How can I pipe bash output to a file and to the terminal at the same time?

Question

This is a really basic question, but I couldn't find it asked this basically in an existing question, so please flag this if it's been answered before.

I want to pipe stderr from a bash command to a file, but not prevent it from being displayed on the terminal during execution.

More specifically, I have this .sh file:

nslookup MadeUpName
nslookup MadeUpName2
nslookup MadeUpName3

and I'm doing this:

. ./myScript.sh 2>errors.txt

This works to pipe error messages to errors.txt, but now I can't see the errors in the terminal as they happen.

Answer 1

You can use tee for displaying error and writing to an error file:

myScript.sh 2> >(tee error.log; exit)

If you want further information about this technique, see this page.