using tee to output intermediate results to stdout instead of files

sometimes /dev/tty can be used for that...

ls /bin /usr/bin | sort | uniq | tee /dev/tty | grep out | wc

ls /bin /usr/bin | sort | uniq | tee /dev/fd/2 | grep out | wc

On a linux system you can use the the /dev/fd/[num] links like named pipes in many cases. This will duplicate stdout to stderr, which, typically, is your terminal screen, but doesn't need to be.

This command worked for me.

ls /bin /usr/bin | sort | uniq | tee /dev/pts/0 | grep out

You could check what is your terminal using the command tty and replace the tee to redirect the output to that terminal.

References

https://stackoverflow.com/a/18025293/1742825