Broken Link Checker for WordPress

Sometimes, links get broken. A page is deleted, a subdirectory forgotten, a site moved to a different domain. Most likely many of your blog posts contain links. It is almost inevitable that over time some of them will lead to a “404 Not Found” error page. Obviously you don’t want your readers to be annoyed by clicking a link that leads nowhere. You can check the links yourself but that might be quite a task if you have a lot of posts. You could use your webserver’s stats but that only works for local links.

So I’ve made a plugin for WordPress that will check your posts (and pages), looking for broken links, and let you know if any are found.

Download it now! (40 KB)

Note : This page, and the feature list below are slightly out of date as a major update has been released recently (see details). I’ll get around to updating this page eventually.

Features

  • Checks your posts (and pages) in the background (whenever the WP admin panel is open ).
  • Detects links that don’t work and missing images. Checks both internal and outbound links.
  • Notifies you on the Dashboard if any problems are found.
  • Link checking intervals can be configured.
  • New/modified posts are checked ASAP.

The broken links show up in the Manage -> Broken Links tab. If any invalid URLs are found a notification will also show up in the sidebar on the Dashboard.

The Broken Links tab displays a list of invalid URLs found along with the relevant posts and the anchor text of the links. “View” and “Edit Post” do exactly what they say and “Discard” will remove the message about a broken link, but not the link itself (so it will show up again later unless you fix it; this plugin doesn’t modify your links).

By default all old posts/links are re-checked every 72 hours, or you can set a different time period.

Notes (Semi-Technical)
I realize there’s a lot of features that could be added to improve this plugin considerably. However, this release is intended to “test the waters” and see if there’s demand for a plugin like this, so I only implemented the most basic functions. The plugin has been upgraded to be slightly beyond “basic” ;)

I thought about using WP’s pseudo-cron to run the link checker by schedule and decided against it. AFAIK the cronjobs execute when a page is requested; since this plugin does some lengthy processing it may increase page load times unacceptably when used in this manner. That’s why I set it to run the checks asynchronously (AJAX) and invisibly in the admin panel.

Installation
Just like any other WordPress plugin -

  1. Download (see below).
  2. Unzip.
  3. Upload the broken-link-checker folder to you wp-content/plugins directory.
  4. Activate the plugin in the Plugins tab.

Upgrading

  1. Deactivate the plugin (important!).
  2. Do steps 1.-3. from “Installation”.
  3. Upload the broken-link-checker folder to you wp-content/plugins directory.
  4. Re-activate the plugin in the Plugins tab.

DownloadCC-GNU GPL
Version 0.5.3 : broken-link-checker.zip (40 Kb)

Requirements

  • WordPress 2.7 or later
  • MySQL 4.1 or later

Starting with version 0.5 this plugin is only compatible with WordPress 2.7 and up. Older versions (e.g. ver. 0.4.14) should work with WP 2.1 – 2.6.x.

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This entry was posted on Sunday, August 5th, 2007 at 22:59 and is filed under Applications, Blogging. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

895 Responses to “Broken Link Checker for WordPress”

Pages: « 1 … 20 21 22 23 24 25 26 27 [28] 29 30 » Show All

  1. 806
    Steve Portigal says:
    October 16, 2009 at 02:14

    I checked with my ISP and we have neither have safe_mode nor open_basedir enabled.

  2. 807
    White Shadow says:
    October 16, 2009 at 03:13

    Alas, after a lot of testing and googling, I’ve discovered that this is probably a CURL bug. So it’s not something I can fix.

  3. 808
    Steve Portigal says:
    October 16, 2009 at 03:29

    Bummer; I wish I had done the redirects before we moved servers; it was great stuff that I wouldn’t otherwise find. I really appreciate your effort in tracking this down, but just so I understand a little bit more, is CURL an ingredient in your plugin? Is it something that is installed on my ISP? Is there something they can patch if I ask them? Etc. etc.

  4. 809
    White Shadow says:
    October 16, 2009 at 12:52

    CURL is a command-line tool and a software library for transferring data over a variety of Internet protocols (e.g. HTTP). The library component (called libcurl) is installed on a lot of servers and can be used by PHP. I use it in my plugin because it’s generally a very robust and versatile way to query remote URLs.

    You could ask them to upgrade to libcurl 7.18.1 or later (the latest version is currently 7.19.6). That should fix the bug.

  5. 810
    Angel Romero says:
    October 16, 2009 at 17:10

    Hey there, I’ve got this error once I installed the plugin.
    database_name.wp_blc_links’ doesn’t exist

    Any ideas? I tried activating and deactivating…no luck

  6. 811
    White Shadow says:
    October 16, 2009 at 20:18

    No useful ideas so far, but the next version will be a bit more verbose when reporting errors like that (which should help us locate the bug) and do it upon activation so that you can see that there’s a problem right away.

  7. 812
    6 plugins para el mantenimiento de tu Wordpress | triunfoweb.com says:
    October 17, 2009 at 06:29

    [...] Broken link checker: Se encarga de revisar los enlaces salientes de nuestro blog y comprobar que estos están activos aún o no. Muy útil para artículos antiguos. [...]

