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Introducing Sploosh!

🐚 Introducing Sploosh! – A C# Shell Project

Ever thought to yourself, “You know what my Linux box needs? A shell written in C#”?

Me neither — until I did.

Welcome to Sploosh!, my somewhat serious, occasionally snarky journey into building a POSIX-compliant shell using C# on Linux. This blog series will chronicle the development of this project: from hacky beginnings to a (hopefully) usable command-line environment.

Why Build a Shell in C#?

I’ve spent most of my professional life knee-deep in .NET — writing enterprise apps, consuming APIs, swearing at WCF, and generally getting stuff done in C#. But every so often, I like to step outside the usual day-job code and work on something… weirder.

Enter: Sploosh!

This started as a side project for fun, but quickly turned into a great exercise in systems thinking, interprocess communication, and how far you can push C# in a traditionally UNIX-y domain.

Plus, writing a shell forces you to think deeply about:

  • Process management
  • Redirection (>, >>, <, 2>, etc.)
  • Command parsing
  • Signals
  • Built-in vs external commands
  • POSIX behavior expectations

And that’s just the first leg of the journey.

What’s Done So Far

Right now, Sploosh! can:

  • Start a REPL that parses and executes basic commands
  • Handle built-in commands like cd and exit
  • Execute external programs with arguments
  • Perform rudimentary input/output redirection (>, >>, <, 2>)
  • Launch from the CLI using dotnet run (still working on standalone execution issues)

Most recently, I’ve been tackling redirection, making sure it works even with built-in commands — not just spawned processes. I’m also starting to design a Command abstraction to cleanly model the steps from token parsing to execution.

There’s a lot more on the roadmap — piping, job control, background processes, command substitution, maybe even tab completion someday. But for now, it’s one test case at a time.

What’s Next?

Coming up:

  • A formal Command class to unify command parsing and execution
  • More robust error handling
  • Test suite integration that actually works outside of the CodeCrafters platform
  • Eventually, building something worthy of daily driver status (or at least not crashing every 5 minutes)

This is as much a passion project as it is a learning tool. I’ll be using this blog to share code snippets, design thoughts, gotchas, and a few rants along the way.

So if you’ve ever wanted to see someone try to build a POSIX shell in a non-traditional language… buckle up.

Sploosh! is just getting started.