Check out example codes for "32bit or 64bit". It will help you in understanding the concepts better.

Code Example 1

grep flags /proc/cpuinfo


Explanation(only in linux):
Look for "lm" in the command output. If lm is found in the output, then the CPU is 64-bit. If you don't see lm or see i386, i486, i586, or i686 in the output, then the CPU is 32-bit. Below is an example output of the above line with lm in the information.

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