Looking for Messenger-Like App

[Gary Beene]

I'd like to set up a one-on-one chat with a co-worker. At most, there might be 3 of us in the loop.

Basically a "messenger" app. But looking at the various apps floating around, I'm seeing way more complex/capable apps than I want. Plus,

Does anyone have a suggestion on a very minimal PC-to-PC messaging app? Text only. No video. No Audio. No images. Links may be sent, but active link support is not critical.

I remember such an app for a LAN, but in this case the co-worker is in a different city.

[Gary Beene]

Or, for that matter, if it was easy enough to write something like that in PowerBASIC, I'd be willing to consider that too.

[Pierre Bellisle]

...co-worker is in a different city...
Oops, what I posted was for a lan.
[So stuff removed]

[Bob Carver]

Just use bog-standard Skype/Discord/IRC/etc. You don't have to use features that are above and beyond standard text messaging if that's all you need them for, but they might be nice to have if you decide you want to voice chat or whiteboard in the future

Heck you could even use Twitter DMs or Facebook messaging since those need even less setup

[Jim Fritts]

I'd also be interested in a roll your own IPV6 app. Thanks

[Gary Beene]

Hi Bob!
Yes, I'm using Skype right now, and it works fine for me. But as is the case with a lot of stuff I'm doing right now, folks I'm dealing with suffer from various vision impairments. So I need to be able to control the interface design. Skype is a good example of apps my folks cannot use because of the small size and low color contrast of its GUI design elements (small images/buttons/text, etc.).

Jim,
I may give it a try, but what I'd come up with would likely be very minimal - trivial by comparison of the feature-set any of the current IMs offer. It would suit my needs, but would be feature-poor by today's standards.

[Dale Yarker]

I don't know about setting text size, but ICQ seems alive. I have not used for decade, or more, but was able to go to www.icq.com

[Stuart McLachlan]

ISTM that combining the code in EchoServ and EClient with a suitable dialog would meet your requirements quite easily.

(They can be found in ../Samples/Internet/TCP)

[Joe Caverly]

Or, for that matter, if it was easy enough to write something like that in PowerBASIC, I'd be willing to consider that too.

Hello Gary,
If you don't mind learning a new API, consider, for example, the Twitter API.

A Google search for twitter api vb6 should get you started towards a PB Application.

It's too bad that application developers don't take into consideration that people our age have a more difficult time reading such small print on a screen. However, with your PowerBASIC programming knowledge and skills, you should be able to make your own app.

Note that the Twitter API is just an example. There are other API options.

Joe

[Michael Mattias]

ISTM that combining the code in EchoServ and EClient with a suitable dialog would meet your requirements quite easily.

That was my thought, too, as soon as all the limitations were spelled out. (3 users, all text): A simple TCP application.

OR ... you could pull this off using PCAnywhere (tm), which is not very expensive at all and offers a whole lot of features over and above "chat." I have used the "chat" feature with several of my clients over the years and it works just fine.

OR... I think the major "meeting" software such as GoToMeeting, dimdim, etc all have a feature like this, too; but now you are getting into some significant dollars if you need to set up a "host" or "home" site.

OR... you could always try this other piece of technology called the "telephone." I used that quite effectively for many years before there was such a thing as a world-wide web or a Windows O/S. Hell, I used that before the first personal-sized computers and it worked well then, too. .

MCM

[Paul Purvis]

Gary, I see some web php chat code for download.
I am not sure of your full needs or how well it works.
It seems no matter what you do. There likely needs to be a sever if some kind involved.

[Mike Doty]

Gary,
This should have all the TCP needed.
Each instance is a client and server.
Reverse $Host and $ClientIp on machine 2.
I pulled code out of a program I use as a TCP File Server so it can also be used to send binary.

