Things that are three digits?
The site that no one needed.
403JUMP is a tool designed for penetration testers and bug bounty hunters to audit the security of web applications. It aims to bypass HTTP 403 (Forbidden) pages using various techniques, including different HTTP verbs, different HTTP headers, and path fuzzing.
DiskScan is a Unix/Linux tool to scan a block device and check if there are unreadable sectors. In addition it uses read latency times as an assessment for a near failure as sectors that are problematic to read usually entail many retries (and bog the system down). This can be used to assess the state of the disk and maybe decide on a replacement in advance of its imminent failure. The disk self test may or may not pick up on such clues depending on the disk vendor decision making logic.
badblocks looks for fatal issues already happening and diskscan is for upcoming issues that can be fixed.
Also, badblocks is essentially obsolete in this day and age since the disks themselves will reallocate the data and there is no real need to map the bad blocks in the filesystem level anymore.
In the AUR. Works quite well, and sussed out a dying drive on Leandra.
What to do when you see the dreaded "Call to undefined function filter_var()" error message in your Apache logs. It's actually easier that it sounds but I recommend matching the version of the PHP source you download to that installed from your distro's official package.
A Stack Overflow thread on writing HTTP error handlers for web applications based upon CherryPy.
How to add a 404 error handler to a CherryPy application. The example is sufficiently generic that it can be adapted to whatever fix you need (i.e., it shows how the CherryPy errorpage*() methods are called).
A FOSS utility for investigating Tor hidden services. Searches for configuration errors and information leaks. Written in golang. In the AUR. CLI tool but the Onionscan Correlation Lab is a webapp that lets you analyze the data visually.
The Wikipedia page describing all of the known more-or-less standard HTTP status codes. Useful for people developing web applications.