SharpPad

A LINQPad-style C# scratchpad for Linux. Avalonia desktop app: write C# in the editor, hit F5, get LINQPad-style rich Dump() output.

Install

One-liner (detects your distro and CPU, then installs the matching package):

curl -fsSL https://raw.githubusercontent.com/stevedowling/SharpPad/main/install.sh | bash

The installer picks a .deb on Debian/Ubuntu, an .rpm on Fedora/RHEL/openSUSE, and a portable .tar.gz on Arch and everything else. Overrides: SHARPPAD_VERSION=1.2.0 for a specific release, SHARPPAD_METHOD=tarball to force a method. Remove with install.sh --uninstall.

Prebuilt packages for each release (x64 and arm64) are on the Releases page. The app bundle is self-contained, but compiling scripts still needs the .NET 10 SDK installed (dotnet-sdk-10.0); the installer warns if it's missing.

Requirements

.NET 10 SDK on the machine (the SDK, not just the runtime — scripts are compiled with dotnet build).

Run from source

dotnet run --project src/SharpPad.App

Building release packages

packaging/build-linux-packages.sh <rid> <version> produces a .deb, .rpm, and .tar.gz for one runtime (linux-x64 or linux-arm64) into dist/. Needs the .NET 10 SDK, plus fpm and rpm/rpmbuild for the deb/rpm targets. The release GitHub Actions workflow runs this for both architectures and publishes the artifacts to a GitHub Release when you push a v*.*.* tag.

Usage

Scripts are top-level statements; classes/records can follow below. Dump() works on anything and returns its input for chaining.

#r "nuget: Newtonsoft.Json, 13.0.3"    // NuGet reference (version optional -> latest)
#r "/path/to/Your.dll"                 // local DLL reference
#connection "mydb"                     // named DB connection (Manage… in toolbar)

Enumerable.Range(1, 20).Where(n => n % 3 == 0).Dump("multiples of 3");
Query("select * from people where age > @a", new { a = 30 }).Dump();

With a connection active (directive or toolbar dropdown): Connection (open IDbConnection), Query(sql, param), Query<T>(sql, param), QuerySingle<T>, Execute — all Dapper-backed. Providers: sqlite, postgres, sqlserver, mysql.

Keys: F5 run, Ctrl+S save. Saved scripts live in ~/.sharppad/scripts and appear in the sidebar. Connections are stored in ~/.sharppad/connections.json (plain text — treat accordingly).

How it works

Each run generates a real net10.0 console project under ~/.sharppad/build/<hash>/ (user code goes into Program.cs with directive lines blanked, so compiler line numbers match the editor), builds it with dotnet build — MSBuild/NuGet do all reference resolution — and runs it as a child process. Output streams back as JSON frames on stdout (Dump() trees, redirected console, exceptions); Stop kills the process tree. First run of a script restores packages (a few seconds); subsequent runs are incremental (~1–2 s).

SHARPPAD_HOME overrides ~/.sharppad; SHARPPAD_DOTNET overrides the dotnet binary used for script builds.

Tests

dotnet test          # engine end-to-end (real builds/processes) + headless UI smoke tests

Known limitations / v2 seams

• No IntelliSense — syntax highlighting only (TextMate). Seam: RoslynPad's editor packages, or a Roslyn completion service over the generated project.
• No typed LINQ-to-database (LINQPad's headline feature). SQL + Dapper + LINQ over results instead. Seam: EF Core dotnet ef dbcontext scaffold into the generated project — the project-per-script model was chosen partly to make this drop in cleanly.
• Dump() output is fully materialized up to limits (depth 5, 1000 items, then truncation markers) rather than lazily expandable across the process boundary.
• Scripts run to completion; no Util.Cache, no charting, no Dump() refresh.
• Console input (Console.ReadLine) is not wired up.
• Avalonia pinned to 11.3.x (12.x was released after this was written and hasn't been evaluated).
• Known security advisory (pre-existing, not introduced by the .NET 10 migration): Microsoft.Data.Sqlite transitively bundles SQLitePCLRaw.lib.e_sqlite3, which ships SQLite 3.49.1 — vulnerable to CVE-2025-6965 (memory corruption from a crafted aggregate query, fixed in SQLite 3.50.2). As of this writing even the latest Microsoft.Data.Sqlite (10.0.10) still bundles 3.49.1, so there is no clean version-bump fix yet; dotnet build will emit NU1903. Practical risk for a local scratchpad where you run your own SQL against your own databases is low. Revisit when a SQLitePCLRaw release bundling SQLite 3.50.2+ ships.