Swift - Interoperability with c lang

The function is shown below obtains the machine model by calling the sysctlbyname function. 

    func getModelNameBySysCtl() -> String{

        let name = "hw.machine"

        var size: Int = 0

        var result: String = ""

        var funcRet: Int32 = -1

        sysctlbyname(

            name,

            nil,

            &size,

            nil,

            0

        )

        if size > 0 {

            let valuePointer = UnsafeMutablePointer<CChar>.allocate(capacity: size)

            valuePointer.initialize(to: 0)

            funcRet = sysctlbyname(

                name,

                valuePointer,

                &size,

                nil,

                0

            )

            if funcRet == 0{

                result = String(cString: valuePointer)

            }

            valuePointer.deinitialize(count: size)

            valuePointer.deallocate()

        }

        return result

    }

Points of the above code

• String to UnsafePointer<CChar>
• Manage UnsafeMutablePointer<CChar>