这是我见过最牛逼的Shell，619行代码！

#!/bin/bash
# Tetris Game
#APP declaration
APP_NAME="${0##*[/]}"
APP_VERSION="1.0"

#颜色定义
cRed=1
cGreen=2
cYellow=3
cBlue=4
cFuchsia=5
cCyan=6
cWhite=7
colorTable=($cRed $cGreen $cYellow $cBlue $cFuchsia $cCyan $cWhite)
#位置和大小
iLeft=3
iTop=2
((iTrayLeft = iLeft + 2))
((iTrayTop = iTop + 1))
((iTrayWidth = 10))
((iTrayHeight = 15))
#颜色设置
cBorder=$cGreen
cScore=$cFuchsia
cScoreValue=$cCyan
#控制信号
#改游戏使用两个进程，一个用于接收输入，一个用于游戏流程和显示界面;
#当前者接收到上下左右等按键时，通过向后者发送signal的方式通知后者。
sigRotate=25
sigLeft=26
sigRight=27
sigDown=28
sigAllDown=29
sigExit=30
#七中不同的方块的定义
#通过旋转，每种方块的显示的样式可能有几种
box0=(0 0 0 1 1 0 1 1)
box1=(0 2 1 2 2 2 3 2 1 0 1 1 1 2 1 3)
box2=(0 0 0 1 1 1 1 2 0 1 1 0 1 1 2 0)
box3=(0 1 0 2 1 0 1 1 0 0 1 0 1 1 2 1)
box4=(0 1 0 2 1 1 2 1 1 0 1 1 1 2 2 2 0 1 1 1 2 0 2 1 0 0 1 0 1 1 1 2)
box5=(0 1 1 1 2 1 2 2 1 0 1 1 1 2 2 0 0 0 0 1 1 1 2 1 0 2 1 0 1 1 1 2)
box6=(0 1 1 1 1 2 2 1 1 0 1 1 1 2 2 1 0 1 1 0 1 1 2 1 0 1 1 0 1 1 1 2)
#所有其中方块的定义都放到box变量中
box=(${box0[@]} ${box1[@]} ${box2[@]} ${box3[@]} ${box4[@]} ${box5[@]} ${box6[@]})
#各种方块旋转后可能的样式数目
countBox=(1 2 2 2 4 4 4)
#各种方块再box数组中的偏移
offsetBox=(0 1 3 5 7 11 15)
#每提高一个速度级需要积累的分数
iScoreEachLevel=50 #be greater than 7
#运行时数据
sig=0        #接收到的signal
iScore=0     #总分
iLevel=0     #速度级
boxNew=()    #新下落的方块的位置定义
cBoxNew=0    #新下落的方块的颜色
iBoxNewType=0     #新下落的方块的种类
iBoxNewRotate=0   #新下落的方块的旋转角度
boxCur=()         #当前方块的位置定义
cBoxCur=0         #当前方块的颜色
iBoxCurType=0     #当前方块的种类
iBoxCurRotate=0   #当前方块的旋转角度
boxCurX=-1        #当前方块的x坐标位置
boxCurY=-1        #当前方块的y坐标位置
iMap=()           #背景方块图表
#初始化所有背景方块为-1, 表示没有方块
for ((i = 0; i < iTrayHeight * iTrayWidth; i++)); do iMap[$i]=-1; done

#接收输入的进程的主函数
function RunAsKeyReceiver()
{
 local pidDisplayer key aKey sig cESC sTTY
 pidDisplayer=$1
 aKey=(0 0 0)
 cESC=`echo -ne ""`
 cSpace=`echo -ne " "`
 #保存终端属性。在read -s读取终端键时，终端的属性会被暂时改变。
 #如果在read -s时程序被不幸杀掉，可能会导致终端混乱，
 #需要在程序退出时恢复终端属性。
 sTTY=`stty -g`
 #捕捉退出信号
 trap "MyExit;" INT TERM
 trap "MyExitNoSub;" $sigExit
 #隐藏光标
 echo -ne "[?25l"

