下面这段代码得不到想要的结果，但是把>>号前面加上一个空格就可以了，不知道为什么？
echo {>>test.txt
echo if ($2==2) $2=4 >>test.txt
echo else if ($2==1) $2=2 >>test.txt
echo else if ($2==3) $2=5>>test.txt
echo else if ($2==4) $2=3 >>test.txt
echo else $2=1>>test.txt
echo if ($13==1) $13=5>>test.txt
echo else if ($13==2) $13=4>>test.txt
echo else if ($13==3) $13=3>>test.txt
echo else if ($13==4) $13=2>>test.txt
echo else $13=1>>test.txt
echo if ($16==1) $16=5>>test.txt
echo else if ($16==2) $16=4>>test.txt
echo else if ($16==3) $16=3>>test.txt
echo else if ($16==4) $16=2>>test.txt
echo else $16=1>>test.txt
echo if ($19==1) $19=5>>test.txt
echo else if ($19==2) $19=4>>test.txt
echo else if ($19==3) $19=3>>test.txt
echo else if ($19==4) $19=2>>test.txt
echo else $19=1>>test.txt
echo if ($22==1) $22=5>>test.txt
echo else if ($22==2) $22=4>>test.txt
echo else if ($22==3) $22=3>>test.txt
echo else if ($22==4) $22=2>>test.txt
echo else $22=1>>test.txt
echo }>>test.txt
