The T-Junction

The T-Junction

This is a special type of pipe similar to a T pipe junction in real life. This is used to redirect incoming data in a pipe to more than one place.

T-Junction in piping

The tee command is used to form a T-junction. It takes its input from stdin and writes the same thing to stdout as well as to another file at the same time. Consider the same example of the who command. If you want to display the output of the who command at the terminal as well as save it in whofile for future use.
The command line and result will be as follows :
$ who | tee whofile