Isn't there a way to tell bash not to buffer an output descriptor? I know you can do it with ioctl inside C/C++.
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Steven S. Critchfield Sent: Wednesday, February 19, 2014 12:02 PM To: [email protected] Subject: Re: [nlug] Weird CentOS 6 Bash/Grep issue ----- Original Message ----- > OK, the mystery shifts. If I don't setup the "real time" (sub-level > child?) > with the '-f' and just do a same level operation such as: > > tail -500 /var/log/pfsense | egrep -e '\.25\:' -e '\.465\:' -e > '\.587\:' | grep -v '192\.168\.0\.71' > > it works as desired! > > Something with the child process of the tail that is continuously > reading the target(s) and feeding them to STDOUT in real time doesn't > like that fork to the 2nd grep. I tried encapsulating the tail in '(' > and ')' but no go. What you are seeing is really simple. It is output buffering. Since the tail above sends out a block and then EOF, the first grep can filter and EOF, then the final grep can filter and EOF flush. In the other, you are waiting for a buffer fill before it will start displaying. -- Steven Critchfield [email protected] -- -- You received this message because you are subscribed to the Google Groups "NLUG" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nlug-talk?hl=en --- You received this message because you are subscribed to the Google Groups "NLUG" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out. -- -- You received this message because you are subscribed to the Google Groups "NLUG" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nlug-talk?hl=en --- You received this message because you are subscribed to the Google Groups "NLUG" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
