Root nameserver check

Submitted by davidc on Wed, 10/09/2003 - 00:43

This form queries all the nameservers for the root you've specified to find out what their records show for the NS of the domain in question. This is useful if you have submitted nameserver changes and you don't know whether they are yet in any or all roots. It returns a list of what each root (gtld, cctld etc) nameserver is serving as NS records. Repetitive, automated or abusive use of this page is strictly prohibited. If you want to run this yourself, download the source.

Simple DHTML scrolling control

Submitted by davidc on Fri, 27/12/2002 - 00:32

This article examines the construction of a scroller control, enabling selection from a group of items where the currently selected element is visible and new elements are scrolled in to replace it. It makes use of the CSS clip property to control the scrolling. This code could also be used as a basis for other scrolling transitions, such as in a slideshow.

Visual Subnet Calculator

Submitted by davidc on Tue, 22/10/2002 - 01:25

This tool lets you quickly subnet IPv4 networks, visualise them, and split or join them with a single click. It also shows the address range, subnet mask, and number of hosts for each subnet. You can save and load your arrangement using bookmarks.

Access the Visual Subnet Calculator.

This was written in 2002, though I still use it constantly. One day I intend to make an equivalent for IPv6.

Update 20/9/2017 - the source is now on GitHub under the zlib license.

PHP Shared Memory Debugger

Submitted by davidc on Tue, 09/07/2002 - 07:53

This utility allows you to see the contents of a shared memory segment created using the shm_* functions in PHP. Unlike the shmop functions, which allow you to read and write raw data in a shared memory segment, these are designed for PHP only and consist of serialized PHP variables in a linked list.

Submitted by davidc on Wed, 03/07/2002 - 23:28

This program converts MRTG .log files to the correct .rrd format for Cricket.

I haven't used MRTG since 2002, when this script was written, so I make no guarantees as to its functionality, nor can I help with any problems.

This is based on code by Wrolf Courtney, Russ Wright and Alan Lichty.

Friendly Forms: Labels and Access Keys

Submitted by davidc on Sun, 21/04/2002 - 04:46

In this article I describe two under-used HTML features that can be used to improve the usability of your HTML forms.

All common desktop window managers support the labelling of input fields, so by clicking on say the label of a checkbox, the checkbox itself is selected. They also support keyboard shortcuts (access keys) to move around the form quickly.

Checkboxes and radio buttons are inherently small and thus a hard target to click on. Windows applications almost always allow you to click on label text to use the form element. Why should web pages be any different? I've gotten so used to putting labels on my form elements that I get frustrated when using websites that have not done so.