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
    Regular Expressions for the Rest of Us

    Sooner or later you'll run across a regular expression. With their cryptic syntax, confusing documentation and massive learning curve, most developers settle for copying and pasting them from StackOverflow and hoping they work. But what if you could decode regular expressions and harness their power? In...

  • By
    How I Stopped WordPress Comment Spam

    I love almost every part of being a tech blogger:  learning, preaching, bantering, researching.  The one part about blogging that I absolutely loathe:  dealing with SPAM comments.  For the past two years, my blog has registered 8,000+ SPAM comments per day.  PER DAY.  Bloating my database...

Incredible Demos

  • By
    Create Your Own Dijit CSS Theme with LESS CSS

    The Dojo Toolkit seems to just get better and better.  One of the new additions in Dojo 1.6 was the use of LESS CSS to create Dijit themes.  The move to using LESS is a brilliant one because it makes creating your own Dijit theme...

  • By
    Cross Browser CSS Box Shadows

    Box shadows have been used on the web for quite a while, but they weren't created with CSS -- we needed to utilize some Photoshop game to create them.  For someone with no design talent, a.k.a me, the need to use Photoshop sucked.  Just because we...

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!