Date: Fri, 30 Apr 2004 23:28:09 +1000 (EST) From: Bruce Evans <bde@zeta.org.au> To: Kris Kennaway <kris@obsecurity.org> Cc: Julian Elischer <julian@elischer.org> Subject: Re: code cleanup Message-ID: <20040430231553.X15963@gamplex.bde.org> In-Reply-To: <20040429215236.GA42902@xor.obsecurity.org> References: <200404291855.i3TItUTr048530@green.homeunix.org> <20040429215236.GA42902@xor.obsecurity.org>
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On Thu, 29 Apr 2004, Kris Kennaway wrote:
> On Thu, Apr 29, 2004 at 04:56:02PM -0400, John Baldwin wrote:
> > On Thursday 29 April 2004 02:55 pm, Brian Fundakowski Feldman wrote:
> > > For what it's worth, I don't think it is good to hide things as much as
> > > FOREACH_PROC_IN_SYSTEM() -- this specific instance -- does, but grep is not
> > > a good tool for a tree as large as FreeBSD's. Try using cscope instead.
> >
> > I've used glimpse in the past but it is buggy. Actually, grep -r on ssc/sys
> > doesn't take that long, esp. if you do it multiple times as most of the tree
> > is still in cache for subsequent grep's (at least on my laptop). I also tend
> > to have lots (around 7 or so) trees that have work going on in them at any
> > one time.
>
> The problem with grep -r in src/sys is that it chokes on the symlinks
> created by module builds and pollutes the output with hundreds of
> lines of errors unless you remember to first remove the module build
> files.
Use find(1) to not follow symlinks. E.g.:
%%%
Script started on Fri Apr 30 23:15:17 2004
ttyp0:bde@besplex:/tmp> cd /sys
ttyp0:bde@besplex:/sys> time find . -type f | time xargs grep fooo
0.42 real 0.01 user 0.06 sys
0.49 real 0.11 user 0.29 sys
ttyp0:bde@besplex:/sys> exit
Script done on Fri Apr 30 23:15:33 2004
%%%
This was fast because /sys was already in the disk cache. It would have
taken 15 seconds with a cold cache.
I also have:
lrwxrwxrwx 1 bde wheel 28 Mar 6 06:57 /sys/i386/compile@ -> /usr/obj/usr/src/sys/compile
(see Makefile.i386 rev.1.28)
so I don't have any object files under /sys to slow down the search,
except grep -r would follow this symlink too.
Perhaps it is a bug for grep -r to follow symlinks by default, especially
since there is no way to change the default and whether symlinks are
followed is not mentioned in the man page. diff -r has the same problem.
Bruce
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