how to identify 32 vs 64 bit CPU?

Rick Stevens rstevens at internap.com
Thu Aug 9 17:24:25 UTC 2007


On Thu, 2007-08-09 at 17:50 +0100, Chris Jones wrote:
> > How about uname?  `uname -a` gives all of it.  See `man uname` for subsets
> > and the ordering of the "-a" output.  If you need more than just x86, I
> > think any solution will be a bit involved.
> 
> AFAIK, uname only tells you what you are running, not what you *could* 
> run. I.e. you couldn't tell the diffrence between a 32 bit os on a 64 
> bit capable machine or a 32 bit only machine.

If you get a result from 

    cat /proc/cpuinfo | grep " lm "

you're on a 64-bit processor regardless whether it's a 32- or 64-bit OS.
If you want to know if the OS is 64-bit, then a result from 

	uname -a | grep 64

would indicate a 64-bit OS.


Stupid shell script:

	#!/bin/bash
	echo -n "Running "
	RES=`uname -a | grep 64`
	if [ $? -eq 0 ]; then
	    echo -n "64-bit "
	else
	    echo -n "32-bit "
	fi
	echo -n "operating system on a "
	RES=`cat /proc/cpuinfo | grep " lm "`
	if [ $? -eq 0 ]; then
	    echo -n "64-bit "
	else
	    echo -n "32-bit "
	fi
	echo "machine"

Have fun, gang.
----------------------------------------------------------------------
- Rick Stevens, Principal Engineer             rstevens at internap.com -
- CDN Systems, Internap, Inc.                http://www.internap.com -
-                                                                    -
-        Brain:  The organ with which we think that we think.        -
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