Re: bsdgrep does not work with tail -f | grep combination

On Wed, Aug 04, 2010 at 10:51:08AM -0400, Alexandre Sunny Kovalenko wrote:
> On Tue, 2010-08-03 at 20:21 +0200, Gabor Kovesdan wrote:
> > Em 2010.08.03. 19:25, poyopoyo_at_puripuri.plala.or.jp escreveu:
> > > Hi,
> > >
> > > It seems bsdgrep does not work when piped from tail -f.
> > > I'm running r210728.
> > >
> > > term0$ jot 10>  /tmp/1
> > > term0$ tail -f /tmp/1 | grep 0
> > > [no output]
> > >
> > > otherterm$ jot 10>>  /tmp/1
> > > [no output to term0]
> > >
> > > =====
> > >
> > > with GNU grep:
> > >
> > > term0$ tail -f /tmp/1 | gnugrep 0
> > > 10
> > > otherterm$ jot 10>>  /tmp/1
> > > [on term0]
> > > 10
> > > 10
> > >    
> > I've checked on 8.0 and GNU grep doesn't output anything either for me. 
> > If you use tail -f, you will enter more lines and end it with EOF, won't 
> > you? And then BSD grep will process the input and print out matches. I 
> > don't think it's bad behaviour in itself but if you can explain why you 
> > think it's bad I'm willing to change it.
> > 
> I am not sure it is specific to the GNU grep -- below is the example
> from AIX 5.3:

[...]

Same on Solaris, so this is not a GNU feature.