func findFreePort() -> UInt16 {
var port: UInt16 = 8000;
let socketFD = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if socketFD == -1 {
//print("Error creating socket: \(errno)")
return port;
}
var hints = addrinfo(
ai_flags: AI_PASSIVE,
ai_family: AF_INET,
ai_socktype: SOCK_STREAM,
ai_protocol: 0,
ai_addrlen: 0,
ai_canonname: nil,
ai_addr: nil,
ai_next: nil
);
var addressInfo: UnsafeMutablePointer<addrinfo>? = nil;
var result = getaddrinfo(nil, "0", &hints, &addressInfo);
if result != 0 {
//print("Error getting address info: \(errno)")
close(socketFD);
return port;
}
result = Darwin.bind(socketFD, addressInfo!.pointee.ai_addr, socklen_t(addressInfo!.pointee.ai_addrlen));
if result == -1 {
//print("Error binding socket to an address: \(errno)")
close(socketFD);
return port;
}
result = Darwin.listen(socketFD, 1);
if result == -1 {
//print("Error setting socket to listen: \(errno)")
close(socketFD);
return port;
}
var addr_in = sockaddr_in();
addr_in.sin_len = UInt8(MemoryLayout.size(ofValue: addr_in));
addr_in.sin_family = sa_family_t(AF_INET);
var len = socklen_t(addr_in.sin_len);
result = withUnsafeMutablePointer(to: &addr_in, {
$0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
return Darwin.getsockname(socketFD, $0, &len);
}
});
if result == 0 {
port = addr_in.sin_port;
}
Darwin.shutdown(socketFD, SHUT_RDWR);
close(socketFD);
return port;
}