#PBFORMS CREATED V2.01
$ValidUser = CHR$(0,1) 'username
$Host     = "192.168.0.2"     'my IP or computer name
$ClientIp = "192.168.0.3" 'ip of other machine
%Port = 51234
%TCP_TIMEOUT = 80000
%ListenFileNumber = 9999
%Tcp_Notify = %WM_USER + 4093
GLOBAL ghDlg AS DWORD, gsAll AS STRING 'only for testing
THREADED tTCPFileNumber AS LONG 'each connection
'-----------------------------------------------------------------------------------
#PBFORMS BEGIN INCLUDES
#INCLUDE ONCE "WIN32API.INC"
#PBFORMS END INCLUDES
#PBFORMS BEGIN CONSTANTS
%TEXTBOX1    = 1001
%IDM_CLEAR   = 2001
%IDM_DISPLAY = 2002
%TEXTBOX2    = 2003
%IDM_SEND    = 2004
#PBFORMS END CONSTANTS
#PBFORMS DECLARATIONS
'------------------------------------------------------------------------------
THREAD FUNCTION ConnectionMain(BYVAL tcpfilenumber AS LONG) AS LONG

 LOCAL sPacket          AS STRING
 LOCAL sBuffer          AS STRING
 LOCAL BytesToReceive   AS DWORD
 LOCAL BytesLeft        AS DWORD
 LOCAL StartByte        AS DWORD

 tTcpFileNumber = tcpFileNumber 'so we send back to correct user

DO 'check first 6-bytes and sUser$
 sPacket = ""

 TCP RECV tcpFilenumber,6,sBuffer
 IF ERR OR LEN(sBuffer) = 0 THEN EXIT DO
 IF LEN(sBuffer) < 6 THEN logit USING$("[# byte_, needed 6]",LEN(sBuffer)):BEEP:SLEEP %TCP_TIMEOUT:EXIT DO '(wait,browsers retry) close, finish thread
 IF MID$(sBuffer,5) <> $ValidUser THEN
    BEEP:logit "invalid user, SLEEP" + STR$(%TCP_TIMEOUT)
    SLEEP %TCP_TIMEOUT
    BEEP:logit "tired of waiting, so finishing thread"
    EXIT DO 'then TCP CLOSE, exit thread
 END IF

 BytesToReceive  = CVDWD(sBuffer)  'don't process strings over 100 (500MB about max in 32-bit)
 IF bytesToReceive > 200000000 THEN logit USING$("#, over 200 million bytes",BytesToReceive):EXIT DO

 BytesLeft = BytesToReceive
 IF ERR OR BytesLeft = 0 THEN EXIT DO 'nothing left to do
 sPacket = SPACE$(BytesToReceive)     'allocate space once
 StartByte = 1

 DO
  TCP RECV tcpfilenumber,BytesLeft, sBuffer
  IF ERR OR LEN(sBuffer) = 0 THEN EXIT DO

  MID$(sPacket,StartByte) = sBuffer
  StartByte = StartByte + LEN(sBuffer)
  BytesLeft = BytesLeft-LEN(sBuffer)

  IF BytesLeft = 0  THEN
   Logit sPacket
   REM TCP SEND TcpFileNumber, MKDWD$(LEN(sPacket)) + $ValidUser + sPacket 'ECHO BACK
   EXIT DO
  END IF
 LOOP 'wait for more data
LOOP  'done waiting for data
 SELECT CASE AS LONG ERR
  CASE  0
  CASE 24  :Logit USING$("time-out thread #",tcpfilenumber)
  CASE 57  :logit USING$("dropped connection #",tcpfilenumber,tcpfilenumber)
  CASE ELSE:logit USING$("untrapped error # in thread #",ERR,tcpfilenumber)
 END SELECT

 TCP CLOSE tcpfilenumber
END FUNCTION
'-----------------------------------------------------------------------------------
FUNCTION PBMAIN()
  LOCAL hParent AS DWORD
  LOCAL lRslt AS LONG
#PBFORMS BEGIN DIALOG %IDD_DIALOG1->%IDR_MENU1->
  LOCAL hDlg   AS DWORD
  LOCAL hFont1 AS DWORD
  LOCAL hFont2 AS DWORD

