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A Very Brief History of Unix
The UNIX operating system was developed around 1969 at Bell Laboratories by
computer scientists, Dennis Ritchie, Ken Thompson, and Brian Kernighan. This
new operating system came to embody quite a few innovative concepts that
remain a hallmark of modern day UNIXes. Such concepts include its heirarchical
file system, process handling, tool-box approach to system utilities,
pipes and redirection, and multi-user nature.
- Heirarchical Filesystem
- Unix has a clean heirarchical filesystem, with only one root directory,
called "/", in which all other directories are contained. The filesystem
can be (and almost always is) made of up various devices, they are just
"mounted" into various places in the one filesystem.
- Process handling
- Every program running on a Unix system has its entry in the system's
process list, and is assigned a unique process id (PID). This includes
users' processes as well as the system processes and server processes
(typically called daemons). Any user can request a list of their or the
system's processes.
- Tool-Box approach
- Most programs in Unix are designed as small black-box tools. They each
do one job, and do that job well, without becoming bloated by too many
features, bells, and whistles.
- Pipes and Redirection
- Pipes and redirection, covered here,
build on the tool-box approach of Unix, by making a clean interface for
tools to be plugged into each other. Pipes work like the conveyor belt in
a factory's assembly line, taking data from one tool station to the next.
Links
A lot of people have written much better histories and introductions to
UNIX than I, so I'll just link to them:
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