display stash number if stash >= 1

zshrc

## show git branch at right prompt
autoload -Uz vcs_info
zstyle ':vcs_info:*' formats '[%b]'
zstyle ':vcs_info:*' actionformats '(%s)-[%b|%a]'
precmd () {
    psvar=()
    LANG=en_US.UTF-8 vcs_info
    [[ -n "$vcs_info_msg_0_" ]] && psvar[1]="$vcs_info_msg_0_"

    topdir=`git rev-parse --show-toplevel 2>/dev/null`
    if [ $? -eq 0 ]
    then
        stashes=$(git stash list 2>/dev/null | wc -l)
        if [ ${stashes} -eq 0 ]
        then
            psvar[2]=""
        else
            psvar[2]=" @${stashes// /}"
        fi
    fi
}
_DIRPART=%B%{$fg[cyan]%}'[%(5~,%-2~/.../%2~,%~)]'%{$reset_color%}%b
RPROMPT=%B"%1(v|%F{magenta}%1v%f%F{yellow}%2v%f|)"%b${_DIRPART}