More on Using Bitwise Operations

Computing bitmasks

Here is another example of using bitwise operations. We need them for computing bitmasks, which use OR or AND operators to encode or decode values respectively. We’re already familiar with file permission masks in the Unix environment. Let’s suppose that a file has the permissions “-rw-r–r–”. It looks like this in binary:

0000 0110 0100 0100

Let’s suppose that we want to check if the file owner can execute it. We can do that by calculating the bitwise AND for the permission mask and the ...