On Fri, 31 May 2013 15:01:59 +0100 Chris Rees <utis...@gmail.com> wrote:
> Hi all, > > I think I've discovered a strange behaviour of sed perhaps triggered > by the length of a regex passed to it. I noticed that a certain > expression I passed took a very long time, and suspected the usual > backtracking loop, so I started trimming it... and discovered this: > > [crees@pegasus]~% time sed -ne "s,^BitchX-[0-9][^|]*[\|]/usr/por,," > /var/db/pkg/INDEX-9 > 4.699u 0.007s 0:04.70 99.7% 40+2733k 0+0io 0pf+0w > [crees@pegasus]~% time sed -ne "s,^BitchX-[0-9][^|]*[\|]/usr/po,," > /var/db/pkg/INDEX-9 > 0.042u 0.000s 0:00.04 100.0% 48+3216k 0+0io 0pf+0w > > I've looked at the code, and can't from a brief glance figure out why > a slightly longer regex makes such a difference-- does it start to > split it? Perhaps second one uses memory cache data? Run both twice and show us the second times. > Chris > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org" --- --- Eduardo Morras <emorr...@yahoo.es> _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
