kaashif's blog

Programming, software freedom and Unix

Reviving a Sun Ultra 5 workstation

I recently got an old Sun Ultra 5 working. It wasn’t too difficult, but I needed to dig up a few old serial cables…

It already had SunOS 5.8 installed, but I put OpenBSD 6.1 on it, since I need a modern OS to actually do anything with it.

Sorting a ton of mail

Migrating mail servers is a tricky business, especially when one server doesn’t have IMAP set up. The easiest way is to download all the mail and reupload it to the new mail server.

This seems simple enough, but I ran into problems. After all, I was going from an IMAP server somewhere to a maildir (no IMAP sync tool supports mbox for some reason) to an mbox through procmail to a directory of mboxes. Not trivial.

Moving to my own email server

There I was, a loyal user of http://mail.zoho.com, when I decided to download all of my emails. For archival purposes, you know.

So I fired up mbsync, set everything up, let ’er rip, but after only about 10,000 emails downloaded, I got this error:

IMAP command 'AUTHENTICATE PLAIN <authdata>' returned an error: NO [ALERT] Your account is currently not accessible via IMAP due to excessive usage. Kindly try after some time.
*** IMAP ALERT *** Your account is currently not accessible via IMAP due to excessive usage. Kindly try after some time.

What sort of…anyway, this was unacceptable, so I decided to set up my web server as a mail server.

Hardware Census

Before I get my Sun Ultra 5 working and can write something about that, I thought I’d go through all the hardware I’m using right now and the OSes I’m running on them. Spoilers: it’s all OpenBSD and Debian.

Cutting down memory usage of a Haskell web app

You may have heard of the Star Trek script search tool at http://scriptsearch.dxdy.name. I’m writing a similar thing for Stargate. The difference is, of course, is that my tool will be running on some crappy Amazon AWS t2.nano with no RAM.

The first prototype was written in Python, but the parsing code was always written in Haskell (Parsec is great). I decided to move everything into Haskell so there wouldn’t be this redundancy of parsing in Haskell then serializing to disk then reading it from Python…one codebase for everything would be much simpler.

I wrote up a quick Haskell version, but there was one small problem when I tried to use it:

$ ./stargate-search
Setting phasers to stun... (port 5000) (ctrl-c to quit)

That’s right, the OOM killer had to step in and put my app down like the sloppy wasteful piece of junk it was.

How could I fix this?

Trying out DragonflyBSD

So I was setting up a laptop I had just picked up, when it came to deciding what OS to install on it. Obviously, I’d probably end up installing some Linux and maybe also OpenBSD (hard drives are huge nowadays, I could fit hundreds of OSs on there). While I had tried out FreeBSD and NetBSD, DragonflyBSD had never been on my radar.

It still isn’t, really, but I thought I’d try it out on an old laptop, just to see what it was like. It went pretty well, but there were a few oddities and one or two kind of weird design choices.

Playing around with distcc

Today, I decided to install Gentoo on a spare machine I had lying around, since I was bored. Obviously, the first issue I ran into was that emerge x11-base/xorg-server was taking a really long time to run since the Xorg server is a pretty bloated program. Then emerge firefox was taking forever too.

One solution (for Firefox anyway) was to use the provided binary packages, this meant firefox-bin for Firefox. But this means I abandon all of the nice features (for me, that means USE flags) that Gentoo offers. If I’m going to download a load of binaries that I can’t customize, why not just install Debian?

So the solution is to speed up compilation. That means putting more CPU cores to work. But my poor old ThinkPad only has 2 cores! This is where distcc comes in.

Backing up PGP private keys

There are hundreds of blog posts about backing up your PGP keys around on the internet. Most of them just say something like: put a passphrase on it, keep it on a USB stick, a CD, a floppy disk, or something like that. These are all very useful ways to back important stuff up - in fact, I just restored a backup of my GPG keys from a CD after deleting them by accident. These mediums are, however, not going to survive for many decades like paper can. And if you store to a writeable medium like a rewritable CD, DVD, USB stick or floppy, there is still the danger of you trying to restore then accidentally deleting your backup. Or, more likely, you write over it without realising many months later that you wrote a Linux distro or movie to that DVD that had your only PGP key backup.

