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CHAPTER 1 THE HISTORY OF UNIX, GNU, AND LINUX

are GNU tools. As such, some people prefer to use the phrase “GNU/Linux” to describe the com-

bination of GNU userspace plus Linux kernel. For the purposes of this book, the goal is to be

technically accurate while avoiding overly political zeal. RedHat Linux is what RedHat calls its dis-

tribution, so it is referred to as RedHat Linux. Debian GNU/Linux prefers to acknowledge the GNU

content so we will, too, when referring speciﬁ cally to Debian. When talking about the Linux kernel,

we will say “Linux”; when talking about a GNU tool we will name it as such. Journalists desper-

ate for headlines can occasionally dream up a far greater rift than actually exists in the community.

Like any large family, it has its disagreements — often loudly and in public — but we will try not to

stoke the ﬁ re here.

Unix was designed with the assumption that it would be operated by engineers;

that if somebody wanted to achieve anything with it, he or she would be prepared

to learn how the system works and how to manipulate it. The elegant simplicity of

the overall design (“everything is a ﬁ le,” “do one thing and do it well,” etc.) means

that principles learned in one part of the system can be applied to other parts.

The rise in popularity of GNU/Linux systems, and in particular, their relatively widespread use on

desktop PCs and laptop systems — not just servers humming away to themselves in dark datacen-

ters — has brought a new generation to a set of tools built on this shared philosophy, but without

necessarily bringing the context of history into the equation.

Microsoft Windows has a very different philosophy: The end users need not concern themselves

with how the underlying system works, and as a result, should not expect it to be discernable, even

to an experienced professional, because of the closed-source license of the software. This is not

a difference in quality or even quantity; this is a different approach, which assumes a hierarchy

whereby the developers know everything and the users need know nothing.

As a result, many experienced Windows users have reviewed a GNU/Linux distribution and found

to their disappointment that to get something conﬁ gured as it “obviously” should be done, they had

to edit a text ﬁ le by hand, or specify a certain parameter. This ﬂ exibility is actually a strength of the

system, not a weakness. In the Windows model, the user does not have to learn because they are not

allowed to make any decisions of importance: which kernel scheduler, which ﬁ lesystem, which win-

dow manager. These decisions have all been made to a “one size ﬁ ts most” level by the developers.

SUMMARY

Although it is quite possible to administer and write shell scripts for a GNU/Linux system without

knowing any of the history behind it, a lot of apparent quirks will not make sense without some appre-

ciation of how things came to be the way they are. There is a difference between scripting for a typical

Linux distribution, such as RedHat, SuSE, or Ubuntu, and scripting for an embedded device, which

is more likely to be running

busybox than a full GNU set of tools. Scripting for commercial Unix is

slightly different again, and much as a web developer has to take care to ensure that a website works

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