• Copy this file to somewhere (e.g. ~/.git-prompt.sh).
• Add the following line to your .bashrc/.zshrc:

source ~/.git-prompt.sh

• Change your PS1 to call __git_ps1 as command-substitution:

Bash: 
  PS1='[\u@\h \W$(__git_ps1 " (%s)")]\$ '
  ZSH:  
  setopt PROMPT_SUBST ; PS1='[%n@%m %c$(__git_ps1 " (%s)")]\$ '

但请注意，只有git 1.9.3(2014年5月)or later允许您安全地显示该分支名称(！)

见commit 8976500 by @L_502_3@：

Both bash and zsh subject the value of PS1 to parameter expansion,command substitution,and arithmetic expansion.

Rather than include the raw,unescaped branch name in PS1 when running in two- or
three-argument mode,construct PS1 to reference a variable that holds the branch name.

Because the shells do not recursively expand,this avoids arbitrary code execution by specially-crafted branch names such as

'$(IFS=_;cmd=sudo_rm_-rf_/;$cmd)'.

什么愚蠢的心会命名这样的分支？ ;)(Beside a Mom as in xkcd)

still_dreaming_1 reports in the comments：

This seems to work great if you want a color prompt with xterm (in my .bashrc):

PS1='\[\e]0;\u@\h: \w\a\]\n${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\03‌​3[01;34m\]\w\[\033[00m\]$(__git_ps1)\$ '

Everything is a different color,including the branch.

在Linux Mint 17.3肉桂64位：

PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[01;34m\] \w\[\033[00m\]$(__git_ps1) \$ '