terminal 右边显示时间

在 ~/.oh-my-zsh/themes/agnoster.themes 增加

strlen () {
    FOO=$1
    local zero='%([BSUbfksu]|([FB]|){*})'
    LEN=${#${(S%%)FOO//$~zero/}}
    echo $LEN
}

# show right prompt with date ONLY when command is executed
preexec () {
    DATE=$( date +"[%H:%M:%S]" )
    local len_right=$( strlen "$DATE" )
    len_right=$(( $len_right+1 ))
    local right_start=$(($COLUMNS - $len_right))

    local len_cmd=$( strlen "[email protected]" )
    local len_prompt=$(strlen "$PROMPT" )
    local len_left=$(($len_cmd+$len_prompt))

    RDATE="