, and I'll get to that in the last section. If it opens, it will only ever open in the browser. If it your browser can display the file, it will. If it can't, it will probably ask you if you want to download it.

Some browsers, like modern versions of Chrome, will even refuse to cross from the http protocol to the file protocol, so you'd better make sure you open this locally using the file protocol if you want to do this stuff at all.

Why does it get stuck without file:///?

The first part of a URL is the protocol. A protocol is a few letters, then a colon and two slashes. HTTP:// and FTP:// are valid protocols; C:/ isn't and I'm pretty sure it doesn't even properly resemble one.

C:/ also isn't a valid web address. The browser could assume it's meant to be http://c/ with a blank port specified, but that's going to fail.

Your browser may not assume it's referring to a local file. It has little reason to make that assumption, because public sites usually don't attempt to link to peoples' local files.

So if you want to access local files: tell it to use the file protocol.

Why three slashes?

Because it's part of the File URI scheme. You have the option of specifying a host after the first two slashes. If you skip specifying a host, it will just assume you're referring to a file on your own PC. In other words: file:///C:/etc is a shortcut for file://localhost/C:/etc.

These files will still open in your browser and that is good

Your browser will respond to these files the same way they'd respond to the same file anywhere on the internet. These files will not open in your default file handler (e.g. MS Word or VLC Media Player), and you will not be able to do anything like ask File Explorer to open the file's location.

This is an extremely good thing for your security.

Sites in your browser cannot interact with your operating system very well. If a good site could tell lecture.mp4 to open in VLC.exe, a malicious site could tell it to open virus.bat in CMD.exe. Or it could just tell your PC to run a few Uninstall.exe files, or to open File explorer a million times.

This may not be convenient for you, but HTML and browser security weren't really designed for what you're doing. If you want to be able to open lecture.mp4 in VLC.exe, consider writing a desktop application instead.

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