Exclude all permission denied messages from "du"

du -cBM --max-depth=1 2>/dev/null | sort -n 

or better in bash (just filter out this particular error, not all like last snippet)

du -cBM --max-depth=1 2> >(grep -v 'Permission denied') | sort -n 

2> /dev/nul hides only error messages.

the command du always try run over directory. Imagine that you have thousands of dirs?

du needs eval, if you have persmission run if not, follow with the next dir...

I'd use something concise that excludes only the lines you don't want to see. Redirect stderr to stdout, and grep to exclude all "denied"s:

du -cBM --max-depth=1 2>&1 | grep -v 'denied' | sort -n