inux命令设计器的设计外文翻译.doc

History of Unix After four decades of use, computer scientists continue to regard the Unix operating system as one of the most powerful and elegant systems in existence. Since the creation of Unix in 1969, the brainchild of Dennis Ritchie and KenThompson has become a creature of legends, a system whose design has withstood the test of time with few bruises to its name. Unix grew out of Multics, a failed multiuser operating system project in which Bell Laboratories was involved.With the Multics project terminated, members of Bell Laboratories’ Computer Sciences Research Center found themselves without a capable interactive operating system. In the summer of 1969, Bell Lab programmers sketched out a filesystem design that ultimately evolved into Unix.Testing its design,Thompson implemented the new system on an otherwise-idle PDP-7. In 1971, Unix was ported to the PDP-11, and in 1973, the operating system was rewritten in C—an unprecedented step at the time, but one that paved the way for future portability.The first Unix widely used outside Bell Labs was Unix System, Sixth Edition, more commonly called V6. Other companies ported Unix to new machines.Accompanying these ports were enhancements that resulted in several variants of the operating system. In 1977, Bell Labs released a combination of these variants into a single system, Unix System III; in 1982, ATT released System V. 1 The simplicity of Unix’s design, coupled with the fact that it was distributed with source code, led to further development at external organizations. The most influential of these contributors was the University of California at Berkeley. Variants of Unix from Berkeley are known as Berkeley Software Distributions, or BSD. Berkeley’s first release, 1BSD in 1977, was a collection of patches and additional software on top of Bell Labs’ Unix. 2BSD in 1978 continued this trend, adding the csh and vi utilities, which persist on Unix systems to this day. The first standalone Berkeley Unix was 3BSD