Ask Dave Taylor: Tech and Business


What does the Unix command "cat -" do?

Hello I would like to know the what exactly does cat - mean in Unix? I was recently reading through an article that mentioned this command and couldn't understand what it did.

"cat" is the 'concatenate' program and its purpose is to display the contents of one or more file. Add the '-' flag, however, and you have it display the content of "standard input" or "stdin": in a pipe like:
tail myfile | cat -

It's basically a null operation, since this is no different than doing...