Redirect stderr to terminal and also file in bashAnswer #1 100 %
Yes, the tee command allows you to direct output to one or more files, as well as stdout.
As you pointed out in a comment, this doesn't work by itself because of the exec command.
This should do what you want:
exec 3>&1 1>test.log echo "Check if this line is going to test.log" exec 1>&3 3>&- echo "Maybe this should go to stderr" | tee -a test.log >> /dev/stderr
I got the information about the way to restore stderr by properly setting up the original exec, from here, and combined it with tee.