Pipe stderr to another process

In bash, suppose you want to save stdout to a file, but you want to pipe stderr to another process.
Here's how:

> myprocess 2>&1 > file.out | error_processor

This way of doing things in bash has always confused me, because it seems like you're putting stderr into stdout, then saving stdout in file.out. But it's backwards. Similarly, if you do

> myprocess > file.out 2>&1

you save both stderr and stdout to file.out. Counterintuitive!

How to find out if any command in a bash pipeline failed

set -o pipefail

Add your bash script's own directory to its path

PATH+=:`dirname ${BASH_SOURCE[0]}`

What processes are listening on what ports?

Use lsof.