Making a list of the websites of people on nixers.net

I wanted to make a list of the websites of the people on the website http://nixers.net, and I decided to solve it not by asking people to tell me what their sites were called, but by scraping the forum.

I didn’t scrape the whole forum, I just scraped one topic on the forum that I created a few years ago: https://nixers.net/showthread.php?tid=1547

Sharing /home between OpenBSD and Debian

Some people reading this might be thinking: “hey, it’s really easy to do this, why is he writing an article on this?”. You are partially right, this should be really easy, but there are some weird things that happened while I set this up that I feel should have been written down somewhere, so my fear that I was completely borking my system would have been assuaged.

Converting my blog to frog

What is frog?

Frog is a static website generator written in Racket. It does the same sort of thing as Jekyll, Hakyll and other software like that, some of which I’ve used in the past.

Hacking StumpWM with Common Lisp

Before a few weeks ago, I was always one of those people who said that Lisp isn’t useful, it’s not type-safe, it’s not pure, Haskell is better etc etc ad nauseam. All of that may be true for writing some sorts of programs, but Lisp (well, Common Lisp anyway) provides something a lot more pervasive.

What does pervasive mean? Well, right now, I’m controlling my window

How to get a list of processes on OpenBSD (in C)

Is it portable?

First off, the information in this post definitely doesn’t apply to Linux (as it has a completely different way of doing things) and may or may not apply to other BSDs (I see that NetBSD and FreeBSD both have similar, maybe identical, kvm(3) interfaces). There certainly isn’t anything in POSIX to make this standard. The only real reason

Iodine is cool

I know that sometimes, I’ve bene stuck in an airport or in a coffee shop without internet. That’s annoying in and of itself, but it’s even more annoying when there’s a WiFi hotspot nearby, but it requires you to pay £4/hour or something crazy like that.

You can still connect to the network, it’s just that whatever URL you

Rainbow brackets in Emacs

You know something that really annoys me? When I’m writing some Racket, Clojure, or any other Lispy language, and my editor won’t cooperate. Emacs is far, far, better than most other editors for this sort of thing, mostly due to paredit-mode and SLIME (and geiser-mode, and clojure-mode, and evil-mode, and…), but there’s still one problem I hadn’t solved until recently.

OpenShift vs Heroku: Haskell

There are a few Platform as a Service (PaaS) services out there, and the most famous is probably Heroku. I know I’ve had people come up to me and suggest using Heroku for the next big thing they’re planning. There is a problem with Heroku: it’s not free (libre). That didn’t stop me from at least trying it out to see what all the fuss was about.

Quaternions, spinors and rotations

Earlier, I was trying to find something I could talk about at my school’s maths society. It had to be something exciting, useful, or at least beautiful in some way. I really wanted to do something on quaternions and vectors, because it seemed fun. The problem came when I realised I had to do something more substantial than stand there and explain something that boring. Then I saw this quote:

ShareLaTeX on OpenBSD

The other day, I was trying to access http://sharelatex.com at school, and it didn’t really work, probably due to a combination of Internet Explorer and possibly an overzealous filter that could have been blocking something. That’s what I thought, anyway, until I tried it on Chrome and it still didn’t work. Odd. The best solution was obviously to set up my own ShareLaTeX instance on my server.

Switching to Mercurial

UPDATE: I now use Mercurial on the client side (i.e. everything I do locally involves hg) and Git on the server-side. It just makes it easier to mirror to Gitorious, GitLab, etc. You can view all the repos at http://kaashif.co.uk/code.

