How to determine given OS in 32 bit or 64 bit in Linux

Type the following simple command in your linux boxes:

# uname-m

If it 32 bit os the output would  be  follow:

i686   ==> 32-bit kernel

If it 64 bit os the output would be follow:

x86_64 ==> 64-bit kernel

Or

 can use following command to check the OS versions:

# uname -a

# getconf LONG_BIT

# cat /proc/cpuinfo