mod_brokenlink

Source

HowToCompile

For users

What is mod_brokenlink

mod_brokenlink is a module for Apache HTTP Server that, installed on the link-target host (target) notifies to the link-origin host (origin) of the existence of broken* links.

* broken (404), or permanently moved (301) or whichever status you had defined in its configuration.

When does it work

When a non-existent page* is requested to the target.

* page, or picture, or any other resource with an URL.

Where the notifications are recorded

The notifications are recorded into the origin's access log.

But I want to know MY broken links

This will not happen until your target servers have a feature like this.

Meanwhile, your server will be at least reporting to others if they have a broken link to you.

For developers

How is the origin known?

The origin is usually known since it comes as the value of the "Referer" HTTP header of the request itself.

How is the notification performed?

The notification is done by an access from the target to a non-existent (but clearly defined) resource in the origin. This intended-to-fail access, as any other failed access, is then recorded into the access log of the origin. Thus, the access log acts also as "broken links log" at the origin.

On quality

The code is clean and well structured:

But some experienced C/Apache modules programmer should take a look into it to find quality issues.