Pipe Logic – Simulating circuits in the Unix shell (2011)

This article is great for having both a nontrivial FIFO and a nontrivial circuit discussion in the same guide—both things for which I've had difficulty finding good self-contained tutorials.

> "Somewhere at that time I talked of a macro as a 'switchyard for data streams,' and there's a paper hanging in Brian Kernighan's office, which he dredged up from somewhere, where I talked about screwing together streams like a garden hose"

> "And over a period from 1970 to 1972, I'd from time to time say, 'How about making something like this?', and I'd put up another proposal, another proposal, another proposal. And one day I came up with a syntax for the shell that went along with the piping"

> "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"

https://web.archive.org/web/20001214172500/http://www.bell-l...

E.g. stderr had not been implemented from the start - http://minnie.tuhs.org/pipermail/tuhs/2017-September/010406....

So I doubt it

[1] http://www.softpanorama.org/Scripting/pipes.shtml

[2[ https://www.bell-labs.com/usr/dmr/www/pdfs/man21.pdf

Also, ; between commands is the equivalent of running each command on a seperate line (command independent of previous command exit status).

& = run in background

; = execute sequentially

&& = AND operator

|| = OR operator

! = NOT operator

&&-|| = ANDOR operator

{} = combine command operator

() = precedence operator

=~ = regex operator

http://www.gnu.org/software/bash/manual/bashref.html#Conditi...