bash - How run a command, show stderr on screen, and at the same time, save stderr in a file

Question

I want to run a command, show stderr on screen and, at the same time, save stderr in a file.

question from:https://stackoverflow.com/questions/65868663/how-run-a-command-show-stderr-on-screen-and-at-the-same-time-save-stderr-in-a

Answer 1

In bash (or zsh), you can do this by redirecting stderr to tee via a process substitution:

somecommand 2> >(tee errors.log)