[Linux] Check linux kernel is 32 bit or 64 bit

Problem:

How to check linux kernel is 32 bit or 64 bit

Command:
Input following command in terminal.

uname -m
OR
file /bin/bash


Example:

allen@www ~/work$ file /bin/bash
/bin/bash: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.15, stripped

allen@www ~/work$ uname -m
x86_64

Reference:
http://www.linuxquestions.org/questions/linux-general-1/how-to-check-linux-kernel-is-32-bit-or-64-bit-612352/
http://blog.longwin.com.tw/2011/01/linux-check-32-64-bits-2011/