Date: Wed, 20 Nov 2013 23:38:44 +0100 From: Dimitry Andric <dim@FreeBSD.org> To: Florent Peterschmitt <florent@peterschmitt.fr> Cc: freebsd-stable stable <freebsd-stable@freebsd.org> Subject: Re: tcpdump | grep pattern > capture nothing got Message-ID: <966AFB1F-D273-4754-96AC-01298FBF6F42@FreeBSD.org> In-Reply-To: <528D0302.7090906@peterschmitt.fr> References: <528D0302.7090906@peterschmitt.fr>
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--Apple-Mail=_A19706EC-9417-4AC2-9BA5-A901F8CCC40F Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 On 20 Nov 2013, at 19:44, Florent Peterschmitt <florent@peterschmitt.fr> = wrote: > I use FreeBSD 10.0-BETA3 amd64, upgraded from 9.2-RELEASE with > freebsd-update. >=20 > I was capturing with tcpdump and doing some grep on it: >=20 > # tcpdump -li nfe0 port 53 | grep Refused > capture.txt >=20 > I was surprised that capture.txt is totally empty. If I don't redirect > the output, then it writes what I need on stdout. Try grep --line-buffered instead (which incurs a performance penalty, but you probably don't care in this case). BSD grep also supports this option. -Dimitry --Apple-Mail=_A19706EC-9417-4AC2-9BA5-A901F8CCC40F Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP using GPGMail -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.22 (Darwin) iEYEARECAAYFAlKNOf0ACgkQsF6jCi4glqNHLgCgsWLN3cdAo6+EOkd/x791kZgz SZ0AoMWrGzH6pjILQBtBwrDYJpdQ1LiT =lku9 -----END PGP SIGNATURE----- --Apple-Mail=_A19706EC-9417-4AC2-9BA5-A901F8CCC40F--
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