 while :
 do
 #读取输入。注-s不回显，-n读到一个字符立即返回
 read -s -n 1 key
 aKey[0]=${aKey[1]}
 aKey[1]=${aKey[2]}
 aKey[2]=$key
 sig=0
 #判断输入了何种键
 if [[ $key == $cESC && ${aKey[1]} == $cESC ]]
 then
 #ESC键
 MyExit
 elif [[ ${aKey[0]} == $cESC && ${aKey[1]} == "[" ]]
 then
 if [[ $key == "A" ]]; then sig=$sigRotate       #<向上键>
 elif [[ $key == "B" ]]; then sig=$sigDown       #<向下键>
 elif [[ $key == "D" ]]; then sig=$sigLeft       #<向左键>
 elif [[ $key == "C" ]]; then sig=$sigRight      #<向右键>
 fi
 elif [[ $key == "W" || $key == "w" ]]; then sig=$sigRotate #W, w
 elif [[ $key == "S" || $key == "s" ]]; then sig=$sigDown #S, s
 elif [[ $key == "A" || $key == "a" ]]; then sig=$sigLeft #A, a
 elif [[ $key == "D" || $key == "d" ]]; then sig=$sigRight #D, d
 elif [[ "[$key]" == "[]" ]]; then sig=$sigAllDown    #空格键
 elif [[ $key == "Q" || $key == "q" ]] #Q, q
 then
 MyExit
 fi
 if [[ $sig != 0 ]]
 then
 #向另一进程发送消息
 kill -$sig $pidDisplayer
 fi
 done
}
#退出前的恢复
function MyExitNoSub()
{
 local y
 #恢复终端属性
 stty $sTTY
 ((y = iTop + iTrayHeight + 4))
 #显示光标
 echo -e "[?25h[${y};0H"
 exit
}

function MyExit()
{
 #通知显示进程需要退出
 kill -$sigExit $pidDisplayer
 MyExitNoSub
}

#处理显示和游戏流程的主函数
function RunAsDisplayer()
{
 local sigThis
 InitDraw
 #挂载各种信号的处理函数
 trap "sig=$sigRotate;" $sigRotate
 trap "sig=$sigLeft;" $sigLeft
 trap "sig=$sigRight;" $sigRight
 trap "sig=$sigDown;" $sigDown
 trap "sig=$sigAllDown;" $sigAllDown
 trap "ShowExit;" $sigExit
 while :
 do
 #根据当前的速度级iLevel不同，设定相应的循环的次数
 for ((i = 0; i < 21 - iLevel; i++))
 do
 sleep 0.02
 sigThis=$sig
 sig=0
 #根据sig变量判断是否接受到相应的信号
 if ((sigThis == sigRotate)); then BoxRotate;  #旋转
 elif ((sigThis == sigLeft)); then BoxLeft;    #左移一列
 elif ((sigThis == sigRight)); then BoxRight;  #右移一列
 elif ((sigThis == sigDown)); then BoxDown;    #下落一行
 elif ((sigThis == sigAllDown)); then BoxAllDown;   #下落到底
 fi
 done
 #kill -$sigDown $$
 BoxDown     #下落一行
 done
}

#BoxMove(y, x), 测试是否可以把移动中的方块移到(x, y)的位置, 返回0则可以, 1不可以
function BoxMove()
{
 local j i x y xTest yTest
 yTest=$1
 xTest=$2
 for ((j = 0; j < 8; j += 2))
 do
 ((i = j + 1))
 ((y = ${boxCur[$j]} + yTest))
 ((x = ${boxCur[$i]} + xTest))
 if (( y < 0 || y >= iTrayHeight || x < 0 || x >= iTrayWidth))
 then
 #撞到墙壁了
 return 1
 fi
 if ((${iMap[y * iTrayWidth + x]} != -1 ))
 then
 #撞到其他已经存在的方块了
 return 1
 fi
 done
 return 0;
}