  DIALOG NEW hParent, "", 360, 153, 662, 347, %WS_POPUP OR %WS_BORDER OR _
    %WS_DLGFRAME OR %WS_THICKFRAME OR %WS_CAPTION OR %WS_SYSMENU OR _
    %WS_MINIMIZEBOX OR %WS_CLIPSIBLINGS OR %WS_VISIBLE OR %DS_MODALFRAME OR _
    %DS_3DLOOK OR %DS_NOFAILCREATE OR %DS_SETFONT, %WS_EX_CONTROLPARENT OR _
    %WS_EX_LEFT OR %WS_EX_LTRREADING OR %WS_EX_RIGHTSCROLLBAR, TO hDlg
  CONTROL ADD TEXTBOX, hDlg, %TEXTBOX1, "", 5, 10, 650, 155, %WS_CHILD OR _
    %WS_VISIBLE OR %WS_HSCROLL OR %WS_VSCROLL OR %ES_LEFT OR %ES_MULTILINE _
    OR %ES_AUTOHSCROLL OR %ES_AUTOVSCROLL, %WS_EX_CLIENTEDGE OR %WS_EX_LEFT _
    OR %WS_EX_LTRREADING OR %WS_EX_RIGHTSCROLLBAR
  CONTROL ADD TEXTBOX, hDlg, %TEXTBOX2, "PowerBASIC Rocks!", 5, 175, 590, 75, %WS_CHILD OR _
    %WS_VISIBLE OR %WS_TABSTOP OR %WS_HSCROLL OR %WS_VSCROLL OR %ES_LEFT OR _
    %ES_MULTILINE OR %ES_AUTOHSCROLL OR %ES_AUTOVSCROLL OR %ES_WANTRETURN, _
    %WS_EX_CLIENTEDGE OR %WS_EX_LEFT OR %WS_EX_LTRREADING OR _
    %WS_EX_RIGHTSCROLLBAR

  FONT NEW "Courier New", 8, 0, %ANSI_CHARSET TO hFont1
  FONT NEW "MS Sans Serif", 12, 0, %ANSI_CHARSET TO hFont2

  CONTROL SET FONT hDlg, %TEXTBOX1, hFont1
  CONTROL SET FONT hDlg, %TEXTBOX2, hFont2

  AttachMENU1 hDlg
#PBFORMS END DIALOG
  ghDlg = hDlg
  StartListener
  DIALOG SHOW MODAL hDlg CALL MyCallBack
  FUNCTION = lRslt
END FUNCTION
'------------------------------------------------------------------------------
SUB LogIt(s AS STRING) THREADSAFE
 gsAll+=s + $CRLF
 CONTROL SET TEXT ghDlg, %TEXTBOX1,gsAll
 CONTROL SEND ghDlg,%TEXTBOX1,%WM_VSCROLL,%SB_BOTTOM,0  'takes time!
END SUB
'------------------------------------------------------------------------------
FUNCTION AttachMENU1(BYVAL hDlg AS DWORD) AS DWORD
#PBFORMS BEGIN MENU %IDR_MENU1->%IDD_DIALOG1
  LOCAL hMenu   AS DWORD

  MENU NEW BAR TO hMenu
  MENU ADD STRING, hMenu, "Clear", %IDM_CLEAR, %MF_ENABLED
  MENU ADD STRING, hMenu, "Display", %IDM_DISPLAY, %MF_ENABLED
  MENU ADD STRING, hMenu, "Send", %IDM_SEND, %MF_ENABLED

  MENU ATTACH hMenu, hDlg
#PBFORMS END MENU
  FUNCTION = hMenu
END FUNCTION
'------------------------------------------------------------------------------
SUB StartListener
 LOCAL lhIPAddress    AS DWORD   'listen ip as dword
 LOCAL nListenSocket  AS DWORD   'listen socket

