It's probably coming from buffering on the stdio between the two greps.
The tail does away with buffering on the pipe between it and the first
grep, but the two greps don't , so you have to wait for the buffer to fill
before a chunk gets spit out.
On Fri, Jan 28, 2000 at 09:47:16AM -0600, Austin Bingham wrote:
> The wierd part of that is the blocky output from two pipes. Just as an
> experiment, have you tried running the "two grep" command in a different
> terminal or possibly shell? I would be interested to know where that
> behavior is coming from.
>
> Austin Bingham
> Laboratory for Intelligent Processes and Systems
> University of Texas at Austin
> [EMAIL PROTECTED]
> -----Original Message-----
>
>
> >To answer your question, grep, egrep, fgrep do not support negative
> >lookahead assertion. Perl and tcl (and prob others) do. Read man perlre
> >for more on that. (It basically lets you specify in one regex to match
> ><expression> iff <other expression> doesn't match. I regularly pipe
> >through two greps, often with the -v flag and have no problems. I doubt
> >it's a tail or grep problem iow.
> >
> >jason h fowler wrote:
> >>
> >> hey ... i'm trying to filter the output of tail ...
> >> i know to show everything that says "something" all i have to do is pipe
> >> the output of tail into grep ... like:
> >> tail -f /etc/httpd/logs/access_log | grep something
> >> and i know to have everything show except for "somethingelse" i do:
> >> tail -f /etc/httpd/logs/access_log | grep -v somethingelse
> >> but can i, using one grep command, show only "something" but not
> >> "somethingelse" ? ...
> >> i've tryed:
> >> tail -f /etc/httpd/logs/access_log | grep someting | grep -v
> >> somethingelse
> >> but that spits out big hunks every 1-2 minutes ... it doesn't actually
> >> follow it real time ... and yes i have read the man page for it ... but
> >> i didn't see anything to say about combining what i want to search for
> >> and what i want to skip ... if it's painfully obvious, please help me
> >> out ... sometimes i'm pretty stupid ... (c:
> >> thanx a lot,
> >> jason fowler
> >---------------------------------------------------------------------------
> >Send administrative requests to [EMAIL PROTECTED]
>
> ---------------------------------------------------------------------------
> Send administrative requests to [EMAIL PROTECTED]
--
_____________________ _ _ _________________________
Michael Rice |_| Collective |_| http://www.colltech.com
[EMAIL PROTECTED] |_ Technologies _| 8009464646/1481714 pager
Consultant [] [] "The Power Of Many Minds"
---------------------------------------------------------------------------
Send administrative requests to [EMAIL PROTECTED]
