Get Redirect URL with cURL

By  on  

URL redirects can be glorious or annoying depending on which side of them you are on and which side you want to be on.  Redirects are helpful for vanity URLs (useful in advertising) but sometimes they're annoying in that they could potentially break your code if you encounter a redirect you weren't anticipating.

The useful and amazing cURL command line utility allows you to fetch an address and return its final destination URL:

# "/css" doesn't exist but WordPress tries to find the closest match
# and then redirects to it ("/css-animation-callback")

curl -Ls -w %{url_effective} -o /dev/null https://davidwalsh.name/css

# Outputs: https://davidwalsh.name/css-animation-callback

The url_effective variable is what we're after.  The L directive tells cURL to follow redirects, the s directive tells cURL to be silent (i.e. not output the page contents).  You provide the URL, cURL follows it to its endpoint -- easy!

Recent Features

  • By
    CSS Animations Between Media Queries

    CSS animations are right up there with sliced bread. CSS animations are efficient because they can be hardware accelerated, they require no JavaScript overhead, and they are composed of very little CSS code. Quite often we add CSS transforms to elements via CSS during...

  • By
    9 Mind-Blowing WebGL Demos

    As much as developers now loathe Flash, we're still playing a bit of catch up to natively duplicate the animation capabilities that Adobe's old technology provided us.  Of course we have canvas, an awesome technology, one which I highlighted 9 mind-blowing demos.  Another technology available...

Incredible Demos

  • By
    Fixing sIFR Printing with CSS and MooTools

    While I'm not a huge sIFR advocate I can understand its allure. A customer recently asked us to implement sIFR on their website but I ran into a problem: the sIFR headings wouldn't print because they were Flash objects. Here's how to fix...

  • By
    Send Email Notifications for Broken Images Using MooTools AJAX

    One of the little known JavaScript events is the image onError event. This event is triggered when an image 404's out because it doesn't exist. Broken images can make your website look unprofessional and it's important to fix broken images as soon as possible.

Discussion

  1. J-K. Solbakken

    Follow a URL using JavaScript: https://www.npmjs.com/package/linkfollower

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