方法一：getconf LONG_BIT
如果是32b則輸出32，64b則輸出64

[root@centos fation]# getconf LONG_BIT
32

方法二：uname -a

執行後的結果中輸出了x86_64，說明該機器是64位的，否則代表該機器是32位的

[root@centos fation]# uname -a
Linux centos 2.6.32-573.el6.i686 #1 SMP Thu Jul 23 12:37:35 UTC 2015 i686 i686 i386 GNU/Linux

方法三：file /sbin/init 或者 file /bin/ls

[root@centos fation]# file /sbin/init
/sbin/init: ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.18, stripped

[root@centos fation]# file /bin/ls
/bin/ls: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared
 
 libs), for GNU/Linux 2.6.18, stripped