BazzBasic Linux adaptation

[EkBass]

Editor note: This is analyzis from Mistral what needs to be done before BB runs with Linux.

BazzBasic Linux adaptation

Analysis of what must do before it is worth trying to build the
BazzBasic src for Linux.

Date: 2026-10-23, BazzBasic 1.6
Src: the interpreter only. The IDE is WinForms and stays Windows-only.

Summary

The core interpreter (lexer, interpreter, variables, file I/O, HTTP, JSON)
should run on Linux as it is. Six areas need changes first. Most of the
failures happen at runtime, not at compile time: a Win32 DllImport
compiles fine and throws DllNotFoundException only when it is called.

Must fix

1. Image loading uses System.Drawing

• src/Graphics/ShapeManager.cs line 89 (LOADIMAGE) and line 150 (LOADSHEET)
  use Bitmap, LockBits and Clone.
• Since .NET 7, System.Drawing.Common is Windows-only. On Linux these throw
  PlatformNotSupportedException.
• It is also the only reason the project targets net10.0-windows. Once it
  is replaced, the target can be plain net10.0.
• This is the biggest single job.

2. Native library names

SDL is reached through DllImport under these names:

File	Name used
src/SDL2/SDL2.cs line 35	"SDL2"
src/SDL2/SDL2_ttf.cs line 21	"SDL2_ttf"
src/Sound/SDL_mixer.cs line 26	"SDL2_mixer.dll"
src/Sound/SDL_mixer.cs line 129 onward	"SDL2.dll"

Linux distributions ship these as libSDL2-2.0.so.0,
libSDL2_mixer-2.0.so.0 and libSDL2_ttf-2.0.so.0. The plain
libSDL2.so link exists only when the -dev packages are installed.

Fix: one library-name mapping (NativeLibrary.SetDllImportResolver) added
at startup in Program.cs. The binding files do not need to change.

3. Audio driver forced to DirectSound

src/Program.cs line 32 sets SDL_AUDIODRIVER=directsound. DirectSound
does not exist on Linux, so sound would fail completely. Set it only on
Windows (OperatingSystem.IsWindows()).

4. Win32 calls that crash

Where	What happens on Linux
src/Graphics/Graphics.cs lines 149 and 185	Minimizing and restoring the console window (ShowWindow, GetConsoleWindow) is not inside a try. Every SCREEN and every shutdown from graphics mode would crash.
src/Interpreter/Interpreter.IO.cs lines 469-480	GETCONSOLE reads characters and colours back from the Windows console buffer (ReadConsoleOutputCharacter, ReadConsoleOutputAttribute). Linux terminals have no equivalent, so it would crash.
src/Program.cs line 128	GetConsoleProcessList is already inside try/catch, so it is harmless. It should still be guarded for clarity.

SetProcessDPIAware (src/Graphics/Graphics.cs line 26) is declared but
never called.

5. SHELL runs cmd.exe

src/File/FileManager.cs line 160 runs commands with cmd.exe /c. On Linux
it should be /bin/sh -c. BASIC programs that call Windows commands will not
port anyway; that belongs in the manual.

6. -exe packaging

• src/Program.cs line 313 always names the output .exe.
• The written file is not marked executable. File.SetUnixFileMode fixes
  that.
• Appending code to a Linux single-file executable should work the same way
  as on Windows, but this is unverified and needs a test.

Smaller items

• DRAWSTRING font: FindArialFont (src/Graphics/Graphics.cs line 1071)
  looks only next to the exe and in the Windows Fonts folder. Linux has no
  Arial by default, so DRAWSTRING will not work. Either add Linux font paths,
  or bundle a free Arial-compatible font such as Liberation Sans.
• Build files:
  • BazzBasic.csproj copies the Windows SDL DLLs into the output, so that
    copy needs a Windows-only condition.
  • build.bat is Windows-only. Linux needs a publish with -r linux-x64.
• Starting without arguments: the IDE is WinForms and will not run on
  Linux, so the no-arguments mode just prints the usage text. That text says
  BazzBasic.exe.

Not code, but behaviour to know

• Case-sensitive file names: INCLUDE "Lib.bas" will not find lib.bas
  on Linux. No backslash paths were found in the examples folder.
• Console keys: special keys (F-keys, numpad) are read differently in
  Linux terminals, so some INKEY codes may differ. This needs testing; it
  cannot be confirmed from the code.

Already fine

• Console colours, Clear, ReadKey, KeyAvailable and the cursor
  position.
• Path handling uses Path.Combine, and PRG_ROOT# uses the platform's own
  separator.
• Gamepad support goes through SDL.

Open decisions

1. Replacing System.Drawing.
   • StbImageSharp (recommended): pure C#, no native library, public
     domain. Should be trim-safe, but that must be checked with build.bat
     (no IL2xxx warnings).
   • SDL2_image: fits with the other SDL libraries, but adds one more
     native library on both platforms.
2. GETCONSOLE on Linux.
   • Return 0 and document it in the manual, or
   • have the interpreter keep its own copy of everything PRINT writes. This
     works but is much more work.

Unverified

• Whether a net10.0-windows project builds for a Linux target at all.
  It matters little, because decision 1 removes that target anyway.
• Whether -exe packaging works on Linux (item 6).
• Console INKEY key codes on Linux terminals.

Next step

Once the two decisions are made, write an implementation plan. It is a
multi-file change, so it goes through the phased workflow.