From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: "Lennart Borgman (gmail)" Newsgroups: gmane.emacs.devel Subject: Re: Why does not rgrep use "grep -r"? Date: Sat, 03 Nov 2007 00:56:17 +0100 Message-ID: <472BB921.20104@gmail.com> References: <472B99AB.3090705@gmail.com> <87ve8k8dyw.fsf@catnip.gol.com> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1194047809 22091 80.91.229.12 (2 Nov 2007 23:56:49 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 2 Nov 2007 23:56:49 +0000 (UTC) Cc: Emacs Devel , Miles Bader To: Andreas Schwab Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Nov 03 00:56:51 2007 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1Io6Nc-0001xV-8Z for ged-emacs-devel@m.gmane.org; Sat, 03 Nov 2007 00:56:48 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Io6NS-0003te-8M for ged-emacs-devel@m.gmane.org; Fri, 02 Nov 2007 19:56:38 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Io6NO-0003tZ-Vd for emacs-devel@gnu.org; Fri, 02 Nov 2007 19:56:35 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Io6NM-0003tN-LB for emacs-devel@gnu.org; Fri, 02 Nov 2007 19:56:33 -0400 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Io6NM-0003tK-EN for emacs-devel@gnu.org; Fri, 02 Nov 2007 19:56:32 -0400 Original-Received: from ch-smtp01.sth.basefarm.net ([80.76.149.212]) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1Io6NH-00014E-0h; Fri, 02 Nov 2007 19:56:27 -0400 Original-Received: from c83-254-148-228.bredband.comhem.se ([83.254.148.228]:63091 helo=[127.0.0.1]) by ch-smtp01.sth.basefarm.net with esmtp (Exim 4.68) (envelope-from ) id 1Io6NF-0006WJ-4L; Sat, 03 Nov 2007 00:56:25 +0100 User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.6) Gecko/20070728 Thunderbird/2.0.0.6 Mnenhy/0.7.5.666 In-Reply-To: X-Antivirus: avast! (VPS 071102-1, 2007-11-02), Outbound message X-Antivirus-Status: Clean X-Originating-IP: 83.254.148.228 X-Scan-Result: No virus found in message 1Io6NF-0006WJ-4L. X-Scan-Signature: ch-smtp01.sth.basefarm.net 1Io6NF-0006WJ-4L 51bfe9e935bc35d1778ba5c0bdfa867c X-detected-kernel: by monty-python.gnu.org: Linux 2.6? (barebone, rare!) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:82389 Archived-At: Andreas Schwab wrote: > Miles Bader writes: > >> I don't know the reason of the rgrep authors (though I suspect it was >> portability concerns), but I have noticed something odd about "grep -r": >> -- sometimes it seems _much_ slower than "find ... -type f | xargs grep" >> on very large trees (I think I noticed with trees in NFS, where speed is >> a perennial issue). > > Probably because find has been optimized for, umm, finding files. There > are quite a few things you can do to speed up directory traversal. I guess it also depends on what kind of OS you are using, is process creation cheap or not.