 HOST ADDR $Host TO lhIPAddress  'Convert to IP addr
 IF ISFALSE lhIPAddress THEN LogIt "Invalid IP Address " + $Host

 TCP OPEN SERVER ADDR lhIPAddress PORT %Port AS %ListenFileNumber TIMEOUT %TCP_TIMEOUT
 IF ERR THEN
    ? "Unable to open port " + STR$(%Port) + " on host " & $Host,%MB_SYSTEMMODAL,ERROR$ + STR$(ERR)
    EXIT SUB
 END IF
 TCP NOTIFY %ListenFileNumber, ACCEPT TO ghDlg AS %Tcp_Notify        'notify of connections
 DIALOG SET TEXT ghDlg,USING$("host &     port #     TimeOut # ms",$Host,%Port,%TCP_TIMEOUT)
END SUB

'------------------------------------------------------------------------------
CALLBACK FUNCTION MyCallBack
  LOCAL NewTcpFileNumber,h AS LONG

 SELECT CASE AS LONG CB.MSG

  CASE %TCP_NOTIFY
   IF LO(WORD, CB.LPARAM) = %FD_ACCEPT THEN
    NewTcpFileNumber = FREEFILE
    TCP ACCEPT %ListenFileNumber AS NewTcpFileNumber
    THREAD CREATE ConnectionMain(NewTcpFileNumber) TO h
    THREAD CLOSE h TO h
    SLEEP 5
   END IF

   CASE %WM_INITDIALOG
     ghDlg = CB.HNDL

   CASE %WM_COMMAND
    SELECT CASE AS LONG CB.CTL

      CASE %IDM_CLEAR
       gsAll = ""
       CONTROL SET TEXT CB.HNDL,%TEXTBOX1,gsAll

      CASE %IDM_Display
       CONTROL SET TEXT ghDlg, %TEXTBOX1,USING$("Total bytes #",LEN(gsAll))
       CONTROL SEND ghDlg,%TEXTBOX1,%WM_VSCROLL,%SB_BOTTOM,0

      CASE %IDM_SEND
        LOCAL s AS STRING
        CONTROL GET TEXT ghDlg,%TEXTBOX2 TO s
        IF LEN(s) THEN
          CONTROL SET TEXT ghDlg,%TEXTBOX2,""
          ClientSend $ValidUser,$ClientIp,%port,s  'open new connection
          Logit "ME> " +s
        ELSE
          BEEP
        END IF
        CONTROL SET FOCUS ghDlg,%TEXTBOX2        '

    END SELECT

 END SELECT
END FUNCTION
'-----------------------------------------------------------------------------------
FUNCTION ClientSend(sUser AS STRING,sHost AS STRING,portnumber AS LONG,sSendThis AS STRING) AS LONG
  LOCAL TcpFileNumber AS LONG
  LOCAL sBuffer          AS STRING
  LOCAL BytesToReceive   AS DWORD
  LOCAL BytesLeft        AS DWORD
  LOCAL BytesReceived    AS DWORD
  LOCAL StartByte        AS DWORD
  TcpFileNumber = FREEFILE   'send data:4-bytes dword length of sSend$ + sUser$ + sSend$
  TCP OPEN PORT PortNumber AT shost AS #TcpFileNumber
  IF ERR THEN FUNCTION = ERR:EXIT FUNCTION
  TCP SEND TcpFileNumber, MKDWD$(LEN(sSendThis)) + suser + sSendThis
  IF ERR THEN FUNCTION = ERR:TCP CLOSE #TcpFileNumber:EXIT FUNCTION
  TCP CLOSE tcpfilenumber
END FUNCTION

[Knuth Konrad]

You need to have a look at Slack. It's free for smaller teams (like yours) and is absolutely fantastic for developers/devops-kinda organizations. It ties into so many useful dev-related services (e.g. Github, see the workflow description).

