如果有x86_64就是64位的，没有就是32位的

2.# uname -m
x86_64

3.# arch
x86_6

如何查看ubuntu版本号：

1. # lsb_release -a

No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 12.04 LTS
Release: 12.04
Codename: precise

2. # cat /etc/lsb-release

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=12.04
DISTRIB_CODENAME=precise
DISTRIB_DESCRIPTION="Ubuntu 12.04 LTS"