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

Holy moly, I recent found out that in some instances, you can get your process substitution to work if you set the following inside of a bash script (should you need to):

set +o posix

http://www.linuxjournal.com/content/shell-process-redirection

From link: "Process substitution is not a POSIX compliant feature and so it may have to be enabled via: set +o posix" I was stuck for many hours, until I had done this. Here's hoping that this additional tidbit will help.

Answer 2

Works in all shells.

{
progA
progB
} | paste

Answer 3

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.

Answer 4

You do not need temp files under bash, try this:

paste <(./progA) <(./progB)

See "Process Substitution" in the Bash manual.