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]
