git-prune-merged-branches

#!/bin/sh
#/ Usage: git prune-merged-branches [-fu] [-r <remote>] <merge-branch>
#/ Delete all branches that are fully merged into <merge-branch>.
#/
#/ Options:
#/   -f            Really delete the branches. Without this, branches are shown but
#/                 not actually deleted.
#/   -r <remote>   Name of remote to operate on. Operate locally when not specified.
#/   -u            Fetch <remote> before determining merged branch status.
#/
#/ Examples:
#/   List local branches already merged into master for inspection:
#/     git prune-merged-branches master
#/
#/   Delete local branches already merged into master:
#/     git prune-merged-branches -f master
#/
#/   List branches in origin remote already merged into origin/master:
#/     git prune-merged-branches -u -r origin master
#/
#/   Delete branches in origin remote already merged into origin/master:
#/     git prune-merged-branches -f -r origin master
set -e

# show usage message and exit
usage () {
    status=${1:-0}
    grep '^#/' <"$0"| cut -c4-
    exit $status
}
[ $# -eq 0 -o "$1" = "--help" ] && usage

# parse arguments
force=false
update=false
remote=
while getopts hfur: name
do
    case $name in
    f)    force=true;;
    r)    remote="$OPTARG";;
    u)    update=true;;
    ?)    usage 2;;
    esac
done
shift $(($OPTIND - 1))

# remaining arg must be a branch name
branch="$1"
[ -n "$branch" ] || usage 2

# determine branches to delete based on local or remote mode
if [ -n "$remote" ]
then
    $update && git fetch "$remote" --prune
    mode=Remote
    branch_name="$remote/$branch"
    branches=$(
        git branch --no-color -a --merged "$remote/$branch" |
        grep "^..remotes/$remote/" |
        grep -v "^..remotes/$remote/$branch$" |
        grep -v " -> " |
        sed 's|^\(..\)remotes/'$remote'/|\1|'
    )
else
    mode=Local
    branch_name="$branch"
    branches=$(
        git branch --no-color --merged "$branch" |
        grep -v "^..$branch$" |
        grep -v " -> "
    )
fi

# bail out with no branches
[ -z "$branches" ] && {
    echo "no merged branches detected" 1>&2
    exit 0
}

# with no -f option, just show branches that would be deleted
if ! $force
then echo "$mode branches fully merged into $branch_name:" 1>&2
     echo "$branches"
     echo "Use \`$(basename "$0") -f' if you're sure." 1>&2
     exit
fi

# actually delete the branches via push if remote or via branch -D if local
if [ -n "$remote" ]
then git push origin $(echo "$branches" | sed 's/^../:/')
else git branch -D $(echo "$branches" | cut -c2-)
fi