Terminal git 显示当前分支

find_git_branch () {
local dir=. head
until [ "$dir" -ef / ]; do
if [ -f "$dir/.git/HEAD" ]; then
head=$(< "$dir/.git/HEAD")
if [[ $head = ref:\ refs/heads/* ]]; then
git_branch=" | ${head#*/*/}"
elif [[ $head != '' ]]; then
git_branch=" | (detached)"
else
git_branch=" | (unknow)"
fi
return
fi
dir="../$dir"
done
git_branch=''
}

PROMPT_COMMAND="find_git_branch; $PROMPT_COMMAND"
PS1="\u@\h:\w\$git_branch\$ "