Using the Scala source repo to demonstrate - see Github

Show merged and unmerged branches

This command allows you to show all local branches merged / unmerged to current branch

➜  scala git:(2.12.x) git branch -a --merged
* 2.12.x
  remotes/origin/2.11.x
  remotes/origin/2.12.x
  remotes/origin/HEAD -> origin/2.12.x

➜  scala git:(2.12.x) git branch -a --no-merged
  remotes/origin/2.10.x
  remotes/origin/2.8.x
  remotes/origin/2.9.x
  remotes/origin/DarkDimius-patch-1
  remotes/origin/gh-pages
  remotes/origin/legacy/msil

This shows you all local branches merged into named branch:

➜  scala git:(2.12.x) git branch -a --merged origin/2.9.x
  remotes/origin/2.9.x

Better output

Put these 2 lines into ~/.gitconfig under the ‘[alias]’ section

unmerged = !git branch -r --no-merged | grep -v HEAD | xargs -L1 git --no-pager log --pretty=tformat:'%Cgreen%d%Creset | %h | %an | %Cblue%ar%Creset' -1 | column -t -s '|'
merged = !git branch -r --merged | grep -v HEAD | xargs -L1 git --no-pager log --pretty=tformat:'%Cgreen%d%Creset | %h | %an | %Cblue%ar%Creset' -1 | column -t -s '|'

Here is how my alias section looks like

This is the output of the commands

➜  scala git:(2.12.x) git unmerged
fatal: Unknown commit master

There are no local branches out of sync with master
➜  scala git:(2.12.x) git merged
 (origin/2.11.x)                               1fcfdd8    Lukas Rytz     4 days ago
 (HEAD, origin/HEAD, origin/2.12.x, 2.12.x)    0e4c39a    Vlad Ureche    2 days ago