oh-my-zsh/lib/git.zsh

# get the name of the branch we are on
function git_prompt_info() {
  ref=$(git symbolic-ref HEAD 2> /dev/null) || return
  echo "$ZSH_THEME_GIT_PROMPT_PREFIX${ref#refs/heads/}$(parse_git_dirty)$ZSH_THEME_GIT_PROMPT_SUFFIX"
}

# get dirty status of the current working tree
parse_git_dirty () {
  if [[ -n $(git status -s 2> /dev/null) ]]; then
    echo "$ZSH_THEME_GIT_PROMPT_DIRTY"
  else
    echo "$ZSH_THEME_GIT_PROMPT_CLEAN"
  fi
}

# get the difference between the local and remote branches
git_remote_status() {
    remote=${$(git rev-parse --verify ${hook_com[branch]}@{upstream} --symbolic-full-name 2>/dev/null)/refs\/remotes\/}
    if [[ -n ${remote} ]] ; then
        ahead=$(git rev-list ${hook_com[branch]}@{upstream}..HEAD 2>/dev/null | wc -l)
        behind=$(git rev-list HEAD..${hook_com[branch]}@{upstream} 2>/dev/null | wc -l)

        if [ $ahead -eq 0 ] && [ $behind -gt 0 ]
        then
            echo "$ZSH_THEME_GIT_PROMPT_BEHIND_REMOTE"
        elif [ $ahead -gt 0 ] && [ $behind -eq 0 ]
        then
            echo "$ZSH_THEME_GIT_PROMPT_AHEAD_REMOTE"
        elif [ $ahead -gt 0 ] && [ $behind -gt 0 ]
        then
            echo "$ZSH_THEME_GIT_PROMPT_DIVERGED_REMOTE"
        fi
    fi
}

# get the status of the working tree
git_prompt_status() {
  INDEX=$(git status --porcelain 2> /dev/null)
  STATUS=""
  if $(echo "$INDEX" | grep '^?? ' &> /dev/null); then
    STATUS="$ZSH_THEME_GIT_PROMPT_UNTRACKED$STATUS"
  fi
  if $(echo "$INDEX" | grep '^A  ' &> /dev/null); then
    STATUS="$ZSH_THEME_GIT_PROMPT_ADDED$STATUS"
  elif $(echo "$INDEX" | grep '^M  ' &> /dev/null); then
    STATUS="$ZSH_THEME_GIT_PROMPT_ADDED$STATUS"
  fi
  if $(echo "$INDEX" | grep '^ M ' &> /dev/null); then
    STATUS="$ZSH_THEME_GIT_PROMPT_MODIFIED$STATUS"
  elif $(echo "$INDEX" | grep '^AM ' &> /dev/null); then
    STATUS="$ZSH_THEME_GIT_PROMPT_MODIFIED$STATUS"
  elif $(echo "$INDEX" | grep '^ T ' &> /dev/null); then
    STATUS="$ZSH_THEME_GIT_PROMPT_MODIFIED$STATUS"
  fi
  if $(echo "$INDEX" | grep '^R  ' &> /dev/null); then
    STATUS="$ZSH_THEME_GIT_PROMPT_RENAMED$STATUS"
  fi
  if $(echo "$INDEX" | grep '^ D ' &> /dev/null); then
    STATUS="$ZSH_THEME_GIT_PROMPT_DELETED$STATUS"
  fi
  if $(echo "$INDEX" | grep '^UU ' &> /dev/null); then
    STATUS="$ZSH_THEME_GIT_PROMPT_UNMERGED$STATUS"
  fi
  echo $STATUS
}