用这个看一下： file /bin/ls
如果显示像这样：
/bin/ls: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for GNU/Linux 2.6.0, dynamically linked (uses shared libs), stripped
说明是：32 bit；
如果显示像这样：
/bin/ls: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), for GNU/Linux 2.6.0, dynamically linked (uses shared libs), stripped
这是64 bit.
