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

Browser blocking: fight or flight?

Modern browsers are like bouncers at a nightclub; keeping out troublemakers. Here, the troublemakers are file:/// protocol links from pages being served over http(s). They're blocked to prevent Sketchy McSketchface from accessing your local file system.

<!-- Why the bouncer might not let you in -->
<a href="http:///Skethcy_McSketchface/hacking_your_system.docx">Open Definitely Not a Virus</a>
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For Chrome on Windows 7 and similar, make sure you're pointing to the right house by providing an absolute path and using forward slashes (/), not backslashes (\).

IIS virtual directory: building guest homes for your files

If you're dealing with complex applications or multiple files, consider setting up an IIS virtual directory. This solution is like building guest homes for your files. Yes, files need vacation too! It essentially enables you to access your files using an HTTP link, reducing restrictions.

But remember, even with vacation homes, you need to have proper security measures (Don't forget to lock the doors!). So, authenticate access to your IIS, to keep your files safe.

<!-- Linking to your file's vacation home -->
<a href="http://yourIIS/help_me_I_am_trapped_in_a_computer.docx">Open Vacation Document</a>
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Desktop applications and blobs: how to play nicely with file handlers

What's the best way to get a local file to open in its associated application instead of the browser? Well, the answer isn't as easy as OpenSesame.exe. Web pages don't usually have permission to directly invoke local file handlers for obvious security reasons. However, a desktop application or a browser extension can help in these situations.

For web applications, you can use JavaScript's URL.createObjectURL() to generate a special local blob URL. It's like rolling a snowball with just the right bit of snow.

// This function spits out snowballs (blob URLs). Cool, isn't it?
let snowball = URL.createObjectURL(yourLocalFile);
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And remember to free up the used memory space once you're done with your blob by invoking URL.revokeObjectURL(). Because, hey, not everyone loves a snowball fight.

// Remember to clean up the snowballs! No one likes a mess.
URL.revokeObjectURL(snowball);
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Incorrect approaches and syntax pitfalls: common mistakes when walking the file:// tightrope

The idea of using the target attribute with a value akin to "explorer.exe" to tap dance your way into opening a file through the Windows Explorer - that's a no-no.

Additionally, bear in mind that the file:// protocol can be your best friend or worst enemy, depending on whether you're using it correctly. The secret handshake is using three slashes (file:///), followed by the path to your local file.

<!-- Use three slashes, not two. The difference? Tons of painful debugging -->
<a href="file://nope/nope/nope">Wrong Local File</a>
<a href="file:///yep/yep/yep">Right Local File</a>
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Visual representation

Let's be poetic for a moment. Creating a local file link in HTML is like making a shortcut to a book in a library (📚):

<a href="file:///absolute/path/to/your/file">Open Local File</a>
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Imagine a library card catalogue:

Card Catalogue (📚): [Book A, Book B, Book C]

Suddenly, you pull open the right drawer, revealing the exact card for "Your Local File":

🗂️ -> 🏷️: [Your Local File]

Then, click… and you're beamed up directly to your "book's" shelf:

You click 🖱️ -> You get 📖 (Local File)

HTML's lesser-known party tricks for local file linking

Of course, HTML offers extras to further enhance how your local file links operate. Who doesn't love a bit of magic?

For your 'ta-da' moments, you might use:

• The download attribute that suggests the file should be downloaded when the link is activated. It's like going shopping, but without leaving the comforts of your local library.

  <a href="file:///path/to/file" download>Download Local File</a>
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• The target attribute which controls how the link opens in the browser. Not quite like ordering the file to open in Adobe Reader, but close enough.

  <a href="file:///path/to/file" target="_blank">Open in New Tab</a>
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And of course, HTML5 lets you interact with the FileSystem API for more advanced file handling on a rainy day.

Beyond Google Chrome: cross-browser issues

Remember, not all browsers play by the same rules. They're more like different nightclubs with various policies for dealing with file:// access. Some may require you to tweak settings or flags, while others might be cool with local file:/// links.

Organizing your files: a guide for the scatterbrained

For those dealing with distributed projects or those working on a network, consider investing time in accurate file referencing. It's easy to end up with broken links which are as useful as an ejection seat on a helicopter.