#将当前移动中的方块放到背景方块中去,
#并计算新的分数和速度级。(即一次方块落到底部)
function Box2Map()
{
 local j i x y xp yp line
 #将当前移动中的方块放到背景方块中去
 for ((j = 0; j < 8; j += 2))
 do
 ((i = j + 1))
 ((y = ${boxCur[$j]} + boxCurY))
 ((x = ${boxCur[$i]} + boxCurX))
 ((i = y * iTrayWidth + x))
 iMap[$i]=$cBoxCur
 done
 #消去可被消去的行
 line=0
 for ((j = 0; j < iTrayWidth * iTrayHeight; j += iTrayWidth))
 do
 for ((i = j + iTrayWidth - 1; i >= j; i--))
 do
 if ((${iMap[$i]} == -1)); then break; fi
 done
 if ((i >= j)); then continue; fi
 ((line++))
 for ((i = j - 1; i >= 0; i--))
 do
 ((x = i + iTrayWidth))
 iMap[$x]=${iMap[$i]}
 done
 for ((i = 0; i < iTrayWidth; i++))
 do
 iMap[$i]=-1
 done
 done
 if ((line == 0)); then return; fi
 #根据消去的行数line计算分数和速度级
 ((x = iLeft + iTrayWidth * 2 + 7))
 ((y = iTop + 11))
 ((iScore += line * 2 - 1))
 #显示新的分数
 echo -ne "[1m[3${cScoreValue}m[${y};${x}H${iScore} "
 if ((iScore % iScoreEachLevel < line * 2 - 1))
 then
 if ((iLevel < 20))
 then
 ((iLevel++))
 ((y = iTop + 14))
 #显示新的速度级
 echo -ne "[3${cScoreValue}m[${y};${x}H${iLevel} "
 fi
 fi
 echo -ne "[0m"

 #重新显示背景方块
 for ((y = 0; y < iTrayHeight; y++))
 do
 ((yp = y + iTrayTop + 1))
 ((xp = iTrayLeft + 1))
 ((i = y * iTrayWidth))
 echo -ne "[${yp};${xp}H"
 for ((x = 0; x < iTrayWidth; x++))
 do
 ((j = i + x))
 if ((${iMap[$j]} == -1))
 then
 echo -ne " "
 else
 echo -ne "[1m[7m[3${iMap[$j]}m[4${iMap[$j]}m[][0m"
 fi
 done
 done
}

#下落一行
function BoxDown()
{
 local y s
 ((y = boxCurY + 1))       #新的y坐标
 if BoxMove $y $boxCurX    #测试是否可以下落一行
 then
 s="`DrawCurBox 0`"        #将旧的方块抹去
 ((boxCurY = y))
 s="$s`DrawCurBox 1`"      #显示新的下落后方块
 echo -ne $s
 else
 #走到这儿, 如果不能下落了
 Box2Map           #将当前移动中的方块贴到背景方块中
 RandomBox         #产生新的方块
 fi
}
#左移一列
function BoxLeft()
{
 local x s
 ((x = boxCurX - 1))
 if BoxMove $boxCurY $x
 then
 s=`DrawCurBox 0`
 ((boxCurX = x))
 s=$s`DrawCurBox 1`
 echo -ne $s
 fi
}
#右移一列
function BoxRight()
{
 local x s
 ((x = boxCurX + 1))
 if BoxMove $boxCurY $x
 then
 s=`DrawCurBox 0`
 ((boxCurX = x))
 s=$s`DrawCurBox 1`
 echo -ne $s
 fi
}

