On Fri, Feb 13, 2009 at 07:26:50AM -0300, Paulo Brito wrote: > > > > If you want to just what's changed in the log file since the last time > > you connected, look at the package logtail. > > > > For example you might run this command: > > > > while :; do nc -l -p 5558 -c "logtail /var/log/syslog"; done > > > > This would have nc exit when it's done dumping /var/log/syslog and the > > next time someone connects it should pick up where it left off. > > > > Regards, > > Tod Detre > > > > > Nice tip, Tod. But the idea was keeping a connection open, to get client > informed by server that something happened. > > Anyway, looking in netcat sources yesterday I found the reason of that > behavior. It uses the "execl" system call to run -e program (the version I > looked don't have -c anymore). Execl just substitute the current process > with the new one, and execl never returns! So netcat sets up the network > connections and pipes and go off the scenes. And so, netcat got no chances > of killing the -e program. That's the reason why when -e program exits, the > connection is gone. In my specific case, thare's another issue: tail -f dont > care about stdin and never returns. > > Maybe someday a new feature appers in netcat: run -e/-c program in a fork or > something, so netcat can still have the control.
If you're running this as a service, you might want to just set it up in inetd. Assuming you're using inetd and not xinetd or others, your line might look something like this: 5558 stream tcp nowait root /usr/bin/tail tail -F /var/log/syslog I haven't tried that, nor have I tested that it does what you want. But it may be worth a shot. I've never tried putting a command that wasn't designed for inetd in its config before. If you try it I'm curious how it ends up working for you. Cheers, -- Eric Gerlach, Network Administrator Federation of Students University of Waterloo p: (519) 888-4567 x36329 e: egerl...@feds.uwaterloo.ca -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
