How to extract specific bits from a number in C?

Question

I need to extract specific part (no of bits) of a short data type in C.

For Example I have a binary of 52504 as 11001101000 11000 and I want First 6 (

Answer 1

//To get value from specific position 'pos' to 'pos+offset' in number 'value'

#define bitGet(value, offset, pos) (((1ull << offset) - 1) & (value >> (pos - 1)))

//Set value 'newval' from position 'pos' to 'pos+offset' in number 'value'

#define bitSet(value, offset, pos, newval)  \
(~(((1ull << offset) - 1) << (pos - 1)) & value) | ((((1ull << offset) - 1) & newval) << (pos - 1))