Interpreting uname output: 32 or 64 bit?

Question

I used uname command and obtained:

Linux rufusruffcutt 3.2.0-35-generic-pae #55-Ubuntu SMP Wed Dec 5 18:04:39 UTC 2012 i686 i686 i386 GNU/Linux

What do this mean and how can I tell if this is a 32- or 64-bit kernel version?

Answer 1

From man uname:

-a, --all print all information, in the following order, except omit -p and -i if unknown:

   -s, --kernel-name
          print the kernel name

   -n, --nodename
          print the network node hostname

   -r, --kernel-release
          print the kernel release

   -v, --kernel-version
          print the kernel version

   -m, --machine
          print the machine hardware name

   -p, --processor
          print the processor type or "unknown"

   -i, --hardware-platform
          print the hardware platform or "unknown"

   -o, --operating-system
          print the operating system

So in your case:

Linux       rufusruffcutt 3.2.0-35-generic-pae #55-Ubuntu SMP Wed Dec 5 18:04:39 UTC 2012 i686 i686 i386 GNU/Linux      

So you have a machine hw which is i686, a processor type i686, and a hw platform which is i386.

In Ubuntu builds, i386 are the 32-bit builds; in a 64-bit system they would be x86_64.

Using uname -i should give you just the hardware platform.

Answer 2

Instead you can use the getconf command:

getconf LONG_BIT

It will shows you your kernel whether it is 32 bit or 64 bit.

Answer 3

i686 is the name of an Intel processor architecture with 32 bit word length.