如何将Bitwise用于安全组

Question

I'm sure i've done this before, but I can't remember how to do it and I cannot find any help.

If I have the following security access:

1: Read
2: Write
4: Delete
8: View

A user can have a combination of any of these, say Write and View, so their security number would be 10.

How can I check it against each security group to see if they have access?

I thought it was 2 MOD 10 but this doesn't appear to work.

What is the simplest way to approach this issue? Am I missing a bitwise operation?

Answer 1

您将AND与适用的数字进行核对，然后检查它是否大于0，即10＆2> 0，因此您具有写许可权。