Earlier in the year, I was getting curious about version control

Pkgsrc on Slackware

Back in the day, I used to use Slackware. It was the best distro around and all the cool kids used it. Nowadays, it’s rather different: a much lower proportion of people use Slackware. Despite the efforts of Eric and Patrick (and whoever else), Slackware isn’t really all that popular. It’s still a solid distro, though. There is one problem

NetBSD “Review”

Earlier today, I was discussing operating systems and came onto the subject of ease of installation. Which OS had the easiest installer? The obvious answers would tend towards OSs with GUI installers, but is that really easy? Sure, it could be familiar, but there’s a lot more you have to do with GUI installers compared to, say, OpenBSD’s

Learning Racket

I’ve heard a lot of things about Racket (well really, things about many different Lisp dialects), and most of them were good. Recently, I decided to try to decide between Haskell and a Lisp once and for all. I wanted to go for a Lisp–1, since they keep functions and values in the same namespace, which is how it should be. Eventually, after

Emacs is great

I’ve seen many completely stupid articles where people furiously circlejerk over how Vim is the best and nothing will ever come close, but it’s rare that I see anyone write much about Emacs, probably because fewer people use it (or maybe Emacs attracts a different demographic). It’s rare I see an article like

Patching OpenBSD

Recently, I’ve been trying to understand the ins and outs of CVS in order to be able to contribute to OpenBSD without messing up anything. I have sent a few patches to ports@, but anything complex was beyond my abilities until recently.


Recently, I’ve been trying to get away from pre-packaged file sharing solutions (e.g. FreeNAS) and trying to set up the services they provide from scratch. While I obviously won’t be able to write a web GUI or create a whole distro, that simply isn’t necessary. What is necessary is setting up a file share and appropriate read/write permissions.

Haskell isn’t difficult

People like to say that learning Haskell is hard, because a pure, lazy, functional language isn’t something most people are used to. The simple fact of the matter is that most people (nowadays, at least) will be introduced to programming through Python, Javascript or maybe even Java or C#. The problem with learning dynamically typed languages that don’t tell you

How I share a file, simply

Earlier, I saw this article claiming to describe how to share a file “simply” by running Python’s web server module (with either Python 2 or 3). While that may be easy, it’s not simple, and certainly not fast.


The inspiration for this came from this blog post, where the author describes how he uses his computer. While he does use CRUX, a GNU/Linux distro and I use OpenBSD, our workflows are actually surprisingly similar, which can, in part, be attributed to the

Installing OpenBSD on a T61

I’m sure lots of people (dozens, perhaps) have installed OpenBSD on ThinkPad T61s of some description, but with the recent release of OpenBSD 5.5, lots of documentation has become (or already was, and now is even more so) obsolete, like this article

Configuring Mutt

On all of my computers, I like being efficient. That means eliminating everything which uses all that precious CPU time and using applications which are very customisable and configurable. These sorts of applications tend to be text-based, which is, in my eyes, a good thing, since they’ll show you the information you need with a minimum of

Ideas for a project

There is always a lot of buzz around the idea of “learning to program”. While I think it’s very important that children learn logical thinking and problem solving, I also realise that the majority of children, and people in general, would probably not benefit from a very language specific, rote learning based, generally old-fashioned approach to

How this blog works

UPDATE: I now use Hakyll. See http://kaashif.co.uk/about for more. Also, 100% of the information in this blog post is now wrong or outdated.

When I decided I wanted to write a blog, I had to come up with some way of writing posts (in a markup format which isn’t HTML), and serving them somehow.

How not to run a website

After a few months of running a website, there are a few things I have realised about how I ran my server when it was first delivered, and how I run it now. The changes have been, for the most part, for the better. Needless to say, when I first started out, I was clueless, overeager and far too ambitious with my plans for “the next Facebook” or something

Creating a GNU/Linux distro

UPDATE: The project died, it went nowhere.

On nixers.net, the IRC channel of which I spend a bit of time in, there has been a bit of a stir as the community tried to decide on a project to commit to. The idea of creating a distro of some OS came up. A few people wanted a BSD-based distro, but it was decided that the Linux kernel was


When I first started programming, I barely had any idea of what constituted a good text editor, or why I’d want to use some old, texty editor from the 90s which didn’t even have most of the features I took for granted in the IDE I was using at the time. Maybe this had something to do with one of my first languages being Java, which is widely considered an IDE language, but I went through the

My Desktop

Over the years, I’ve used a few different OSes and desktop environments, and the one I use currently is portable to many operating systems, mostly due to the efforts of the writers of i3 over at i3wm.org, but also the standards-compliance of POSIX, meaning that my shell scripts (which you can find here) work on all

Functors in Haskell

Whenever you hear something about Haskell, chances are it sounds arcane and involves lots of complicated and intimidating mathematical language. Well, the truth is that all this talk of ‘endofunctors’ and ‘monoids’ is really unnecessary, if the concept of functors is explained using a simple analogy.

