Re: piping tail -f through cut

[Pádraig Brady]

Bob van Loosen wrote:
> Hi everyone,
> 
> Whenever I do this:
> 
> tail -f  /var/log/kern.log | cut -f 8- -d " " | dd bs=1
> 
> I get no output, but when I do this:
> 
> tail -f  /var/log/kern.log | cut -f 8- -d " "
> 
> I do get output, I'm using coreutils 5.97 on Ubuntu 7.10 64 bit.

I've documented that exact case here:
http://www.pixelbeat.org/programming/stdio_buffering/

There's a patch for `cut` there,
which demonstrates how to add this functionality to coreutils.

Personally I think it would be great to add the buffering control
to glibc, so that most applications would benefit.
But Ulrich Drepper <sarcasm>in his usual amiable style</sarcasm>
suggested this was a silly idea.

Pádraig.