#下落到底
function BoxAllDown()
{
 local k j i x y iDown s
 iDown=$iTrayHeight
 #计算一共需要下落多少行
 for ((j = 0; j < 8; j += 2))
 do
 ((i = j + 1))
 ((y = ${boxCur[$j]} + boxCurY))
 ((x = ${boxCur[$i]} + boxCurX))
 for ((k = y + 1; k < iTrayHeight; k++))
 do
 ((i = k * iTrayWidth + x))
 if (( ${iMap[$i]} != -1)); then break; fi
 done
 ((k -= y + 1))
 if (( $iDown > $k )); then iDown=$k; fi
 done
 s=`DrawCurBox 0`         #将旧的方块抹去
 ((boxCurY += iDown))
 s=$s`DrawCurBox 1`       #显示新的下落后的方块
 echo -ne $s
 Box2Map                  #将当前移动中的方块贴到背景方块中
 RandomBox                #产生新的方块
}

#旋转方块
function BoxRotate()
{
 local iCount iTestRotate boxTest j i s
 iCount=${countBox[$iBoxCurType]}    #当前的方块经旋转可以产生的样式的数目
 #计算旋转后的新的样式
 ((iTestRotate = iBoxCurRotate + 1))
 if ((iTestRotate >= iCount))
 then
 ((iTestRotate = 0))
 fi
 #更新到新的样式, 保存老的样式(但不显示)
 for ((j = 0, i = (${offsetBox[$iBoxCurType]} + $iTestRotate) * 8; j < 8; j++, i++))
 do
 boxTest[$j]=${boxCur[$j]}
 boxCur[$j]=${box[$i]}
 done
 if BoxMove $boxCurY $boxCurX #测试旋转后是否有空间放的下
 then
 #抹去旧的方块
 for ((j = 0; j < 8; j++))
 do
 boxCur[$j]=${boxTest[$j]}
 done
 s=`DrawCurBox 0`
 #画上新的方块
 for ((j = 0, i = (${offsetBox[$iBoxCurType]} + $iTestRotate) * 8; j < 8; j++, i++))
 do
 boxCur[$j]=${box[$i]}
 done
 s=$s`DrawCurBox 1`
 echo -ne $s
 iBoxCurRotate=$iTestRotate
 else
 #不能旋转，还是继续使用老的样式
 for ((j = 0; j < 8; j++))
 do
 boxCur[$j]=${boxTest[$j]}
 done
 fi
}

#DrawCurBox(bDraw), 绘制当前移动中的方块, bDraw为1, 画上, bDraw为0, 抹去方块。
function DrawCurBox()
{
 local i j t bDraw sBox s
 bDraw=$1
 s=""
 if (( bDraw == 0 ))
 then
 sBox="  "
 else
 sBox="[]"
 s=$s"[1m[7m[3${cBoxCur}m[4${cBoxCur}m"
 fi
 for ((j = 0; j < 8; j += 2))
 do
 ((i = iTrayTop + 1 + ${boxCur[$j]} + boxCurY))
 ((t = iTrayLeft + 1 + 2 * (boxCurX + ${boxCur[$j + 1]})))
 #[y;xH, 光标到(x, y)处
 s=$s"[${i};${t}H${sBox}"
 done
 s=$s"[0m"
 echo -n $s
}

#更新新的方块
function RandomBox()
{
 local i j t
 #更新当前移动的方块
 iBoxCurType=${iBoxNewType}
 iBoxCurRotate=${iBoxNewRotate}
 cBoxCur=${cBoxNew}
 for ((j = 0; j < ${#boxNew[@]}; j++))
 do
 boxCur[$j]=${boxNew[$j]}
 done

 #显示当前移动的方块
 if (( ${#boxCur[@]} == 8 ))
 then
 #计算当前方块该从顶端哪一行"冒"出来
 for ((j = 0, t = 4; j < 8; j += 2))
 do
 if ((${boxCur[$j]} < t)); then t=${boxCur[$j]}; fi
 done
 ((boxCurY = -t))
 for ((j = 1, i = -4, t = 20; j < 8; j += 2))
 do
 if ((${boxCur[$j]} > i)); then i=${boxCur[$j]}; fi
 if ((${boxCur[$j]} < t)); then t=${boxCur[$j]}; fi
 done
 ((boxCurX = (iTrayWidth - 1 - i - t) / 2))
 #显示当前移动的方块
 echo -ne `DrawCurBox 1`
 #如果方块一出来就没处放，Game over!
 if ! BoxMove $boxCurY $boxCurX
 then
 kill -$sigExit ${PPID}
 ShowExit
 fi
 fi

