ubuntu14.04(64位)运行32位程序

ubuntu14.04出来有段时间了，今天心血来潮把12.04版本升级到了14.04版本，升级后悲剧了，32位的程序运行不起来了。各种百度google，查到最多的是

sudo -i
cd /etc/apt/sources.list.d
echo "debhttp://archive.ubuntu.com/ubuntu/ raring main restricted universe multiverse">ia32-libs-raring.list
apt-get update
apt-get installia32-libs
rm ia32-libs-raring.list
apt-get update
exit

但是我在执行update的时候提示

W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/raring-security/universe/source/Sources 404  Not Found [IP: 91.189.88.153 80]

raring是13.04版本代号，现在已经不维护了，所以替换成12.04代号，步骤如下

sudo -i
cd /etc/apt/sources.list.d
echo "debhttp://archive.ubuntu.com/ubuntu/ precise main restricted universe multiverse">ia32-libs-raring.list
apt-get update
apt-get installia32-libs
rm ia32-libs-raring.list
apt-get update
exit

经过上述操作，一切大功告成，终于可以正常运行了。