Class PortService

Namespace

McServerLauncher.Services

Assembly

McServerLauncher.dll

Checks which ports are in use on the machine (by any application) and helps find the next free one. TCP and UDP are asked separately because they are separate namespaces.

public class PortService

Inheritance

object

PortService

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Methods

FindFreePort(int, ISet<int>)

First free port from start that is not in use by the system nor in the alsoAvoid set (e.g. ports of other registered servers). Returns null if every port up to 65535 is taken, so the caller can react instead of silently getting a busy port back. The system's listener table is snapshotted once for the whole scan (instead of re-queried per port).

public int? FindFreePort(int start, ISet<int> alsoAvoid)

Parameters

start int

alsoAvoid ISet<int>

Returns

int?

FindFreeUdpPort(int, ISet<int>)

First free UDP port from start, skipping alsoAvoid. Null when everything up to 65535 is taken.

public int? FindFreeUdpPort(int start, ISet<int> alsoAvoid)

Parameters

start int

alsoAvoid ISet<int>

Returns

int?

FindFreeUdpPort(int, ISet<int>, out bool)

First free UDP port from start, skipping alsoAvoid. Null when everything up to 65535 is taken. systemPortsRead says whether the system's UDP table could actually be read.

public int? FindFreeUdpPort(int start, ISet<int> alsoAvoid, out bool systemPortsRead)

Parameters

start int

alsoAvoid ISet<int>

systemPortsRead bool

Returns

int?

Remarks

The flag exists because the two answers used to be indistinguishable. When the table cannot be queried every port looks free, so the search returns start — the same value it returns when it has genuinely checked and the port is available. A caller handing that port to Geyser could not tell "19132 is free" from "I have no idea what is bound", and the difference only surfaced later as a Geyser that silently failed to bind.

GetListeningPid(int)

PID of the process listening (LISTEN) on that TCP port, or null.

public int? GetListeningPid(int port)

Parameters

port int

Returns

int?

IsPortInUse(int)

True if any system process is listening on that TCP port.

public bool IsPortInUse(int port)

Parameters

port int

Returns

bool

IsUdpPortInUse(int)

True if any system process is listening on that UDP port.

public bool IsUdpPortInUse(int port)

Parameters

port int

Returns

bool