lmxopcua/tools/opcuacli-dotnet/Commands/ReadCommand.cs

using CliFx;
using CliFx.Attributes;
using CliFx.Infrastructure;
using Opc.Ua;
using Opc.Ua.Client;

namespace OpcUaCli.Commands;

[Command("read", Description = "Read a value from a node")]
public class ReadCommand : ICommand
{
    /// <summary>
    /// Gets the OPC UA endpoint URL to connect to before reading.
    /// </summary>
    [CommandOption("url", 'u', Description = "OPC UA server endpoint URL", IsRequired = true)]
    public string Url { get; init; } = default!;

    [CommandOption("username", 'U', Description = "Username for authentication")]
    public string? Username { get; init; }

    [CommandOption("password", 'P', Description = "Password for authentication")]
    public string? Password { get; init; }

    /// <summary>
    /// Gets the node identifier whose value should be read.
    /// </summary>
    [CommandOption("node", 'n', Description = "Node ID (e.g. ns=2;s=MyNode)", IsRequired = true)]
    public string NodeId { get; init; } = default!;

    /// <summary>
    /// Connects to the endpoint, reads the target node, and prints the returned value details.
    /// </summary>
    /// <param name="console">The console used to report the read result.</param>
    public async ValueTask ExecuteAsync(IConsole console)
    {
        using var session = await OpcUaHelper.ConnectAsync(Url, Username, Password);

        var node = new NodeId(NodeId);
        var value = await session.ReadValueAsync(node);

        await console.Output.WriteLineAsync($"Node:        {NodeId}");
        await console.Output.WriteLineAsync($"Value:       {value.Value}");
        await console.Output.WriteLineAsync($"Status:      {value.StatusCode}");
        await console.Output.WriteLineAsync($"Source Time: {value.SourceTimestamp:O}");
        await console.Output.WriteLineAsync($"Server Time: {value.ServerTimestamp:O}");
    }
}