To get a prompt which indicates Git-branch in Zsh

I run the following codes separately as my prompt unsuccessfully in .zshrc. This suggests me that apparently I do not have a program called __git_ps1. It is not in MacPorts.

#1

PROMPT="$(__git_ps1 " \[\033[1;32m\] (%s)\[\033[0m\]")\$"$

#2

PROMPT="$(__git_ps1 " (%s)")\$"$

#3

# Get the name of the branch we are on
git_prompt_info() {
  branch_prompt=$(__git_ps1)
  if [ -n "$branch_prompt" ]; then
    status_icon=$(git_status)
    echo $branch_prompt $status_icon
  fi
}

# Show character if changes are pending
git_status() {
  if current_git_status=$(git status | grep 'added to commit' 2> /dev/null); then
    echo "☠"
  fi
}
autoload -U colors
colors
setopt prompt_subst
PROMPT='
%~%{$fg_bold[black]%}$(git_prompt_info)
→ %{$reset_color%}'

How can you get a prompt which shows the name of a Git-branch?

Solution

__git_ps1 is from git-completion.bash. In zsh you probably have to provide your own function to determine the current directories git branch. There are quite a few blog posts about a git prompt for zsh.

You just need:

a function to provide the branch name
enable prompt (command) substitution
add the function to your prompt

For example

git_prompt() {
 ref=$(git symbolic-ref HEAD | cut -d'/' -f3)
 echo $ref
}
setopt prompt_subst
PS1=$(git_prompt)%#
autoload -U promptinit
promptinit

Update: use the zsh vcs_info module instead of git_prompt()

setopt prompt_subst
autoload -Uz vcs_info
zstyle ':vcs_info:*' actionformats \
    '%F{5}(%f%s%F{5})%F{3}-%F{5}[%F{2}%b%F{3}|%F{1}%a%F{5}]%f '
zstyle ':vcs_info:*' formats       \
    '%F{5}(%f%s%F{5})%F{3}-%F{5}[%F{2}%b%F{5}]%f '
zstyle ':vcs_info:(sv[nk]|bzr):*' branchformat '%b%F{1}:%F{3}%r'

zstyle ':vcs_info:*' enable git cvs svn

# or use pre_cmd, see man zshcontrib
vcs_info_wrapper() {
  vcs_info
  if [ -n "$vcs_info_msg_0_" ]; then
    echo "%{$fg[grey]%}${vcs_info_msg_0_}%{$reset_color%}$del"
  fi
}
RPROMPT=$'$(vcs_info_wrapper)'