If you don't want to trust a cloud service, Mastodon is a self-hosted Slack clone.

And if you happen to have an Office 365 account, MS Teams is included, which is MS' Slack clone. And that MS felt the need to create a clone of an existing service, should give you an idea of the importance of Slack.

[George Bleck]

I wrote a simple one about 25 years ago but the code is corporate proprietary and at this stage quite old but here some things I had to think about...

• Is this Peer to peer communications only or is central server coordinated communications (central server may be required if you want more then 2 people chatting unless you do complex pass alongs between the peers)
• Is this local only or will it traverse the internet, if internet based you will need to be concerned about opening ports on routers and/or firewalls
• Also, if on the internet, you really MUST be concerned about security of the data... so strong, standards based, encryption is a must. Even if you "think" it won't need it, you should do it. You never know what people will type and who might be eavesdropping
• Will this be text only? Allow pictures, emoticon images, Plain text vs RTF, unicode, allow bold/italics/underlines, colors, etc

[George Bleck]

Some other thoughts...

You might want to look at different XMPP protocol clients that support visual impairment capabilities (e.g. https://github.com/rhcarvalho/xmppvox)

Alternately, if there is a web based one it might be fairly simple enough to change the CSS or embedded font descriptions to use larger or high contrast schemes.

[Michael Mattias]

I wrote a simple one about 25 years ago...

So did I ... but that did not use TCP or "clients" or anything like that... it was all written on top of PB "OPEN COM..."

That was two-way chat only, not a 'party line' but I'm not quite sure what Gary wants here... "chat" to me means, "exactly two parties at any one time."

[Shawn Anderson]

We use google hangouts at work but I've written an in-browser messager using PB on the back end. If you want a desktop solution then Mike's solution is probably the way to go.

[Jim Fritts]

All,

For those that were wondering here is Gary's requirement:

I remember such an app for a LAN, but in this case the co-worker is in a different city.

Very funny MCM. Good thing this Blog is not a telephone conversation. Humans have a problem sending and receiving (when performed at the same time) by any historical method. "Oh, let me see did he send 10 drum beats or 9 in the middle of my drum roll?"

[Mike Doty]

Jim,
Did someone post anything that didn't work over the internet?

Change the destination IP to your own remote IP and this can be tested over the internet on a single machine as long as port or app is allowed through firewall.
I added some resizing code and changed menu item Send to &Send so Alt+S will send.

#PBFORMS CREATED V2.01
$ValidUser = CHR$(0,1) 'username
$Host     = "192.168.0.2"  'my IP or computer name
$ClientIp = "192.168.0.2"  'send back to myself
%Port     = 51234
%TCP_TIMEOUT = 10000
%ListenFileNumber = 9999
%Tcp_Notify = %WM_USER + 4093
GLOBAL ghDlg AS DWORD, gsAll AS STRING 'only for testing
THREADED tTCPFileNumber AS LONG        'each connection
'-----------------------------------------------------------------------------------
#PBFORMS BEGIN INCLUDES
#INCLUDE ONCE "WIN32API.INC"
#PBFORMS END INCLUDES
#PBFORMS BEGIN CONSTANTS
%TEXTBOX1    = 1001
%IDM_CLEAR   = 2001
%IDM_DISPLAY = 2002
%TEXTBOX2    = 2003
%IDM_SEND    = 2004

#PBFORMS END CONSTANTS
#PBFORMS DECLARATIONS
'------------------------------------------------------------------------------
THREAD FUNCTION ConnectionMain(BYVAL tcpfilenumber AS LONG) AS LONG

 LOCAL sPacket          AS STRING
 LOCAL sBuffer          AS STRING
 LOCAL BytesToReceive   AS DWORD
 LOCAL BytesLeft        AS DWORD
 LOCAL StartByte        AS DWORD

 tTcpFileNumber = tcpFileNumber 'so we send back to correct user

DO 'check first 6-bytes and sUser$
 sPacket = ""

