Re: [PLUG] Copying files to multiple volumes

[Rich Kulawiec via plug <plug@lists.phillylinux.org>]

On Wed, Oct 28, 2020 at 05:11:19PM -0400, Walt Mankowski via plug wrote:
> My fallback is to run `du -b --max-depth=1`, load the output into a
> spreadsheet, and hope that I can find point in the middle that leaves
> half on each side. But I'm hoping there might be something to automate
> it.

It's probably not worth coming up with an automated solution for a one-time
application, but here's something I've used to do what you suggest -- finding
a point in the middle that roughly splits the total.

	du -sm * | awk -f /some/path/to/add.awk

where add.awk is: 

	BEGIN { tot = 0 }
	/^.*/			{tot = tot + $1; print $0, "	", tot}
	END {  print tot}

(Note that there are tab characters in there.)

You might wonder this is awk and not Perl...well, that's because it
was written well before Perl existed.  That little three-line awk
script has a lot of miles on it.

Anyway, the -s flag to du tells it to summarize by directory, the -m
flag says to use megabytes as the units.   (Salt to taste if you want
kbytes or gbytes.)  The output of the awk script is its input plus
a running total to the right, e.g. when the incantation above is run
in a directory with the last five OpenBSD distributions, it yields:

	1322	openbsd-6.4 	 1322
	1451	openbsd-6.5 	 2773
	1525	openbsd-6.6 	 4298
	1540	openbsd-6.7 	 5838
	1658	openbsd-6.8 	 7496
	7496

Sooooo, look at the number at the bottom, divide by 2, scroll back up
to find out where it shows up on the right.  In this case, 3748 isn't
there but 4298 is probably close enough.  If the list is too long
to scroll through, redirect the output to a file and use a text editor.

---rsk
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