shell 提示符个性化设置

提示符具体含义可参考： http://billie66.github.io/TLCL/book/zh/chap14.html

Ubuntu16.04个人配置如下，供以后查阅

function git_branch {
   branch="`git branch 2>/dev/null | grep "^\*" | sed -e "s/^\*\ //"`"
   if [ "${branch}" != "" ];then
      if [ "${branch}" = "(no branch)" ];then
         branch="(`git rev-parse --short HEAD`...)"
      fi
      echo " ($branch)"
   fi
}
export PS1='\[\033[4;45m\]\u\[\033[00m\]@\h \[\033[01;36m\]\W\[\033[01;32m\]$(git_branch)\[\033[00m\]\$ '