Unix的影响和哲学 Unix是第三次工业革命中计算机软件领域最具代表性的产物。在这近40年中,由Unix造成的影响是最有深远意义的。就我看来,Unix为软件领域带来了至少以下有积极的东西,由这些东西所引发的直接或间接的事物更是举不胜数。 软件开发的若干哲学和思想。 全民参与推动软件,代码共享的模式。 开启了黑客文化和开源项目。 免费和商业的完美结合的Linux。 C语言,而后发展的C++,Java等等类C的语言和脚本。(参看《C语言的演变史》) TCP/IP,其的Socket编程已成为今天通用的网络编程主流。(参看《到处都是Unix的胎记》) 不能不说,AT&T虽然发展了Unix,但今天Unix的混乱的局面也和AT&T 有着直接原因。但反过来说,如果没有AT&T的反面教材,今天的GNU/Linux很有可能也不会出现。AT&T究竟是限制了Unix的发展,还是以反面示例促进了Unix社区,已不好评说。今天,软件是商业化好还是开源好的争论还在继续,纵观这几十年来Unix的历史,Linux的划时代地出现。相信你会得出自己的结论。不管怎么样,Unix的经历对计算机领域贡献的不单单是技术,他给我们提供了丰富而生动的教材。特别是Unix引发的哲学,让今天的我们依然受益不浅。 说到Unix为我们所带来的软件开发的哲学,我必需要说一说。Unix遵循的原则是KISS(Keep it simple, stupid)。在http://en。wikipedia。org/wiki/Unix_philosophy 上有很多的基本上大同小异的Unix哲学,都是很经典的。 Doug McIlroy 是认为UNIX的哲学是这样的:三条哲学,简明扼要,就是这三条哲学贯穿着整个Unix世界。尤其是第一条“do one thing and do it well”真是相当精彩! Write programs that do one thing and do it well。 Write programs to work together。 Write programs to handle text streams, because that is a universal interface。 只要是Unix的程序员,他们会比别的程序员在任何时候都会不停地强调着这三条哲学。 而《The Art of Unix Programming》总结了下面这些哲学,都是至理名言啊。 Rule of Modularity: Write simple parts connected by clean interfaces。 Rule of Clarity: Clarity is better than cleverness。 Rule of Composition: Design programs to be connected to other programs。 Rule of Separation: Separate policy from mechanism; separate interfaces from engines。 Rule of Simplicity: Design for simplicity; add complexity only where you must。 Rule of Parsimony: Write a big program only when it is clear by demonstration that nothing else will do。 Rule of Transparency: Design for visibility to make inspection and debugging easier。 Rule of Robustness: Robustness is the child of transparency and simplicity。 Rule of Representation: Fold knowledge into data so program logic can be stupid and robust。 Rule of Least Surprise: In interface design, always do the least surprising thing。 Rule of Silence: When a program has nothing surprising to say, it should say nothing。 Rule of Repair: When you must fail, fail noisily and as soon as possible。 Rule of Economy: Programmer time is expensive; conserve it in preference to machine time。 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。 X Windows 的设计者 Mike Gancarz 给出了下面九条哲学思想 Small is beautiful。 Make each program do one thing well。 Build a prototype as soon as possible。 Choose portability over efficiency。 Store data in flat text files。 Use software leverage to your advantage。 Use shell scripts to increase leverage and portability。 Avoid captive user interfaces。 Make every program a filter。 在今天,这种思想依然被传承着,在影响着世界上各个角落的每一个程序员。 |