For interactive use, I would like to point out that even better than this use of cat is less. If you pipe less into something then it forgets it’s interactive behaviour and works like cat on a single file. So:

  $ less foo | bar

Is similar too:

  $ bar < foo

Except that less is typically more clever than that and might be more like:

  $ zcat foo | bar

Depending on the file type of foo.