Updating DNS records

When running a website on a residential connection, a problem one might run into is the dynamic IP address usually assigned by one’s ISP. There are a few dynamic DNS services which basically let you have a subdomain (e.g. mydomain.example.com) and let you update it to point to your IP address whenever it changes. At one time, your IP might be, and your domain correctly

What’s a monoid?

If you have spent time on programming or technology boards like /g/ or /r/programming, chances are you might have heard the word “monad” thrown around a lot. You may have even heard the oft misquoted phrase “A monad is a monoid in the class of endofunctors” intended to be a joke, or to scare programmers away from scary functional languages like Haskell. The truth is that monads aren’t

Writing Unix manual pages

There are a few very important things that everyone involved in software (particularly free software) can do to help out. The most important is to file detailed and helpful bug reports, so the developers working on your favourite program can get the problem fixed. Since it is not very hard to write a bug report, and projects generally have their own bug report guidelines, I won’t

Reviving an old ThinkPad

While I did have some old hardware lying around, I had never committed to actually getting that hardware usable. By that, I mean I had never tried to browse the web, read emails and that sort of day-to-day stuff on anything older than a few years. To see if it were really possible, I decided to buy an old ThinkPad (a 760EL from 1995) and see if I could get it working. Before I

Using GNU Stow

stow is a cool little Perl script which basically just creates and deletes symlinks. That sounds pointless, but let me explain with an example. Let’s say you want to install a program using the usual make install, which probably installs into /usr/local, which means it’s separated from the rest of your system, which is managed with a “real” package manager. Unless you’re using a


For a few years now, I have been using Vim to edit config files, program in C, Python, even Lisp (people apparently think that Vim isn’t the best for programming in Lisp). This isn’t because I took a side in the so-called “editor wars”, it’s just because it came preinstalled on the first GNU/Linux system I used, Debian. Over time,

Introduction to C

This tutorial is designed for those who have programmed before, perhaps in a higher level language like Python or Ruby. It’s not too hard to understand for those who are completely inexperienced, but some knowledge of functions, data structures and pointers might help. Most of the low-level stuff will be new to high level programmers, however.

Email is the Future

Often, people look at me oddly when I suggest that they email me something. “Why can’t I just send it to you on Facebook or Skype?” they say. Well, it doesn’t have to be those two media of communication, but it’s usually something like that. When I say often, I also mean that this has only happened on two occasions, so bear that in mind as I make things up about the types of people

How to Wipe a Disk

This article is not only about disk wiping, it will hopefully teach you something about using some GNU command line tools . This tutorial was written on my ThinkPad, which runs Debian, so the output should be pretty similar to what you’d get on Ubuntu, Mint or any other Debian- or Ubuntu-based systems. Basically, if you’re using something

Why I Use FreeBSD

Installing packages from source

Recently, I had SSHed into one of Debian Stable virtual machines I was using as a file server. The main services I was running were FTP, an HTTP server with a directory listing and a Samba server, with shares set up for a few users on my

What is LaTeX?

You probably have not heard of LaTeX before now. If you have, then it is likely that you have no idea what LaTeX is, save for a vague feeling that it relates to documents in some way. By the end of this short post, you will not only know what LaTeX is, but be able to understand why people use it, and what its advantages are. While you probably won’t switch to LaTeX immediately, you might

Web Servers

Imagine you’re a person on some sort of device, using the internet. You see all of these websites and what do you ask? “How can I set up a web server?”, of course. If you did not ask that question, then this guide is not for you. Anyway, down to business. You will need:

How to use GPG

Why am I writing this?

I have looked up “how to use gpg” so many times, on so many websites, and have found every guide to be focused on something I don’t use or worded in such a way that I get confused and revoke all of my keys (that hasn’t actually happened…yet). I thought I’d whip up a quick guide