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Subject: RE:  Re: find . -regex '.*js' -type f -exec md5sum '{}' \\; really slow!
Date: Mon, 24 Nov 2008 17:53:38 -0500
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From: "Buchbinder, Barry (NIH/NIAID) [E]" <BBuchbinder AT niaid DOT nih DOT gov>
To: <cygwin AT cygwin DOT com>, "Matthew Woehlke" <mw_triad AT users DOT sourceforge DOT net>
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The following may technically be off-topic.  If so, I apologize.

Matthew Woehlke wrote on Monday, November 24, 2008 12:46 PM:
> Bartolomeo Nicolotti wrote:
>> but the command
>> 
>> find . -type f | xargs md5sum
>> 
>> has problems with blanks in the name of the files:
>> [snip examples]
> 
> find . -type f -print0 | xargs -0 md5sum

I've found that find is significantly slower than native tools.  (The following was run several times to fill any cached file system data.)

    local hard disk (C:):

	> time "$(cygpath -u "${COMSPEC}")" /c dir /s /b /a:-d | wc
	  16085   16308  690388

	real    0m0.343s
	user    0m0.122s
	sys     0m0.170s

    networked drive:

	> time "$(cygpath -u "${COMSPEC}")" /c dir /s /b /a:-d | wc
	   1183    3093   66761

	real    0m3.078s
	user    0m0.075s
	sys     0m0.108s

	> time find . -type f | wc      ")" /c d
	   1183    3093   53748

	real    1m0.813s
	user    0m0.216s
	sys     0m8.046s

Therefore, you might consider using something like this if there are no symbolic links* and it doesn't offend your sensibilities.  (* and other "oddities".  I'm not sure how symbolic links work with find . -type f, so this might not be a problem.)

"$(cygpath -u "${COMSPEC}")" /c dir /s /b /a:-d | \
	tr -s '\r\n' '\n' | \
	cygpath -u -f - | \
	tr '\n' '\0' | \
	xargs -r0 md5sum

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