MessageBox()/MessageBeep() Windows API Command-Line Utility

A complete, robust command-line utility to construct highly customized calls to the MessageBox() and MessageBeep() Windows APIs. Released under a MIT or LGPL license.

This project is intended primarily for use from batch files (.bat) and other scripts to display a modal message dialog. If it can be done with MessageBox(), it can be done with this command-line program.

Why would you need this? To easily display native Windows message boxes from command-line scripts that also returns the user's response (i.e. which button was pressed). Useful for handling critical application/script failures.

Features

• Command-line action!
• Verbose mode tells you exactly how MessageBox() or MessageBeep() will be called. No more guessing!
• Pre-built binaries using Visual Studio (statically linked C++ runtime, minimal file size of ~85K, direct Win32 API calls).
• Windows subsystem variant.
• Unicode support.
• Offers almost everything MessageBox() and MessageBeep() offers.
• Has a liberal open source license. MIT or LGPL, your choice.
• Sits on GitHub for all of that pull request and issue tracker goodness to easily submit changes and ideas respectively.

Useful Information

Running the command with the /? option will display the options:

(C) 2021 CubicleSoft.  All Rights Reserved.

Syntax:  messagebox.exe [options] [Text [Caption/Title]]

Options:
        /v
        Verbose mode.

        /p
        Parse Text for special escape sequences.
        Only '\n' and '\\' are supported.

        /f=Buttons
        Sets the buttons of the message box.
        The 'Buttons' can be one of:
        MB_ABORTRETRYIGNORE
        MB_CANCELTRYCONTINUE
        MB_OK (Default)
        MB_OKCANCEL
        MB_RETRYCANCEL
        MB_YESNO
        MB_YESNOCANCEL

        /f=Icon
        Sets the icon of the message box.
        The 'Icon' can be one of:
        MB_ICONERROR
        MB_ICONWARNING
        MB_ICONINFORMATION
        MB_ICONQUESTION

        /f=DefaultButton
        Sets the default button for the message box.
        The 'DefaultButton' can be one of:
        MB_DEFBUTTON1 (Default)
        MB_DEFBUTTON2
        MB_DEFBUTTON3
        MB_DEFBUTTON4

        /f=Modality
        Sets the modality for the message box.
        The 'Modality' can be one of:
        MB_APPLMODAL (Default)
        MB_SYSTEMMODAL
        MB_TASKMODAL

        /f=MiscFlag
        Sets the miscellaneous flags for the message box.
        Multiple /f options can be specified.
        Each 'MiscFlag' can be one of:
        MB_SIMPLEBEEP (Only when Title is not used)
        MB_HELP (Probably won't work)
        MB_DEFAULT_DESKTOP_ONLY
        MB_RIGHT
        MB_RTLREADING
        MB_SETFOREGROUND
        MB_TOPMOST
        MB_SERVICE_NOTIFICATION

        /w=Milliseconds
        The amount of time, in milliseconds, to wait.
        The default behavior is to wait indefinitely.
        This feature relies on an undocumented Windows API.

Example with verbose output:

C:\>messagebox.exe /v /f=MB_OKCANCEL /f=MB_ICONWARNING "The application crashed.  See the log file for details.  Press OK to continue or Cancel to exit now." "Oh Dear!"
Arguments:
        argv[0] = messagebox.exe
        argv[1] = /v
        argv[2] = /f=MB_OKCANCEL
        argv[3] = /f=MB_ICONWARNING
        argv[4] = The application crashed.  See the log file for details.  Press OK to continue or Cancel to exit now.
        argv[5] = Oh Dear!

MessageBox(
        hWnd = 0x008F0D4A,
        lpText = The application crashed.  See the log file for details.  Press OK to continue or Cancel to exit now.,
        lpCaption = Oh Dear!,
        uType = MB_OKCANCEL | MB_ICONWARNING | MB_DEFBUTTON1 | MB_APPLMODAL
);

Which waits for the message box to be closed and returns the return code of the selected button.

Windows Subsystem Variant

While messagebox.exe is intended for use with console apps, messagebox-win.exe is intended for detached console and GUI applications. Starting messagebox.exe in certain situations will briefly flash a console window before displaying the error message. Calling messagebox-win.exe instead will no longer show the console window.

Why not just use messagebox-win.exe? Since messagebox-win.exe starts as a Windows GUI application, there is the tendency for it to be run in the background and the message box that displays may not behave as a modal dialog. The software is a little bit trickier to work with as a result. It's also a few KB larger than messagebox.exe.

There is one additional option specifically for messagebox-win.exe called /attach which attempts to attach to the console of the parent process (if any).

Sources

The MessageBox() and MessageBeep() APIs on MSDN Library have the intimate details on each option:

• https://docs.microsoft.com/en-us/windows/desktop/api/winuser/nf-winuser-messagebox
• https://docs.microsoft.com/en-us/windows/desktop/api/winuser/nf-winuser-messagebeep