The Creation of the UNIX* Operating System: Creating a programming philosophy from pipes and a tool box

This is an archival site

Creating a programming philosophy from pipes and a tool box

As technically neat as the accomplishment was, when Thompson created pipes, he also put something else into UNIX -- a philosophy.

As McIlroy described it, "the philosophy that everyone started to put forth was 'Write programs that do one thing and do it well. Write programs to work together. Write programs that handle text streams, because that is a universal interface.'"

"All of these ideas, which add up to the tool approach, might have been there in unformed way prior to pipes, but they really came in afterwards," he said.

Kernighan agreed. He noted that while input/output direction predates pipes, the development of pipes led to the concept of tools -- software programs that would be in a "tool box," available when you need them.

He noted that pipes made software programs somewhat analogous to working with Roman numerals instead of Arabic numerals. "It's not that you can't do arithmetic," he said, "but it is a bear."

"I remember the preposterous syntax, the ">,>" or whatever the syntax that everyone came up with, and then all of a sudden there was the vertical bar ( | ) and just everything clicked at that point," he said. The bar was the syntax that made pipes work: who | cat | grep.

"And that's, I think, when we started to think consciously about tools, because then you could compose things together....compose them at the keyboard and get 'em right every time."

Next: 'What you think is going on, is going on'