BASH> Redirect output to standard out AND file

Eventually in scripting you are likely to want to output to both the screen (standard out) and to a file. This makes it convenient to see whats getting “logged” without needing the extra step of cat’ing the file.

For example:

ls -al | tee ls_al_result.txt

This will give you your normal ‘ls -al’ results but also feed them to your new file.