Thursday 28 November 2019 The Forest Road Reader, No 2.40 : STinC++ - Chapter Two Wrap Up

Each program in chapter one was progressively a little more complex than the one before. This is not the case in Chapter Two, where the various programs form more of a loose map of the territory. Here we have a program that replaces many characters with a single character, while over there we have a program that might produce many lines of output for a single line of input, and so on.

This chapter is, without directly saying so, pretty explicitly about the Unix philosophy. While Unix systems (or at least Unix-ish systems) are basically the substrate of most modern computing (yes, even if you’re a Windows, Android, or iOS user) in 1981, when Software Tools in Pascal was published, there were “800 systems …​ in use outside [Bell Labs]”. Kernighan and Pike have to take time to describe what’s now commonplace - combining small programs with pipelines, text as common currency, indeed the whole idea of software tools and of the programmer as tool user.

When I first read Software Tools in Pascal, I’d just started my first substantial job on a Unix system (in fact four Unix systems, all slightly different) and I was only passingly familiar with a handful of command line tools. The idea that these small programs not only did simple things, but could be combined like some kind of giant tokusatsu robot to do very powerful things was really quite startling. It certainly changed, and continues to influence, how I think about programming and I have no doubt I’m a better programmer for that. I’m not sure I’ll ever touch the heights achieved by my friend Thomas in his masterful He Sells Shell Scripts To Intersect Sets, in which he combines standard Unix tools to do full on computer science, but I’m nearer than I otherwise would be.

Next up, files!