Getting size with du of files only

I usually use the -exec utility. Like this:

find . -type f -exec du -a {} +

I tried it both on bash and ksh with GNU find. I never tried AIX, but I'm sure your version of find has some -exec syntax.

The following snippet sorts the list, largest first:

find . -type f -exec du -a {} + | sort -n -r | less

If you have GNU utilities, try

find . -type f -print0 | du --files0-from=-

I generally use:

find . -type f -print0 | xargs -r0 du -a

Xargs usually calls the command, even if there are no arguments passed; xargs du </dev/null will still be called, xargs -r du </dev/null will not call du. The -0 argument looks for null-terminated strings instead of newline terminated.

Then I usually add | awk '{sum+=$1} END {print sum}' on the end to get the total.