find repos without local changes

gistfile1.txt

# find directories containing .git subdirs
find ~/ -type d -name '.git' -print0 | xargs -n 1 -0 dirname \
| xargs -I % -n 1 bash -c 'cd "%" && pwd 1>&2; (git status --porcelain| grep -q . && [[ ! -n "`git diff`" ]] ) || echo %'\
| xargs -I % bash -c '[[ -n "`cd %; git status --porcelain; git diff;`" ]] && echo %' \
| tee /dev/stderr | sort > purportedly-empty-repos.txt

#That makes sure you don't have any uncommitted changes.  But it still doesn't check to make sure you don't have unpushed commits.

iterating through each repo's branches to check against an upstream in bash? Maybe doable easily enough.