You have a file with a funny name, probably starting with a -. Remember that globs (like *) are expanded by your shell, not the command being run. As an example, say you have:
$ ls -1
foo
-q
Simple enough directory, with two files in it. (The -1 option to coreutils ls makes its output single-column.)
When you run du -sh *, the shell notices that the second argument contains a special character (*) and isn't quoted, so it does glob expansion. It expands it to everything that matches, in this case foo and -q. The effect is exactly as if you'd run:
$ du -sh foo -q
du: invalid option -- 'q'
Try 'du --help' for more information.
The error above is clear: GNU utilities allow options mixed with file names for convenience; du is taking the file name -q as an option. And there isn't a -q option. (This is actually the best you can expect; worse would be if there were a -q option, and it did something unwanted.)
Stépahane's suggestion is to change your glob to ./*, which would result in du -sh ./foo ./-q—which of course is taken as a file name, because it no longer begins with -. The other option he suggests is to use --, which tells GNU utilities that there are no more options—only file/directory names.
Really you should always use either … ./* or … -- * instead of *, but we're all lazy…. Just be careful, especially if you don't trust all the file names.
du -sh ./*ordu -sh -- *– Stéphane Chazelas Apr 07 '15 at 20:07