Re: [Help-bash] prepend to stdin

[Greg Wooledge]

On Tue, Dec 22, 2015 at 02:18:25PM -0600, Brett Kail wrote:
> cat file - | true
> 
> ...but it seems that something waits for a line of input before the
> pipeline somehow ends without error.  What is causing this wait?

The - argument to cat means read stdin.  If you executed this command
in an environment where stdin is a terminal, it's waiting for you to type
a line of input on the terminal.