剪刀石头布【shell版】

尝试用shell编写的一个小游戏《剪刀石头布》，内容如下：

#!/bin/bash
#by song
#20150305
cai=("shitou" "jiandao" "bu")
read -p "enter your guess(shitou|jiandao|bu):" anwser
shitou=2
jiandao=1
bu=0
pc_cai=${cai[$((RANDOM%${#cai[*]}))]}
ren=$(eval echo \$$anwser)
pc=$(eval echo \$$pc_cai)
#布
if [[ "$anwser" = jiandao ]] || [[ "$anwser" = shitou ]] || [[ "$anwser" = bu ]];then
   if [[ "$ren" -eq "$bu" ]];then
      echo "ren guess bu"
      if [[ "$pc" -eq "$bu" ]];then
         echo "pc guess bu"
         echo -e "\e[33m人的布 战平 电脑的布\e[0m"
      elif [[ "$pc" -eq "$jiandao" ]];then
         echo "pc guess jiandao"
         echo -e "\e[31m人的布 败给 电脑的剪刀\e[0m"
      elif [[ "$pc" -eq "$shitou" ]];then
         echo "pc guess shitou"
         echo -e "\e[32m人的布 战胜 电脑的石头\e[0m"
       fi
   fi
   #剪刀
   if [[ "$ren" -eq "$jiandao" ]];then
      echo "ren guess jiandao"
      if [[ "$pc" -eq "$jiandao" ]];then
         echo "pc guess jiandao"
         echo -e "\e[33m人的剪刀 战平 电脑的剪刀\e[0m"
      elif [[ "$pc" -eq "$bu" ]];then
         echo "pc guess bu"
         echo -e "\e[32m人的剪刀 战胜 电脑的布\e[0m"
      elif [[ "$pc" -eq "$shitou" ]];then
         echo "pc guess shitou"
         echo -e "\e[31m人的剪刀 败给 电脑的石头\e[0m"
       fi
   fi
   #石头
   if [[ "$ren" -eq "$shitou" ]];then
      echo "ren guess shitou"
      if [[ "$pc" -eq "$shitou" ]];then
         echo "pc guess shitou"
         echo -e "\e[33m人的石头 战平 电脑的石头\e[0m"
      elif [[ "$pc" -eq "$bu" ]];then
         echo "pc guess bu"
         echo -e "\e[31m人的石头 败给 电脑的布\e[0m"
      elif [[ "$pc" -eq "$jiandao" ]];then
         echo "pc guess jiandao"
         echo -e "\e[32m人的石头 战胜 电脑的剪刀\e[0m"
       fi
   fi
else
  echo "please enter your guess(shitou|jiandao|bu)"
  exit 1
fi