win-shim

Lightweight and customisable shim executable for Windows written in safe modern C++ 20.

Features

• Lightweight and Fast. Does not add to startup time, even for tiny utilities.
• Self-sufficient and clean. Does not read config files or write anywhere. Does not need or require any external runtimes.
• Mirrors original application icons, file information and version.
• Supports any command line, parametrised.
• Supports UI and command-line applications. UI applications are launched without console window, console apps get a console. Simple but tricky to implement.
• Respects original exit code.
• No hanging processes. Terminating shim terminates any process tree it has created.
• Fully UNICODE compliant.
• Secure
  • Disables dangerous UI capabilities:
    • Creating and switching desktops.
    • Changing display settings.
    • Logging of from Windows.
    • Changing system settings.
    • Optionally allows clipboard access.

How to Use

Download the latest release.

Originally this shim was written because I wanted to associate a file extension in Windows with vim, but opened as a tab in windows terminal instead of an ugly terminal popup window. WT does allow it, however I would need to build a command line like:

wt -w 0 nt vim.exe <path_to_file>

Unfortunately (until now, thanks to me!), you cannot associate a command line with an extension in Windows, only executable with an extension, so I though I'd build a shim executable for this.

In order to achieve this, run shmake like following:

.\shmake.exe -i vim.exe -o vw.exe -a "-w 0 nt vim.exe %s" --app-path wt.exe -c no-kill

which should generate a new executable winwt.exe that when called with an argument will open a tab in WT! %s is replaced by arguments passed to wimwt.exe when it executes. --app-path tell shim to launch wt.exe instead of input. -c tells that shim must not kill target process when it exists (wt launches, signals existing instance and exits).

Yes, the shim will have vim's icon and looks exactly like vim.exe in Windows explorer, even when you click "properties" on it.

Building

As this is Windows Exclusive, you need Visual Studio 2022+ with Windows SDK installed. Normally I would use CMake, but it is considerably harder (not impossible) when you need access to OS specific tools, especially native resources (which I utilise heavily to do the magic). It is also very well integrated with vcpkg.

shmake (but not shim) has dependency on:

• boost::program_options to present you with a nice command line.
• boost::algorithm to have access to some string manipulation algorithms.

All the dependencies are installed via vcpkg.
Also note that Debug builds used shared dependencies while Release builds use the static ones to produce a single portable shmake.exe.

vcpkg install boost-program-options:x64-windows boost-program-options:x64-windows-static boost-algorithm:x64-windows boost-algorithm:x64-windows-static

shim does not have any dependencies and is kept as small and light as possible.

Extra Oddness

shmake embeds shim inside it as a Windows native resource, so it's completely self-sufficient and can be distributed as a single .exe. To do that, shmake's pre-build step copies shim.exe to shim.bin before build (as a pre-build step). Apparently shim is set as a project dependency of shmake, so it generates a full usable binary.

Related Projects

• scoop-better-shim does a few things right, but is not complete.
• This stackoverflow answer has a good suggestion on changing exe subsystem.