How to call major or minor on dev_t using Swift

Question

I obtained a value of type dev_t and I would like to access to the major and minor versions number of it, unfortunately while in C you would call major(theValue) or minor(theValue) they aren't defined in Swift (probably because they are just macros ?).

How should I do this ?

Thank you

Answer 1

dev_t is an signed 32-bit integer. major returns the most significant 8-bits and minor returns the least significant 24-bits.

let x: dev_t = 0x12345678

func major(_ x: dev_t) -> Int32 {
    return (x >> 24) & 0xff
}

func minor(_ x: dev_t) -> Int32 {
    return x & 0xffffff
}

print(String(major(x), radix: 16))
print(String(minor(x), radix: 16))

Output:

12
345678