Unix Philosophy

Note: This page is a stub / incomplete.

Unix philosophy has been declared dead countless times by newer generations, but they always end up re-discovering it in the end.

Learn this concepts, try to keep them in mind and your life will be simpler and easier.

Eric Steven Raymond's 17 rules - The Art of Unix Programming (2003)


  1. Rule of Modularity: Write simple parts connected by clean interfaces.

  2. Rule of Clarity: Clarity is better than cleverness.

  3. Rule of Composition: Design programs to be connected to other programs.

  4. Rule of Separation: Separate policy from mechanism; separate interfaces from engines.

  5. Rule of Simplicity: Design for simplicity; add complexity only where you must.

  6. Rule of Parsimony: Write a big program only when it is clear by demonstration that nothing else will do.

  7. Rule of Transparency: Design for visibility to make inspection and debuggingeasier.

  8. Rule of Robustness: Robustness is the child of transparency and simplicity.

  9. Rule of Representation: Fold knowledge into data so program logic can be stupid and robust.

  10. Rule of Least Surprise: In interface design, always do the least surprising thing.

  11. Rule of Silence: When a program has nothing surprising to say, it should say nothing.

  12. Rule of Repair: When you must fail, fail noisily and as soon as possible.

  13. Rule of Economy: Programmer time is expensive; conserve it in preference to machine time.

  14. Rule of Generation: Avoid hand-hacking; write programs to write programs when you can.

  15. Rule of Optimization: Prototype before polishing. Get it working before you optimize it.

  16. Rule of Diversity: Distrust all claims for “one true way”.

  17. Rule of Extensibility: Design for the future, because it will be here sooner than you think.

Original Unix philosophy - Bell System Technical Journal (1978)

  1. Make each program do one thing well. To do a new job, build afresh rather than complicate old programs by adding new "features".
  2. Expect the output of every program to become the input to another, as yet unknown, program. Don't clutter output with extraneous information. Avoid 1. stringently columnar or binary input formats. Don't insist on interactive input.
  3. Design and build software, even operating systems, to be tried early, ideally within weeks. Don't hesitate to throw away the clumsy parts and rebuild them.
  4. Use tools in preference to unskilled help to lighten a programming task, even if you have to detour to build the tools and expect to throw some of them out after you've finished using them.

Summary - A Quarter-Century of Unix (1994)

  1. Write programs that do one thing and do it well.
  2. Write programs to work together.
  3. Write programs to handle text streams, because that is a universal interface.