Let's say I have a variable that is char type and is equal to 'A' which is 65 in decimal and 01000001 in binary. How can I access the individual bits in that variable? For example, accessing bit 0 would result in 1. How can I do this in C?

I would do it like this in C++
template <class T>
bool retrievebit(T source, int bit)
{
if(bit > (sizeof(T)*8)) throw "Too large";
return ((source >> (bit-1)) & 1);
}
I haven't tested that and it will only work for types that have >> defined as the left shift, but  otherwise it should be good.

EDIT: I just saw this was in C I'll rewrite this real quick to be C code

In c for just char it would be like this
int retrievebit(char source, int bit)
{
if(bit > 8)) return -1;
return ((source >> (bit-1)) & 1);
}

Actually, this could work:

Code: [Select]

#define getBit(x,n) x&(1<<n)

Nope
#define getBit(x,n) ((x&(1<<n))>>n)

Or even
#define getBit(x,n) ((x)>>(n)&1)