I use tee to save log files from long running programs. The chatter goes to stdout, and informs me about progress. But the tee also saves the chatter, so I can review it if something goes wrong.
You could get a similar effect in other ways (e.g., tail -f, or terminal scrollback), but I find tee is convenient.
long_running_thing | tee long_running_thing_stdout
and want to see the first few lines of output before going to do something else. The pipe causes buffering on stdout, though, so I have to sit there until 4k of output has come out on stdout.
You could get a similar effect in other ways (e.g., tail -f, or terminal scrollback), but I find tee is convenient.