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
    An Interview with Eric Meyer

    Your early CSS books were instrumental in pushing my love for front end technologies. What was it about CSS that you fell in love with and drove you to write about it? At first blush, it was the simplicity of it as compared to the table-and-spacer...

  • 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...

Incredible Demos

  • By
    Disable Autocomplete, Autocapitalize, and Autocorrect

    Mobile and desktop browser vendors do their best to help us not look like idiots by providing us autocomplete, autocorrect, and autocapitalize features.  Unfortunately these features can sometimes get in the way;  we don't always want or need the help they provide.  Luckily most browsers allow...

  • By
    Using jQuery and MooTools Together

    There's yet another reason to master more than one JavaScript library: you can use some of them together! Since MooTools is prototype-based and jQuery is not, jQuery and MooTools may be used together on the same page. The XHTML and JavaScript jQuery is namespaced so the...

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!