[RESOLVED] Sending Text To Telnet Without Using Sendkeys

I am trying to send text to a telnet window without using sendkeys.send().

I am new to API but not new to programming and I am using C#.


I figured out how to get the hWnd of the telnet session but I cannot figure out how to send text to the window. Heres what I have so far.

SendMessage(hWndTnet, WM_SETTEXT, 0, "testing");
SendMessage(hWndTnet, WM_CHAR, 13, null);

What am I doing wrong?


Thanks a bunch for any help :thumb:

What type of telnet window is it?

And have you tried WM_KEYDOWN or WM_KEYUP?

thanks for the reply

its the windows xp telnet from C:\WINDOWS\system32\telnet.exe

im really new to api.
how do i find the const values for WM_KEYDOWN and WM_KEYUP?
heres what I have so far

public static int GW_HWNDNEXT = 2;
public static int GW_CHILD = 5;
public static int GW_OWNER = 4;
public static int GWL_HWNDPARENT = -8;
public static int WM_SETTEXT = 12;
public const int HWND_MESSAGE = -3;
public const int WM_CHAR = 258;

I also tried to redirect the standard I/O but telnet will not allow it.

I basically need to be able to send text to a telnet.exe process without using appactivate/sendkeys because I will have 30+ telnet processes open at one time. I am trying to automate a tedious process here at my job.

The quickest way is just to do a Google search "#define " followed by the name of the constant. For example, "#define WM_KEYDOWN". And then grab the most common hex value you see. It's pretty easy, in this case you see the text #define WM_KEYDOWN 0x100 all down the page, so that's the value :)

Code:

---

const int WM_KEYDOWN = 0x100;

---

i just tried

public const int WM_KEYDOWN = 0x100;

SendMessage(hWndTnet, WM_KEYDOWN, 0, "testing");

but it did not work...

With KEYDOWN you can only do a character at a time.

http://msdn.microsoft.com/library/de...wm_keydown.asp

Quote:

---

wParam
Specifies the virtual-key code of the nonsystem key.

---

so

Code:

---

SendMessage(hWndTnet, WM_KEYDOWN, Keys.T, 0);

---

would send a T character, hopefully :)

Thanks for the help.

SendMessage(hWndTnet, WM_KEYDOWN, 0,Keys.T);

I tried and got this error message.

Error 1 The best overloaded method match for 'Send_Window_Test.Form1.SendMessage(int, int, int, string)' has some invalid arguments Form1.cs 70 13 Send Window Test

Error 2 Argument '4': cannot convert from 'System.Windows.Forms.Keys' to 'string' Form1.cs 70 53 Send Window Test


so then i tried using the .ToString() but that did not work either.

SendMessage(hWndTnet, WM_KEYDOWN, 0,Keys.T.ToString());

I also tried this but it did not work either.

SendMessage(hWndTnet, WM_KEYDOWN, Keys.T, null);

and

SendMessage(hWndTnet, WM_KEYDOWN, Convert.ToInt32(Keys.T), null);

oh, you need to change your SendMessage declaration so all the parameters are int's ;)

Thanks again for helping.
Is there any way I can get you to take a look at the code cause it still doesnt work after makeing all parms type int
Thanks alot.

the telnet window is nothing more than a comand console window so what works is posting WM_CHAR messages. Here is code for VB6, you'll have to make changes for VB.NET

VB Code:

Option Explicit
 
Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" ( _
    ByVal lpClassName As String, _
    ByVal lpWindowName As String _
) As Long
 
Private Declare Function PostMessage Lib "user32" Alias "PostMessageA" ( _
    ByVal hwnd As Long, _
    ByVal wMsg As Long, _
    ByVal wParam As Long, _
    ByVal lParam As Long _
) As Long
 
Private Const WM_CHAR = &H102
 
Private Sub Command1_Click()
Dim hWndCMD As Long
Dim x As String
Dim i As Integer
   'Change to your caption below
    hWndCMD = FindWindow("ConsoleWindowClass", "C:\WINDOWS\system32\cmd.exe")
    If hWndCMD = 0 Then Stop
 
    For i = 1 To Len(Text1.Text)
        x = Mid(Text1.Text, i, 1)
        PostMessage hWndCMD, WM_CHAR, Asc(x), 0&
    Next i
        PostMessage hWndCMD, WM_CHAR, Asc(vbCr), 0&
        PostMessage hWndCMD, WM_CHAR, Asc(vbLf), 0&
    
End Sub

See I didn't know what I was doing :)

Appropriately converted!

Code:

---

[DllImport("user32", EntryPoint = "FindWindowA")]
private static extern IntPtr FindWindow(
    [MarshalAs(UnmanagedType.LPStr)] string lpClassName,
    [MarshalAs(UnmanagedType.LPStr)] string lpWindowName
);

[DllImport("user32", EntryPoint = "PostMessageA")]
private static extern int PostMessage(
    IntPtr hWnd,
    int uMsg,
    int wParam,
    int lParam
);

private const int WM_CHAR = 0x102;

private void Command1_Click()
{
    // you will need to change this line to find the telnet window
    IntPtr hWndCMD = FindWindow("ConsoleWindowClass", String.Empty);
   
    byte[] chars = (new System.Text.ASCIIEncoding()).GetBytes(Text1.Text);

    for (int i = 0; i < chars.Length; i++)
    {
        PostMessage(hWndCMD, WM_CHAR, (int)chars[i], 0);
    }
   
    PostMessage(hWndCMD, WM_CHAR, 10, 0);
    PostMessage(hWndCMD, WM_CHAR, 13, 0);
}

---

I gotta git me some of that .NET stuff. :)

Wow your good. It does work with a ConsoleWindowClass but not with a TelnetClient?

This code works

IntPtr hWndCMD = FindWindow("ConsoleWindowClass", @"C:\WINDOWS\system32\cmd.exe");


but the one for telnet doesnt?
IntPtr hWndCMD = FindWindow("TelnetClient", @"C:\WINDOWS\system32\telnet.exe");


Is there any way to get it to work directly with the telnet window?


Thanks for all the help.

It works for me in VB6

VB Code:

hWndCMD = FindWindow("ConsoleWindowClass", "C:\WINDOWS\system32\telnet.exe")

I was telling it to look for the "TelnetClient" because thats how the program is listed under spy++. I have alot to learn about API.

When you use ConsoleWindowClass it works.
Thanks everyone for getting this issue resolved.

No problems,

The ConsoleWindowClass is probably within the TelnetClient window.