From owner-freebsd-fs@FreeBSD.ORG  Fri Mar  8 20:05:50 2013
Return-Path: <owner-freebsd-fs@FreeBSD.ORG>
Delivered-To: freebsd-fs@freebsd.org
Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115])
 by hub.freebsd.org (Postfix) with ESMTP id CB479615;
 Fri,  8 Mar 2013 20:05:50 +0000 (UTC)
 (envelope-from wblock@wonkity.com)
Received: from wonkity.com (wonkity.com [67.158.26.137])
 by mx1.freebsd.org (Postfix) with ESMTP id 803CF7DC;
 Fri,  8 Mar 2013 20:05:50 +0000 (UTC)
Received: from wonkity.com (localhost [127.0.0.1])
 by wonkity.com (8.14.6/8.14.6) with ESMTP id r28K5fAF089779;
 Fri, 8 Mar 2013 13:05:41 -0700 (MST)
 (envelope-from wblock@wonkity.com)
Received: from localhost (wblock@localhost)
 by wonkity.com (8.14.6/8.14.6/Submit) with ESMTP id r28K5fvX089776;
 Fri, 8 Mar 2013 13:05:41 -0700 (MST)
 (envelope-from wblock@wonkity.com)
Date: Fri, 8 Mar 2013 13:05:41 -0700 (MST)
From: Warren Block <wblock@wonkity.com>
To: Brooks Davis <brooks@freebsd.org>
Subject: Re: Argument list too long
In-Reply-To: <20130308190917.GA34838@lor.one-eyed-alien.net>
Message-ID: <alpine.BSF.2.00.1303081239450.89649@wonkity.com>
References: <82112.1362671436.13776555968178880512@ffe17.ukr.net>
 <20130307161546.GV47829@e-new.0x20.net>
 <20130308190917.GA34838@lor.one-eyed-alien.net>
User-Agent: Alpine 2.00 (BSF 1167 2008-08-23)
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7
 (wonkity.com [127.0.0.1]); Fri, 08 Mar 2013 13:05:41 -0700 (MST)
Cc: freebsd-fs@freebsd.org
X-BeenThere: freebsd-fs@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: Filesystems <freebsd-fs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-fs>,
 <mailto:freebsd-fs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-fs>
List-Post: <mailto:freebsd-fs@freebsd.org>
List-Help: <mailto:freebsd-fs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
 <mailto:freebsd-fs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 08 Mar 2013 20:05:50 -0000

On Fri, 8 Mar 2013, Brooks Davis wrote:

> On Thu, Mar 07, 2013 at 05:15:46PM +0100, Lars Engels wrote:
>> On Thu, Mar 07, 2013 at 05:50:36PM +0200, Vladislav Prodan wrote:
>>> Why 12K small files from one directory to cause problems?
>>>
>>> # ll | wc -l
>>>    11467
>>>
>>> # grep X-PHP-Script * | more
>>> /sbin/grep: Argument list too long.
>>>
>>> # egrep X-PHP-Script *.ua | more
>>> /usr/sbin/egrep: Argument list too long.
>>>
>>> # cat *.ua | grep X-PHP-Script | more
>>> /sbin/cat: Argument list too long.
>>>
>>>
>>>
>>
>> Your shell can't process that many arguments. Use this:
>>
>> grep -R "X-PHP-Script" .
>>
>> or if you don't want to descent into subdirectories:
>>
>> find . -type -f -name '*.ua' -maxdepth 1 -exec grep "X-PHP-Script" {} \+

There is a typo, should be "-type f".

> This won't include file names and is gratuitously inefficient starting one
> grep per file.

But the final \+ means "{} is replaced with as many pathnames as 
possible for each invocation of utility.  This behaviour is similar to 
that of xargs(1)."

> The command you're looking for is:
>
> find . -type -f -name '*.ua' -maxdepth 1 -print0 | xargs -0 grep -H "X-PHP-Script"
>
> The find -print0 | xargs -0 allows filenames to contain spaces.  The
> grep -H is mostly theoretical in that the last grep invocation by xargs
> couple only include one file and thus wouldn't include the filename.

For fun, after running each of these several times to preload cache:

find /usr/ports -type f -print0 | xargs -0 grep -H "X-PHP-Script"
40.98 seconds (average)

find /usr/ports -type f -exec grep -H "X-PHP-Script" {} \+
42.27 seconds (average)

So they aren't too different in performance.