git-purge is git sub command to delete merged branches.
THIS APPLICATION IS VERY EXPERIMENTAL. THERE ARE NO GUARANTEE FOR RESULT OF IT. YOU SHOULDN'T USE IT IF YOU CANNOT UNDERSTAND ITS BEHAVIOR.
go get github.com/handlename/git-purge
To delete all merged branches, run git purge without any options.
$ git purge
With --dryrun option, list branches and do nothing more.
$ git purge --dryrun
If you want to delete remote branches too, try --remote option.
$ git purge --remote
--ignore "<regexp>" ignores branches matches <regexp>.
$ git purge --ignore "keep/.*"
MIT