Print commit message of a given commit in git

Not plumbing, but I have these in my .gitconfig:

lsum = log -n 1 --pretty=format:'%s'
lmsg = log -n 1 --pretty=format:'%s%n%n%b'

That's "last summary" and "last message". You can provide a commit to get the summary or message of that commit. (I'm using 1.7.0.5 so don't have %B.)

git show is more a plumbing command than git log, and has the same formatting options:

git show -s --format=%B SHA1

It's not "plumbing", but it'll do exactly what you want:

$ git log --format=%B -n 1 <commit>

If you absolutely need a "plumbing" command (not sure why that's a requirement), you can use rev-list:

$ git rev-list --format=%B --max-count=1 <commit>

Although rev-list will also print out the commit sha (on the first line) in addition to the commit message.

This will give you a very compact list of all messages for any specified time.

git log --since=1/11/2011 --until=28/11/2011 --no-merges --format=%B > CHANGELOG.TXT