 TCP RECV tcpFilenumber,6,sBuffer
 IF ERR OR LEN(sBuffer) = 0 THEN EXIT DO
 IF LEN(sBuffer) < 6 THEN logit USING$("[# byte_, needed 6]",LEN(sBuffer)):BEEP:SLEEP %TCP_TIMEOUT:EXIT DO '(wait,browsers retry) close, finish thread
 IF MID$(sBuffer,5) <> $ValidUser THEN
    BEEP:logit "invalid user, SLEEP" + STR$(%TCP_TIMEOUT)
    SLEEP %TCP_TIMEOUT
    BEEP:logit "tired of waiting, so finishing thread"
    EXIT DO 'then TCP CLOSE, exit thread
 END IF

 BytesToReceive  = CVDWD(sBuffer)  'don't process strings over 100 (500MB about max in 32-bit)
 IF bytesToReceive > 200000000 THEN logit USING$("#, over 200 million bytes",BytesToReceive):EXIT DO

 BytesLeft = BytesToReceive
 IF ERR OR BytesLeft = 0 THEN EXIT DO 'nothing left to do
 sPacket = SPACE$(BytesToReceive)     'allocate space once
 StartByte = 1

 DO
  TCP RECV tcpfilenumber,BytesLeft, sBuffer
  IF ERR OR LEN(sBuffer) = 0 THEN EXIT DO

  MID$(sPacket,StartByte) = sBuffer
  StartByte = StartByte + LEN(sBuffer)
  BytesLeft = BytesLeft-LEN(sBuffer)

  IF BytesLeft = 0  THEN
   Logit sPacket
   REM TCP SEND TcpFileNumber, MKDWD$(LEN(sPacket)) + $ValidUser + sPacket 'ECHO BACK
   EXIT DO
  END IF
 LOOP 'wait for more data
LOOP  'done waiting for data
 SELECT CASE AS LONG ERR
  CASE  0
  CASE 24  :Logit USING$("time-out thread #",tcpfilenumber)
  CASE 57  :logit USING$("dropped connection #",tcpfilenumber,tcpfilenumber)
  CASE ELSE:logit USING$("untrapped error # in thread #",ERR,tcpfilenumber)
 END SELECT

 TCP CLOSE tcpfilenumber
END FUNCTION
'-----------------------------------------------------------------------------------
FUNCTION PBMAIN()
  LOCAL hParent AS DWORD
  LOCAL lRslt AS LONG
#PBFORMS BEGIN DIALOG %IDD_DIALOG1->%IDR_MENU1->
  LOCAL hDlg   AS DWORD
  LOCAL hFont1 AS DWORD

  DIALOG NEW PIXELS,hParent, "", 0 ,0, 600, 600, %WS_POPUP OR %WS_BORDER OR _
    %WS_DLGFRAME OR %WS_THICKFRAME OR %WS_CAPTION OR %WS_SYSMENU OR _
    %WS_MINIMIZEBOX OR %WS_CLIPCHILDREN OR %WS_VISIBLE OR %DS_MODALFRAME OR _
    %DS_3DLOOK OR %DS_NOFAILCREATE OR %DS_SETFONT, %WS_EX_CONTROLPARENT OR _
    %WS_EX_LEFT OR %WS_EX_LTRREADING OR %WS_EX_RIGHTSCROLLBAR, TO hDlg
  CONTROL ADD TEXTBOX, hDlg, %TEXTBOX1, "", 0, 0, 500, 100, %WS_CHILD OR _
    %WS_VISIBLE OR %WS_HSCROLL OR %WS_VSCROLL OR %ES_LEFT OR %ES_MULTILINE _
    OR %ES_AUTOHSCROLL OR %ES_AUTOVSCROLL, %WS_EX_CLIENTEDGE OR %WS_EX_LEFT _
    OR %WS_EX_LTRREADING OR %WS_EX_RIGHTSCROLLBAR
  CONTROL ADD TEXTBOX, hDlg, %TEXTBOX2, "PowerBASIC Rocks!", 0, 100, 500, _
    100, %WS_CHILD OR %WS_VISIBLE OR %WS_TABSTOP OR %WS_HSCROLL OR _
    %WS_VSCROLL OR %ES_LEFT OR %ES_MULTILINE OR %ES_AUTOHSCROLL OR _
    %ES_AUTOVSCROLL OR %ES_WANTRETURN, %WS_EX_CLIENTEDGE OR %WS_EX_LEFT OR _
    %WS_EX_LTRREADING OR %WS_EX_RIGHTSCROLLBAR

