Hi!

Thank you for maintaining such useful and reliable tools.

Today I came across an unexpected warning in tail. The warning is intended to handle this case:

[:~]$ tail -f

tail: warning: following standard input indefinitely is ineffective

which is both important and fun.

Today, however, I was surprised to see it appear in this context:

[:~]$ tail -f < /dev/ttyUSB0 > data.dat

tail: warning: following standard input indefinitely is ineffective

The warning was confusing and perhaps inappropriate, as this call actually *does* something, and is very effective at doing what I want; streaming the port's output into data.dat.

(Importantly, for reasons I don't yet understand, tail -f /dev/ttyUSB0 > data.dat does not reliably tail the port; it redirects only one line of output instead of a continuous stream).

System is Debian Jessie -- coreutils v8.23-4.

Thanks!

Charlie