GNU bug report logs - #27368
Minor concern: Confusing tail warning

Previous Next

Full log

View this message in rfc822 format

From: Charlie Hagedorn <charlie.hagedorn <at> gmail.com>
To: 27368 <at> debbugs.gnu.org
Subject: bug#27368: Minor concern: Confusing tail warning
Date: Wed, 14 Jun 2017 16:03:07 -0700

[Message part 1 (text/plain, inline)]

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

[Message part 2 (text/html, inline)]

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.