paste without temporary files in Unix

Question

I\'m trying to use the Unix command paste, which is like a column-appending form of cat, and came across a puzzle I\'ve never known how to solve in Unix.

How can you use

Answer 1

Use named pipes (FIFOs) like this:

mkfifo fA
mkfifo fB
progA > fA &
progB > fB &
paste fA fB
rm fA fB

The process substitution for Bash does a similar thing transparently, so use this only if you have a different shell.