  FONT NEW "Courier New", 8, 0, %ANSI_CHARSET TO hFont1

  CONTROL SET FONT hDlg, %TEXTBOX1, hFont1
  CONTROL SET FONT hDlg, %TEXTBOX2, hFont1

  AttachMENU1 hDlg
#PBFORMS END DIALOG
  ghDlg = hDlg
  StartListener
  DIALOG SHOW MODAL hDlg CALL MyCallBack
  FUNCTION = lRslt
END FUNCTION
'------------------------------------------------------------------------------
SUB LogIt(s AS STRING) THREADSAFE
 gsAll+=s + $CRLF
 CONTROL SET TEXT ghDlg, %TEXTBOX1,gsAll
 CONTROL SEND ghDlg,%TEXTBOX1,%WM_VSCROLL,%SB_BOTTOM,0  'takes time!
END SUB
'------------------------------------------------------------------------------
FUNCTION AttachMENU1(BYVAL hDlg AS DWORD) AS DWORD
#PBFORMS BEGIN MENU %IDR_MENU1->%IDD_DIALOG1
  LOCAL hMenu   AS DWORD

  MENU NEW BAR TO hMenu
  MENU ADD STRING, hMenu, "Clear", %IDM_CLEAR, %MF_ENABLED
  MENU ADD STRING, hMenu, "Display", %IDM_DISPLAY, %MF_ENABLED
  MENU ADD STRING, hMenu, "&Send", %IDM_SEND, %MF_ENABLED

  MENU ATTACH hMenu, hDlg
#PBFORMS END MENU
  FUNCTION = hMenu
END FUNCTION
'------------------------------------------------------------------------------
SUB StartListener
 LOCAL lhIPAddress    AS DWORD   'listen ip as dword
 LOCAL nListenSocket  AS DWORD   'listen socket

 HOST ADDR $Host TO lhIPAddress  'Convert to IP addr
 IF ISFALSE lhIPAddress THEN LogIt "Invalid IP Address " + $Host

 TCP OPEN SERVER ADDR lhIPAddress PORT %Port AS %ListenFileNumber TIMEOUT %TCP_TIMEOUT
 IF ERR THEN
    ? "Unable to open port " + STR$(%Port) + " on host " & $Host,%MB_SYSTEMMODAL,ERROR$ + STR$(ERR)
    EXIT SUB
 END IF
 TCP NOTIFY %ListenFileNumber, ACCEPT TO ghDlg AS %Tcp_Notify        'notify of connections
 DIALOG SET TEXT ghDlg,USING$("host &     port #     TimeOut # ms",$Host,%Port,%TCP_TIMEOUT)
END SUB

'------------------------------------------------------------------------------
CALLBACK FUNCTION MyCallBack
  LOCAL NewTcpFileNumber,h AS LONG

 SELECT CASE AS LONG CB.MSG

  CASE %TCP_NOTIFY
   IF LO(WORD, CB.LPARAM) = %FD_ACCEPT THEN
    NewTcpFileNumber = FREEFILE
    TCP ACCEPT %ListenFileNumber AS NewTcpFileNumber
    THREAD CREATE ConnectionMain(NewTcpFileNumber) TO h
    THREAD CLOSE h TO h
    SLEEP 5
   END IF

