nuxmux

Small shim multiplexer for tools. At build time it generates shims and a nuxmux.config file next to each shim directory. At runtime each shim resolves the real tool by its own filename and delegates execution to the first match in the configured roots.

Quick start after NuGet import

1. Add the package.

<ItemGroup>
  <PackageReference Include="nuxmux" Version="x.y.z" PrivateAssets="all" />
</ItemGroup>

2. Provide tool globs (recursive supported) and a Path for shims (absolute, or relative to NuxmuxBaseDir).

<PropertyGroup>
  <NuxmuxBaseDir>$(MSBuildProjectDirectory)</NuxmuxBaseDir>
</PropertyGroup>
<ItemGroup>
  <NuxmuxDir Include="C:\tools1\*.exe" Path="mux\tools1" />
  <NuxmuxDir Include="C:\tools2\**\*.exe" Path="mux\tools2" />
  <NuxmuxDir Include="D:\llvm-pack\*.exe" Path="D:\mux\tools3" />
</ItemGroup>

3. Build.

dotnet build

4. Add the desired shim directories to PATH and call tools by name.

Each shim reads nuxmux.config located in the same directory. The config lists absolute root directories where the real binaries live. No binaries are copied; only shims are generated.

Parameters

• NuxmuxDir (Item): glob patterns of tool binaries. Order matters for resolution.
• Path (metadata): directory where shims and nuxmux.config for this item are generated. Relative paths are resolved against NuxmuxBaseDir.
• NuxmuxBaseDir (Property): base directory for relative Path values. Defaults to the project obj path.

What gets generated

• Shims are created in each Path (missing added, existing not overwritten).
• nuxmux.config is written next to the shims for each Path and rewritten whenever the target runs.
• Tool binaries are not copied.
• Extra files are never touched; extra shims are removed only when they match the current template.

MSBuild target

The package adds a buildTransitive target NuxmuxGenerate. It runs before CollectPackageReferences when @(NuxmuxDir) is non-empty and depends on Restore. The target generates shims/configs and syncs template-based shims.

Argument rewrite

Set NUXMUX_ARGS_REWRITE to rewrite arguments before the target tool is launched. Rules are applied to a merged argument string (with quotes added by nuxmux) and the result is split back into argv, in order.

Syntax (sed-like):

s<delim>pattern<delim>replacement<delim>[gims]

To scope a rule to a specific tool, prefix it with the tool name (without .exe), then a space:

tool s<delim>pattern<delim>replacement<delim>[gims]

Multiple rules can be separated by whitespace or ;. Use quotes to group rules that contain spaces.

The merged argument string is space-separated and padded with leading/trailing spaces. If you want to match whole arguments, prefer patterns like (^|\\s)--old(\\s|$) instead of ^/$ alone.

Examples:

NUXMUX_ARGS_REWRITE='s|^--bad$|--version|'
NUXMUX_ARGS_REWRITE='uname s#^-s$#-r#; git s#^--noop$#--version#'
NUXMUX_ARGS_REWRITE="s#^--old\\$#--new#;${NUXMUX_ARGS_REWRITE}"

In POSIX shells, use single quotes (or escape $ as \$) so $# in regex anchors is not expanded.

Notes

• Roots in nuxmux.config are absolute directories that contain the real binaries.
• Path can be absolute or relative to NuxmuxBaseDir.
• Shims are flat inside each Path (no subfolder mirroring).
• If multiple roots contain the same tool name, the first root in nuxmux.config wins.