  8. 813
    Texas Heat says:
    October 17, 2009 at 06:52

    Every time I update Broken Like Checker, I have the same 15 broken links appear. All of them contain “2009/08/category/” in the URL. I remove this from the link and every thing is fine until the next upgrade. Is there something within the plugin that creates this problem? Or is it being created by some other plugin?

  9. 814
    Asmodiel says:
    October 17, 2009 at 19:01

    Hi there!
    I have a problem with your plugin… every time I update it, I have to change one line (this update l. 2218) into $path = ini_get(’upload_tmp_dir’);

    It is the opendir restriction, so do me a favor please and change it :D

    Have a nice day,
    Asmodiel

  10. 815
    White Shadow says:
    October 17, 2009 at 19:22

    @ Keyword-SEO-guy : I’m guessing those links use relative URLs, right? This is a bug in the plugin; I’m uploading a fixed version to wordpress.org as I write this.

    @ Asmodiel : Alright, though I’ll a bit differently :P

  11. 816
    Steve Portigal says:
    October 17, 2009 at 20:04

    re: 809

    My ISP upgraded the CURL library. I checked the plugin’s debug info:
    PHP version 5.2.5
    MySQL version 5.0.41-community
    CURL version 7.19.5
    Snoopy Installed
    Safe mode Off
    open_basedir On
    Redirects may be detected as broken links when open_basedir is on.
    Lockfile /tmp/wp_blc_lock

    however. I see that open_basedir shows as on, but Support has denied that it’s actually turned on. They referred me to http://jade.rahul.net/~ldhesi2/info.php which lists config info for the server, in which I see that open_basedir has “no value”

    So the CURL issue is dealt with, but I’m not sure about the open_basedir situation, and meanwhile, I rescanned everything and there are no redirects showing.

    Thanks for your ongoing help with this!!!

  12. 817
    White Shadow says:
    October 17, 2009 at 21:15

    Regarding open_basedir, the plugin just reports what PHP tells it. I’ll make it display the value it sees for the open_basedir setting, maybe that will provide some clues.

  13. 818
    Dingoe says:
    October 18, 2009 at 12:00

    I noticed that your broken-link-checker is not internationalized. Please consider to do so, it’s not much work and might widen your range of fans ;-) . I made a start by adding a domain name to your __(’textstrings-to-be-localized’) and the 1 _e(’textstrings-to-be-localized’) you have in your broken-link-checker.php page. Not all english terms are hereby translated though. You might want to look at the http://codex.wordpress.org/I18n_for_WordPress_Developers/ page.

    I uploaded the edited broken-link-checker.php, together with the broken-link-checker-nl_NL.po and mo file in a zip file to:
    http://rapidshare.com/files/294540358/broken-link-checker.zip

  14. 819
    gaianorm says:
    October 18, 2009 at 12:31

    HI,
    I agree with dingoe, as I told you some weeks ago… i can also add Italian po file.
    byez
    G.

  15. 820
    Steve Portigal says:
    October 19, 2009 at 19:53

    re: 817

    Here’s what the debug info says now (after your update)

    PHP version 5.2.5
    MySQL version 5.0.41-community
    CURL version 7.19.5
    Snoopy Installed
    Safe mode Off
    open_basedir On ( /home/portigal/:/tmp:/usr/local/lib/php/ )
    Redirects may be detected as broken links when open_basedir is on.
    Lockfile /tmp/wp_blc_lock

    Interesting (to my naive self) that the open_basedir is giving a different readout here than http://jade.rahul.net/~ldhesi2/info.php which says “no value”

  16. 821
    White Shadow says:
    October 19, 2009 at 20:04

    Interesting, yes.

  17. 822
    Steve Portigal says:
    October 20, 2009 at 04:56

    I was able to check /usr/local/lib/php.ini

    [relevant lines, via grep, but I can get more of the file if need be]

    ; open_basedir, if set, limits all file operations to the defined directory
    ;open_basedir =

    So there’s no value set there. But I suppose something else could be changing the setting – another plugin, something in WP, etc. I don’t really know what it is or if that’s even possible, but I wonder if that’s a source for investigating?

  18. 823
    White Shadow says:
    October 20, 2009 at 12:58

    According to PHP docs the open_basedir directive can only be set in php.ini and httpd.conf in your version of PHP. You’d need at least PHP 5.3.0 to set it from a script, so I’m fairly certain plugins/WP can’t change it in your case (PHP 5.2.5).

    Maybe open_basedir isn’t the problem here. You could try (re-)enabling redirect detection manually : comment out lines 161 and 163 in link-classes.php like this :

    //if ( !blcUtility::is_safe_mode() && !blcUtility::is_open_basedir() ) {
	curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
//}
  19. 824
    Tinh says:
    October 20, 2009 at 13:01

    I tried to deactivated and reactivated the plugin but the error on the table is still there

  20. 825
    White Shadow says:
    October 20, 2009 at 21:39

    Did you get an error when reactivating (you should have if it couldn’t create the table)? If yes, what was it?

