A command line utility to test the status of files in iCloud drive directory
You can use brctl status.

It outputs alot, but you can grep pretty easily, for example brctl status |grep needs-sync-up |cut -d'"' -f2 will show you all files waiting for being uploaded (without their path), or use brctl status |grep 'somefile.ext' for checking the status of somefile.ext.

See brctl --help for more.