如何才能得到准确的文件大小( MB )?我试过这个:
compressed_file_size = File.size("Compressed/#{project}.tar.bz2") / 1024000
puts "file size is #{compressed_file_size} MB"
但它砍掉了0.9,显示了2MB而不是2.9MB
发布于 2011-06-02 22:29:54
你正在做整数除法(去掉小数部分)。试着除以1024000.0,这样ruby就知道你想做浮点运算了。
发布于 2011-06-02 22:31:46
尝试:
compressed_file_size = File.size("Compressed/#{project}.tar.bz2").to_f / 1024000
发布于 2014-05-23 04:47:21
您可能会发现格式化函数很有用(pretty print file size),下面是我的示例,
def format_mb(size)
conv = [ 'b', 'kb', 'mb', 'gb', 'tb', 'pb', 'eb' ];
scale = 1024;
ndx=1
if( size < 2*(scale**ndx) ) then
return "#{(size)} #{conv[ndx-1]}"
end
size=size.to_f
[2,3,4,5,6,7].each do |ndx|
if( size < 2*(scale**ndx) ) then
return "#{'%.3f' % (size/(scale**(ndx-1)))} #{conv[ndx-1]}"
end
end
ndx=7
return "#{'%.3f' % (size/(scale**(ndx-1)))} #{conv[ndx-1]}"
end
测试一下,
tries = [ 1,2,3,500,1000,1024,3000,99999,999999,999999999,9999999999,999999999999,99999999999999,3333333333333333,555555555555555555555]
tries.each { |x|
print "size #{x} -> #{format_mb(x)}\n"
}
它产生了,
size 1 -> 1 b
size 2 -> 2 b
size 3 -> 3 b
size 500 -> 500 b
size 1000 -> 1000 b
size 1024 -> 1024 b
size 3000 -> 2.930 kb
size 99999 -> 97.655 kb
size 999999 -> 976.562 kb
size 999999999 -> 953.674 mb
size 9999999999 -> 9.313 gb
size 999999999999 -> 931.323 gb
size 99999999999999 -> 90.949 tb
size 3333333333333333 -> 2.961 pb
size 555555555555555555555 -> 481.868 eb
https://stackoverflow.com/questions/6215889
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