  21. 826
    Dingoe says:
    October 21, 2009 at 10:29

    for my own Wordpress blog I have rewritten the broken-link-checker.php file and made my own broken-link-checker-nl_NL.mo file. I will post this rewritten file and the broken-link-checker.pot file in a zipped file on Rapidshare for those who want a localized plugin.

    http://rapidshare.com/files/295841715/broken-link-checker.zip

  22. 827
    Wordpress plugins for affiliate websites : Travel Affiliate says:
    October 22, 2009 at 00:54

    [...] Broken link checker – Helps my users and is good for SEO by identifying broken links within my sites. From the dashboard you can unlink or edit the link to something that will work. [...]

  23. 828
    Asmodiel says:
    October 23, 2009 at 00:08

    Hi there!

    The Problem with the open_basedir as I’ve written above is not really fixed with the last update. While using the proposed ini_get(’upload_tmp_dir’); it works… Maybe you should really consider changing it :)

    I could write a german and polish localisation…. :)

  24. 829
    White Shadow says:
    October 23, 2009 at 01:14

    Interesting. As a test, could you try switching the order the plugin tries the directories like this (around line 2220) :

    $path = ini_get('upload_tmp_dir');
if ( $path && is_writable($path)){
	return trailingslashit($path) . 'wp_blc_lock';
}
 
//Try the system-wide temp directory
$path = sys_get_temp_dir();
if ( $path && is_writable($path)){
	return trailingslashit($path) . 'wp_blc_lock';
}

    The reason I’m reluctant to implement your suggestion exactly as written is because it doesn’t account for other users’ situation. (What if someone doesn’t have an upload dir. set? What if it gets automatically cleared at inopportune moments? Etc.)

    So I see there’s great demand for localisation(s). Okay, I’ll get started on that sometime next week :)

  25. 830
    Michael Garmahis says:
    October 23, 2009 at 22:57

    I installed this plugin but it immediately paralyzed both backend and frontend. I’d better use Xenu’s Link Sleuth for now.

  26. 831
    steve portigal says:
    October 24, 2009 at 01:47

    re: 823
    (more naive questions, sorry) Where do I find link-classes.php? It’s not part of the WP install as far as I can tell…

  27. 832
    White Shadow says:
    October 24, 2009 at 01:51

    It’s one of the plugin’s files, in wp-content/plugins/broken-link-checker/.

  28. 833
    Steve Portigal says:
    October 24, 2009 at 08:29

    Well, I tried that. I rechecked all links and then I created a post with http://chittahchattah.blogspot.com which redirects to http://www.portigal.com/blog

    1. Post published on : October 23, 2009
    2. Link last checked : October 23, 2009
    3. HTTP code : 200
    4. Response time : 0.215 seconds
    5. Final URL : http://chittahchattah.blogspot.com
    6. Redirect count : 0
    7. Instance count : 1

    1. Log : === First try : 200 ===

    HTTP/1.1 200 OK
    Content-Type: text/html; charset=UTF-8
    Expires: Sat, 24 Oct 2009 05:26:05 GMT
    Date: Sat, 24 Oct 2009 05:26:05 GMT
    Cache-Control: public, max-age=0, must-revalidate, proxy-revalidate
    Last-Modified: Mon, 13 Jul 2009 22:44:07 GMT
    ETag: “5bd197ab-8424-4f4a-aacb-ebb0252da666″
    X-Content-Type-Options: nosniff
    X-XSS-Protection: 0
    Content-Length: 0
    Server: GFE/2.0

    Link is valid.

    Debug info:
    PHP version 5.2.5
    MySQL version 5.0.41-community
    CURL version 7.19.5
    Snoopy Installed
    Safe mode Off
    open_basedir On ( /home/portigal/:/tmp:/usr/local/lib/php/ )
    Redirects may be detected as broken links when open_basedir is on.
    Lockfile /tmp/wp_blc_lock

    In other words, it didn’t make any difference. No redirects out of my 7000+ links :(

  29. 834
    20 plugins indispensables pour Wordpress | Tendances du Web says:
    October 24, 2009 at 19:11

    [...] – Broken Link Checker scannera régulièrement vos pages, et vous indiquera, sur le dashboard d’administration, [...]

  30. 835
    White Shadow says:
    October 24, 2009 at 19:49

    http://chittahchattah.blogspot.com uses a META redirect, which is not directly supported by CURL and similar libraries.

    But that still doesn’t explain why other redirects wouldn’t show up, and I’m running out of ideas. Khm. Okay, here’s one more test – download this archive, unzip it, upload the test_redirect.php file to your server and run it. It should output a bunch of information; paste it here.

    The script is basically a greatly simplified variant of the link checking code that tries to load http://w-shadow.com/redirect302.php – a page I created specifically to test redirects – and displays various information about the result(s).

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