IOS Check Tcp Port Can use

check.swift

    func tcpPortIsCanUse(port: in_port_t) -> Bool {
        let socketFileDescriptor = socket(AF_INET, SOCK_STREAM, 0)
        if socketFileDescriptor == -1 {
            return false
        }
        defer {
            Darwin.shutdown(socketFileDescriptor, SHUT_RDWR)
            close(socketFileDescriptor)
        }

        var addr = sockaddr_in()
        let sizeOfSockkAddr = MemoryLayout<sockaddr_in>.size
        addr.sin_len = __uint8_t(sizeOfSockkAddr)
        addr.sin_family = sa_family_t(AF_INET)
        addr.sin_port = Int(OSHostByteOrder()) == OSLittleEndian ? _OSSwapInt16(port) : port
        addr.sin_addr = in_addr(s_addr: inet_addr("0.0.0.0"))
        addr.sin_zero = (0, 0, 0, 0, 0, 0, 0, 0)
        var bind_addr = sockaddr()
        memcpy(&bind_addr, &addr, Int(sizeOfSockkAddr))

        if Darwin.bind(socketFileDescriptor, &bind_addr, socklen_t(sizeOfSockkAddr)) == -1 {
            return false
        }
        if listen(socketFileDescriptor, SOMAXCONN) == -1 {
            return false
        }
        
        return true
    }