   CASE %WM_INITDIALOG
     ghDlg = CB.HNDL
     ExpandAndCenterDialog 'expands or contracts size
   CASE %WM_SIZE
      resize

   CASE %WM_COMMAND
    SELECT CASE AS LONG CB.CTL
      CASE %IDM_CLEAR
       gsAll = ""
       CONTROL SET TEXT CB.HNDL,%TEXTBOX1,gsAll

      CASE %IDM_Display
       CONTROL SET TEXT ghDlg, %TEXTBOX1,USING$("Total bytes #",LEN(gsAll))
       CONTROL SEND ghDlg,%TEXTBOX1,%WM_VSCROLL,%SB_BOTTOM,0

      CASE %IDM_SEND
        LOCAL s AS STRING
        CONTROL GET TEXT ghDlg,%TEXTBOX2 TO s
        IF LEN(s) = 0 THEN s = "Sent nothing at " + TIME$
        IF LEN(s) THEN
          CONTROL SET TEXT ghDlg,%TEXTBOX2,""
          ClientSend $ValidUser,$ClientIp,%port,s  'open new connection
          'Logit "ME> " +s
        ELSE
          BEEP
        END IF
        CONTROL SET FOCUS ghDlg,%TEXTBOX2        '

    END SELECT

 END SELECT
END FUNCTION
'-----------------------------------------------------------------------------------
FUNCTION ClientSend(sUser AS STRING,sHost AS STRING,portnumber AS LONG,sSendThis AS STRING) AS LONG
  LOCAL TcpFileNumber AS LONG
  LOCAL sBuffer          AS STRING
  LOCAL BytesToReceive   AS DWORD
  LOCAL BytesLeft        AS DWORD
  LOCAL BytesReceived    AS DWORD
  LOCAL StartByte        AS DWORD
  TcpFileNumber = FREEFILE   'send data:4-bytes dword length of sSend$ + sUser$ + sSend$
  TCP OPEN PORT PortNumber AT shost AS #TcpFileNumber
  IF ERR THEN FUNCTION = ERR:EXIT FUNCTION
  TCP SEND TcpFileNumber, MKDWD$(LEN(sSendThis)) + suser + sSendThis
  IF ERR THEN FUNCTION = ERR:TCP CLOSE #TcpFileNumber:EXIT FUNCTION
  TCP CLOSE tcpfilenumber
END FUNCTION

SUB ExpandAndCenterDialog
  LOCAL ScreenWidth,ScreenHeight,DialogWidth,DialogHeight,DialogLeft,DialogTop AS LONG
  DIALOG GET SIZE ghdlg TO DialogWidth,DialogHeight
  DESKTOP GET SIZE TO ScreenWidth,ScreenHeight
  DIALOG SET SIZE ghDlg, ScreenWidth\2,ScreenHeight\2
  DIALOG SET LOC  ghDlg, (ScreenWidth\2)-(DialogWidth\2),(ScreenHeight\2)-(DialogHeight\2)
END SUB

SUB Resize
  LOCAL TheWidth,TheHeight AS LONG
  DIALOG GET SIZE ghDlg TO TheWidth,TheHeight
  TheHeight=TheHeight-68 'using pixels in dialog
  CONTROL SET SIZE   ghDlg, %TEXTBOX1, TheWidth-20,TheHeight*.8
  CONTROL SET SIZE   ghDlg, %TEXTBOX2, TheWidth-20,TheHeight*.2
  CONTROL SET LOC    ghDlg, %TEXTBOX2, 0,TheHeight*.8
END SUB

[Jim Fritts]

Mike,
Looks like just standard LAN to me. I'm thinking MQTT would be the way to go for this. Hopefully Jerry Wilson will chime in here. He was working in that direction for IoT sensors. Obviously IPV6 should make this sort of communication very easy. Anyone willing to share?