I picked this book by mistake, assuming that it was going to be a technically detailed book in line with the Advanced Programming in the Unix Environment book written by the late Richard Stevens, it turned out to be much more high level than that but I was not disappointed, It’s been a pleasure to read whilst travelling over the last month.
The book is 20 chapters split across four parts (context, design, implementation, community) with commentary from some big names of the UNIX world. There are lots of great advice in the book but I would look at what’s now available in regards to software today if I was looking to implement something. It does explain why lots of software relies on some common (and heavy weight?) components. Let me explain, long ago I was unaware that packages for the -current branch of OpenBSD were being built, whenever I grudgingly tried a new snapshot I went through & built my packages from the ports tree after a fresh install, then something would depend on XML related components & then pull in a bunch of things which would involve building ghostscript, on a Sun Blade 100, between Firefox & ghostscript, 24 hours would easily be wasted, I now understand that all that wasted time was thanks to someone taking the advice of ESR on how to prepare documentation for a software project.
Besides the dubious software recommendation (11-year-old book?) everything is explained in a clear manner that’s very easy to read.
Rule of Robustness: Robustness is the child of transparency and simplicity.
Rule of Generation: Avoid hand-hacking; write programs to write programs when you can.
Rule of Optimization: Prototype before polishing. Get it working before you optimize it.
Rule of Diversity: Distrust all claims for “one true way”.
Rule of Extensibility: Design for the future, because it will be here sooner than you think.
The Pragmatic Programmer articulates a rule for one particular kind of orthogonality that is especially important. Their “Don’t Repeat Yourself” rule is: every piece of knowledge must have a single, unambiguous, authoritative representation within a system. In this book we prefer, following a suggestion by Brian Kernighan, to call this the Single Point Of Truth or SPOT rule.
The book is critical of Microsoft & their approach to software, explaining some of the design decisions (some inherited from the world of VMS).
From a complexity-control point of view, threads are a bad substitute for lightweight processes with their own address spaces; the idea of threads is native to operating systems with expensive process-spawning and weak IPC facilities.
the Microsoft version of CSV is a textbook example of how not to design a textual file format.
Criticisms of MacOS are of version 9 and prior which don’t really apply to OS X e.g. single shared address space. There are explanations of why things are such in the world of Unix and lots of great advice.
The ’rc’ suffix goes back to Unix’s grandparent, CTSS. It had a command-script feature called “runcom”. Early Unixes used ’rc’ for the name of the operating system’s boot script, as a tribute to CTSS runcom.
most Unix programs first check VISUAL, and only if that’s not set will they consult EDITOR. That’s a relic from the days when people had different preferences for line-oriented editors and visual editors
When you feel the urge to design a complex binary file format, or a complex binary application protocol, it is generally wise to lie down until the feeling passes.
One of the main lessons of Zen is that we ordinarily see the world through a haze of preconceptions and fixed ideas that proceed from our desires.
Doug McIlroy provides some great commentary too
As, in a different way, was old-school Unix. Bell Labs had enough resources so that Ken was not confined by demands to have a product yesterday. Recall Pascal’s apology for writing a long letter because he didn’t have enough time to write a short one. —Doug McIlroy
I’d recommend the book for anyone involved with computers and not necessarily involved with Unix or open source variants/likes. The author does a great job of explaining the theory of an approach to developing software and the operating it typically runs on, It’s accessible, easy to read and doesn’t require a computer to work through. You may need one however if you want to read it online for free.
My ideal for the future is to develop a filesystem remote interface (a la Plan 9) and then have it implemented across the Internet as the standard rather than HTML. That would be ultimate cool. —Ken Thompson