2008/11/24 Carlos E. R. :

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On Monday, 2008-11-24 at 12:52 -0600, David C. Rankin wrote:

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I was trying to use chmod, but it says:

12:44 nirvana/srv/www/download> find . -type f -print0 | xargs -0 sudo chmod 0644 sudo: unable to execute /bin/chmod: Argument list too long

It's simple, just modify your command to : sudo find . -type f -exec chmod 0644 {} \; -print good luk! -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org

Brian K. White wrote:

----- Original Message ----- From: "Ricardo Gomez" To: Sent: Monday, November 24, 2008 3:47 PM Subject: Re: [opensuse] /bin/chmod: Argument list too long - how long is too long?

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2008/11/24 Carlos E. R. :

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On Monday, 2008-11-24 at 12:52 -0600, David C. Rankin wrote:

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I was trying to use chmod, but it says:

12:44 nirvana/srv/www/download> find . -type f -print0 | xargs -0 sudo chmod 0644 sudo: unable to execute /bin/chmod: Argument list too long

It's simple, just modify your command to :

sudo find . -type f -exec chmod 0644 {} \; -print

That's hardly any better. xargs is the correct tool for this job just as he originally tried. The very definition of xarg's job is to collect input into chunks that are as big as the shell can handle, but no bigger. It's whole point is to coalesce commands as much as the shell and the kernel will allow, because iterating through huge lists one file or one item at a time (as above, using find alone) is slow and inefficient a lot of times. It's true that some versions of find do, or can coalesce the arguments sort of like having xargs built-in, but that is the exception not the rule and shouldn't be relied on. His original command , of the form "find |xargs" was already the ideal.

The only thing I can think of is perhaps the sudo screws it up somehow. What the original command was really running was several big sudo commands, where really it's more expected to run several big chmod or other direct commands. (who wants to answer sudo password prompt 50 times?) sudo also just does a lot of funky stuff with the child environment in general and something like this result doesn't really surprise me.

I would try: su - find |xargs chmod

Also, there are options to reduce the buffer size xargs will assemble. find |xargs -s 32767

According to man xargs, the default size it will assemble is 131k, so 32k should be plenty safe and yet still make large enough command lines to chew through the job fast. Ovbviously you can play with the -s size and find where exactly it stops working and find the largest working value.

Excellent feedback. I'll give it a go and report back. This wouldn't be the first time sudo has bitten me. I guess as a rule, I should eliminate it from my scripts and go back to: ROOT_UID=0 E_NOTROOT=67 if [ "$UID" -ne "$ROOT_UID" ]; then echo -e "\nYou must be root to run this script.\nUser: $USER, UID: $UID can't! See below...\n" show_usage exit $E_NOTROOT fi In order to force either a true root execution or a sudo execution of the entire script instead of splitting commands with sudo as I originally did in the find | xargs situation. I'll let you know! -- David C. Rankin, J.D.,P.E. | openSoftware und SystemEntwicklung Rankin Law Firm, PLLC | Countdown for openSuSE 11.1 www.rankinlawfirm.com | http://counter.opensuse.org/11.1/small -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org

Hello, On Mon, 24 Nov 2008, Carlos E. R. wrote:

Yes, it depends on the length of the entire string, because all those file names are passed into a single string. At 15 chars per name, it makes more than 64KB, which I think is the limit. It is a limit of bash.

It's usually 128 KB under 32bit Linux. And it's a limit of the kernel. -dnh -- "It is very easy to be blinded to the essential uselessness of them by the sense of achievement you get from getting them to work at all." Hitchiker's Guide to the Galaxy on the Sirius Cybernetics Corporation. Does that seem familiar to anything on THIS planet at THIS time? -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org