Trying to make command like "Shell" with commands with RichTextBox - vb.net

Question

Trying to make command like Shell with commands with RichTextBox.
Can anyone make a simple way to make it?
im searching for this on entire webs can't find a way to make it.
So its should be like any terminal / shell / console app
So i can simply add custom commands like whatismyip its shows me my ip address etc.
Should be like this.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
For I As Integer = 0 To RichTextBox1.Lines.Count - 1
Dim Parts() As String = RichTextBox1.Lines(I).Split
Select Case Parts(0).ToUpper
Case "getip"
RichTextBox1.AppendText("SYS $~ 127.0.0.1")
Case Else
RichTextBox1.AppendText("SYS $~ Invalid command.")
End Select
Next
End Sub

Answer 1

Try this:
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
commands = New Dictionary(Of String, Func(Of String, IEnumerable(Of String), String))() From _
{ _
{"getip", Function(c, ps) Me.GetIP().ToString()}, _
{"nop", Function(c, ps) "No Command"} _
}
End Sub
Private commands As Dictionary(Of String, Func(Of String, IEnumerable(Of String), String)) = Nothing
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim command = {"nop"}.Concat(Me.RichTextBox1.Lines) _
.Reverse().First(Function(l) Not [String].IsNullOrWhiteSpace(l))
If (If(Me.RichTextBox1.Lines.LastOrDefault(), "")).Length > 0 Then
Me.RichTextBox1.AppendText(Environment.NewLine)
End If
Dim parts = command.Split({" "c}, StringSplitOptions.RemoveEmptyEntries)
Dim result = "Invalid Command"
If commands.ContainsKey(parts(0).ToLower()) Then
result = commands(parts(0))(parts(0), parts.Skip(1).ToArray())
End If
Me.RichTextBox1.AppendText("SYS $~ " + result)
End Sub
Private Function GetIP() As String
Dim host As IPHostEntry
Dim localIP As String = "?"
host = Dns.GetHostEntry(Dns.GetHostName())
For Each ip As IPAddress In host.AddressList
If ip.AddressFamily = AddressFamily.InterNetwork Then
localIP = ip.ToString()
End If
Next
Return localIP
End Function
You'll need to add the following imports:
Imports System.Net
Imports System.Net.Sockets
Then you can just build out the dictionary for each of your commands.