Run once, run often… — Most of the time, having a computer do more than one thing at a time is a good thing. But if you write shell scripts, you’ll eventually write something that should only run one copy at a time. For example, I have a script that mounts some remote directories when…

Who wins the Internet race? — Hypothetical situation: you are about to send a file remotely to the cloud (wherever that is). You have a choice of two servers, but you don’t know which one to pick. The truth is, that’s a complicated question and there are many ways you could profile it. However, one simple…

Sometimes good things come to those who wait One of my pet peeves about software is how every program I install seems to think that it is so important that it needs to load up and start running the second my computer is up. Sure, sometimes that’s true. …

Time to get dirty with memory paging — Your computer lies to you all the time and that’s a good thing. In this article, I’m going to tell you how your computer lies to you all the time about how much memory it has and why that’s a good thing. I’ll also tell you how to tune some…

Stop hogging my system Baloo! — I wrote about using Cgroups to limit disk usage from greedy Linux programs a while back. In particular, KDE’s baloo file index program is incredibly bad when you do a clean install. Sure, if you have a few hundred files in your home directory it isn’t bad. But I have…

An Ordinary WebCam will do the Trick Linux is — usually — designed to be flexible. Have you ever wondered how programs that need your password work? Obviously, they can’t all check your password. Besides, what about things like fingerprint readers or hardware keys? It is analogous to the situation…

Don’t be afraid to inspire, plan, replan, and go one day at a time… — Americans are maybe the worst about this, but we often don’t know about people who are quite famous in other countries. One of my New York friends, for example, did his master’s paper in English on the national poet of Turkey, Mehmet Akif Ersoy. Never heard of him. You might…

Love them or hate them, you can make functions take a variable number of arguments in Python — Depending on how you learned to program, you may love functions that take a variable number of arguments, or you may hate them. But it is hard to deny that there are cases where they make sense. If you started out with C, you probably never minded variable argument lists…

A better way to loop As a very old C programmer, I find, sometimes, that I am writing C in whatever language I’m using. If you have this problem, you should look at other ways to more efficiently code in other languages like Python. For example, one of the calls…