duc xml: Ability to specify min actual size vs. apparent size

[ech3]

Currently with the duc xml -s switch, this is calculated based on the apparent size and not the actual size. I have a variety of tools which create sparse files and they are triggering my script that uses duc, but when I report the size via du, the size is much smaller because I am not using the --apparent switch with du. Steps in UNIX to reproduce the problem:

mkdir temp
cd temp
truncate -s 512M file.img
duc index -d file.duc .
duc xml -s 1024000 -d file.duc

Here is the output:
<?xml version="1.0" encoding="UTF-8"?>
<duc root="." size_apparent="537137664" size_actual="560128">
<ent name="file.img" size_apparent="536870912" size_actual="1536" />
</duc>

In my case I only care about actual size use, not apparent size usage. Having either an option to specify that I only care about actual size, or a modifier to change how the -s is interpreted would be appreciated. Again, thanks for all your hard work on this program.