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@cheynewallace
Last active July 6, 2024 12:18
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C# Get Active Ports and Associated Process Names. This code will parse the output from a "netstat -a -n -o" and retrieve a list of active listening ports, along with the associated PID. The PID is then resolved to a process name so we can see exactly which port is attached to which process.
// ===============================================
// The Method That Parses The NetStat Output
// And Returns A List Of Port Objects
// ===============================================
public static List<Port> GetNetStatPorts()
{
var Ports = new List<Port>();
try {
using (Process p = new Process()) {
ProcessStartInfo ps = new ProcessStartInfo();
ps.Arguments = "-a -n -o";
ps.FileName = "netstat.exe";
ps.UseShellExecute = false;
ps.WindowStyle = ProcessWindowStyle.Hidden;
ps.RedirectStandardInput = true;
ps.RedirectStandardOutput = true;
ps.RedirectStandardError = true;
p.StartInfo = ps;
p.Start();
StreamReader stdOutput = p.StandardOutput;
StreamReader stdError = p.StandardError;
string content = stdOutput.ReadToEnd() + stdError.ReadToEnd();
string exitStatus = p.ExitCode.ToString();
if (exitStatus != "0") {
// Command Errored. Handle Here If Need Be
}
//Get The Rows
string[] rows = Regex.Split(content, "\r\n");
foreach (string row in rows) {
//Split it baby
string[] tokens = Regex.Split(row, "\\s+");
if (tokens.Length > 4 && (tokens[1].Equals("UDP") || tokens[1].Equals("TCP"))) {
string localAddress = Regex.Replace(tokens[2], @"\[(.*?)\]", "1.1.1.1");
Ports.Add(new Port {
protocol = localAddress.Contains("1.1.1.1") ? String.Format("{0}v6",tokens[1]) : String.Format("{0}v4",tokens[1]),
port_number = localAddress.Split(':')[1],
process_name = tokens[1] == "UDP" ? LookupProcess(Convert.ToInt16(tokens[4])) : LookupProcess(Convert.ToInt16(tokens[5]))
});
}
}
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message)
}
return Ports;
}
public static string LookupProcess(int pid)
{
string procName;
try { procName = Process.GetProcessById(pid).ProcessName; }
catch (Exception) { procName = "-";}
return procName;
}
// ===============================================
// The Port Class We're Going To Create A List Of
// ===============================================
public class Port
{
public string name
{
get
{
return string.Format("{0} ({1} port {2})",this.process_name, this.protocol, this.port_number);
}
set { }
}
public string port_number { get; set; }
public string process_name { get; set; }
public string protocol { get; set; }
}
@magnusjjj
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A process number can be higher than int16 :).

Is there a license for this gist?

@cheynewallace
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Author

Sorry guys, I wrote this code about a decade ago or more. I havn't written any C# since back around then so do with it as you will.
There's no license here, use it, modify it, if it helps you out, do what you want with it.

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