Date: Wed, 4 Aug 2010 21:22:09 +0400 From: pluknet <pluknet@gmail.com> To: Lars Engels <lars.engels@0x20.net> Cc: poyopoyo@puripuri.plala.or.jp, Alexandre Sunny Kovalenko <gaijin.k@ovi.com>, Gabor Kovesdan <gabor@freebsd.org>, current@freebsd.org Subject: Re: bsdgrep does not work with tail -f | grep combination Message-ID: <AANLkTin6-N-_HKvqmpR%2Bh1txpp-raUYV1btNNnYgGrVu@mail.gmail.com> In-Reply-To: <20100804162809.GE59909@e.0x20.net> References: <86eiefhalp.wl%poyopoyo@puripuri.plala.or.jp> <4C585E44.5030608@FreeBSD.org> <1280933468.2752.2.camel@RabbitsDen> <20100804162809.GE59909@e.0x20.net>
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On 4 August 2010 20:28, Lars Engels <lars.engels@0x20.net> wrote: > 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@puripuri.plala.or.jp escreveu: >> > > Hi, >> > > >> > > It seems bsdgrep does not work when piped from tail -f. >> > > I'm running r210728. >> > > >> > > term0$ jot 10> =A0/tmp/1 >> > > term0$ tail -f /tmp/1 | grep 0 >> > > [no output] >> > > >> > > otherterm$ jot 10>> =A0/tmp/1 >> > > [no output to term0] >> > > >> > > =3D=3D=3D=3D=3D >> > > >> > > with GNU grep: >> > > >> > > term0$ tail -f /tmp/1 | gnugrep 0 >> > > 10 >> > > otherterm$ jot 10>> =A0/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 yo= u >> > 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. > By the way, egrep from 4.4BSD-Alpha used read(2) with 8k blocks. I justed checked, it works with tail -f. --=20 wbr, pluknet
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