From: Curious Person <antispam@...>
Date: 2003-01-29T01:41:41+09:00
Subject: FileTest.size? vs du -b

I've noticed something curious.  I was throwing together a small script 
when I noticed that FileTest.size? give a defferent byte size than du -b on 
the same file.  Here's the source:

    require 'find'

    def tree_size( file )
        result = 0
        
        Find.find (file) do |x|
            r = FileTest.size?( x )
            puts "#{r}\t#{x}"
            result += r
        end
        
        result
    end

    puts File.size( ARGV[0] )
    puts tree_size( ARGV[0] )


And here's the output I get:

$ ruby ~/text.rb test_dir/

    4096
    4096    test_dir/
    5805035 test_dir//file 4 of 4.foo
    7388160 test_dir//file 3 of 4.foo
    7444001 test_dir//file 2 of 4.foo
    7448001 test_dir//file 1 of 4.foo
    28089293

Out of curiousity, I compared it to what du would return:

$ du -sbc test_dir:

    7462912 test_dir/file 1 of 4.foo
    7458816 test_dir/file 2 of 4.foo
    7401472 test_dir/file 3 of 4.foo
    5820416 test_dir/file 4 of 4.foo
    28143616        total

Er... something doesn't add up.  BTW, when I verify the filesizes with ls -
al, it matches what FileTest.size returns.  Does anyone know what's going 
on here?  Is du inaccurate?

Have a Nice Day,
-Curious.