 #清除右边预显示的方块
 for ((j = 0; j < 4; j++))
 do
 ((i = iTop + 1 + j))
 ((t = iLeft + 2 * iTrayWidth + 7))
 echo -ne "[${i};${t}H "
 done
 #随机产生新的方块
 ((iBoxNewType = RANDOM % ${#offsetBox[@]}))
 ((iBoxNewRotate = RANDOM % ${countBox[$iBoxNewType]}))
 for ((j = 0, i = (${offsetBox[$iBoxNewType]} + $iBoxNewRotate) * 8; j < 8; j++, i++))
 do
 boxNew[$j]=${box[$i]};
 done
 ((cBoxNew = ${colorTable[RANDOM % ${#colorTable[@]}]}))
 #显示右边预显示的方块
 echo -ne "[1m[7m[3${cBoxNew}m[4${cBoxNew}m"
 for ((j = 0; j < 8; j += 2))
 do
 ((i = iTop + 1 + ${boxNew[$j]}))
 ((t = iLeft + 2 * iTrayWidth + 7 + 2 * ${boxNew[$j + 1]}))
 echo -ne "[${i};${t}H[]"
 done
 echo -ne "[0m"
}

#初始绘制
function InitDraw()
{
 clear
 RandomBox #随机产生方块，这时右边预显示窗口中有方快了
 RandomBox #再随机产生方块，右边预显示窗口中的方块被更新，原先的方块将开始下落
 local i t1 t2 t3
 #显示边框
 echo -ne "[1m"
 echo -ne "[3${cBorder}m[4${cBorder}m"
 ((t2 = iLeft + 1))
 ((t3 = iLeft + iTrayWidth * 2 + 3))
 for ((i = 0; i < iTrayHeight; i++))
 do
 ((t1 = i + iTop + 2))
 echo -ne "[${t1};${t2}H||"
 echo -ne "[${t1};${t3}H||"
 done
 ((t2 = iTop + iTrayHeight + 2))
 for ((i = 0; i < iTrayWidth + 2; i++))
 do
 ((t1 = i * 2 + iLeft + 1))
 echo -ne "[${iTrayTop};${t1}H=="
 echo -ne "[${t2};${t1}H=="
 done
 echo -ne "[0m"

 #显示"Score"和"Level"字样
 echo -ne "[1m"
 ((t1 = iLeft + iTrayWidth * 2 + 7))
 ((t2 = iTop + 10))
 echo -ne "[3${cScore}m[${t2};${t1}HScore"
 ((t2 = iTop + 11))
 echo -ne "[3${cScoreValue}m[${t2};${t1}H${iScore}"
 ((t2 = iTop + 13))
 echo -ne "[3${cScore}m[${t2};${t1}HLevel"
 ((t2 = iTop + 14))
 echo -ne "[3${cScoreValue}m[${t2};${t1}H${iLevel}"
 echo -ne "[0m"
}

#退出时显示GameOVer!
function ShowExit()
{
 local y
 ((y = iTrayHeight + iTrayTop + 3))
 echo -e "[${y};0HGameOver![0m"
 exit
}

#显示用法.
function Usage
{
 cat << EOF
Usage: $APP_NAME
Start tetris game.
 -h, --help display this help and exit
 --version output version information and exit
EOF
}

#游戏主程序在这儿开始.
if [[ "$1" == "-h" || "$1" == "--help" ]]; then
 Usage
elif [[ "$1" == "--version" ]]; then
 echo "$APP_NAME $APP_VERSION"
elif [[ "$1" == "--show" ]]; then
 #当发现具有参数--show时，运行显示函数
 RunAsDisplayer
else
 bash $0 --show& #以参数--show将本程序再运行一遍
 RunAsKeyReceiver $! #以上一行产生的进程的进程号作为参数
fi