How can I tell if my Linux Redhat machine is running 32 or 64 bit for the Operating System?

How can I tell if my Linux Redhat machine is running 32 or 64 bit for the Operating System?

How can I tell if my machine is running 32 or 64 bit version of the Operating System?

How can I tell is my machine is 32 or 64 bit?

The Operating System command uname -a will provide you that information on Linux.

The output will provide you some insight as to if the Operating System is 32 or 64 bit. 

Example: 

$ uname -a
Linux hostname 2.4.21-4.ELsmp #1 SMP Fri Oct 3 17:32:58 EDT 2003 x86_64 x86_64 x86_64 GNU/Linux

$ uname -a
Linux hostname 2.6.9-55.ELsmp #1 SMP Fri Apr 20 17:03:35 EDT 2007 i686 i686 i386 GNU/Linux

Linux machines that are running 64 bit have the 64 referenced within the result of the uname -a command.
Linux machines that are running 32 bit have a reference like i686 or i386.

Additional information regarding the Linux platform as well as other Operating Systems is available via: 
http://www.stata.com/support/faqs/win/64bit.html

References to Other Documentation:
Progress Article(s):
 What information is required when opening a support case for OpenEdge ABL issues?
 How to determine the Windows 8 and 10 versions from ABL at runtime ?
 ABL/4GL: How to determine the Windows Version, Build and Service pack under which the current 4GL/ABL session is running?
 How to determine the bitness of Windows?

http://www.stata.com/support/faqs/win/64bit.html