I exploit the same trick to have a script automatically set what it thinks a commit message should be, but still pass it for human review/edit before actually committing and pushing. Come to think of it, you could easily use this to set a default message base and do things like always prefix the directory; I like my commits to be something like "modules/foo: added bar", so I could just alias gc='git commit -m "${PWD##*/}" -e' (well, something like that, but more sophisticated).