Get File MIME Type from Command Line

By  on  

I've gotten skilled at shell scripting over the years. I love a good GUI but knowing how to automate makes you a much more powerful engineer. Much of my scripting requires recursing over directories and processing a file if it meets a given criteria, which is often file extension or MIME type.

You can use the following shell command to get a file's MIME type:

file --mime-type -b Downloads/main.js
# text/plain

file --mime-type -b Downloads/logo.jpg
# image/jpeg

It's important to use the brief (-b) option in the command or you may receive an error message.

MIME type is used for validation and any number of other informational use cases. Luckily the file command and and a flag is all you need!

Recent Features

  • By
    JavaScript Promise API

    While synchronous code is easier to follow and debug, async is generally better for performance and flexibility. Why "hold up the show" when you can trigger numerous requests at once and then handle them when each is ready?  Promises are becoming a big part of the JavaScript world...

  • By
    CSS @supports

    Feature detection via JavaScript is a client side best practice and for all the right reasons, but unfortunately that same functionality hasn't been available within CSS.  What we end up doing is repeating the same properties multiple times with each browser prefix.  Yuck.  Another thing we...

Incredible Demos

  • By
    Redacted Font

    Back when I created client websites, one of the many things that frustrated me was the initial design handoff.  It would always go like this: Work hard to incorporate client's ideas, dream up awesome design. Create said design, using Lorem Ipsum text Send initial design concept to the client...

  • By
    MooTools Kwicks Plugin

    I wrote a post titled Get Slick with MooTools Kwicks ages ago. The post was quite popular and the effect has been used often. Looking back now, the original code doesn't look as clean as it could. I've revised the original...

Discussion

    Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!