A UI-powered grep-like search tool for Windows. Built on .NET 10 and WinUI 3.
Current version: 1.0
- Fast. Memory-mapped I/O, SIMD-vectorized byte search over UTF-8, per-file parallelism, and ripgrep-style required-literal extraction for regex queries. On real corpora, comparable to
rg. - Any file size. Files above 2 GiB stream through a chunked search path (newline-aligned 64 MiB windows); files above 4 MiB stream through replace via a sibling temp + atomic rename. No silent skipping for big files.
- Three-section form: Where / What / Filter. Each section snapshots into a preset (with hotkey support); presets compose so you can mix a saved root with a saved filter.
- Live filter on results. Narrow the result set without re-running the search; every export, copy, and replace respects the current filter.
- Atomic, encoding-safe replace. BOM-detected encoding round-trips through the rewrite; CRLF/LF line endings are preserved per-line; replace runs in parallel across cores; Cancel and Undo are first-class.
- Right-click results menu — Open in editor / Open with… / Open containing folder / Cut / Copy / Copy paths / Copy filenames / Copy lines / Copy as CSV / Delete (Recycle Bin) / Properties.
- Excel + CSV export. Real
.xlsxvia ClosedXML, RFC-4180 CSV. - Inverse search and search-in-currently-found-files for two-pass refinement.
- DOCS.md — full user manual (every feature, every quirk).
- DEVELOPMENT.md — architecture, testing strategy, performance levers, build instructions, project layout.
- Run
LionGrep.exe. - Drop one or more directories into Search in.
- Type a pattern in Search for.
- Press Ctrl+Enter.
- Double-click any result to open it in your editor (configure under the gear icon).
Press Ctrl+Alt+Enter to rewrite matches on disk.
# Build everything (Windows + .NET 10 SDK + WinAppSDK 2.0 required).
dotnet build LionGrep.slnx -c Debug -p:Platform=x64
# Run.
dotnet run --project LionGrep/LionGrep.csproj -c Debug -p:Platform=x64
# Fast unit tests (~200, NUnit, no UI).
dotnet test LionGrep.Core.Tests/LionGrep.Core.Tests.csproj
# Slow end-to-end UI smoke (FlaUI; build the app first).
dotnet test LionGrep.UI.Tests/LionGrep.UI.Tests.csproj -s LionGrep.UI.Tests/LionGrep.UI.Tests.runsettingsSee DEVELOPMENT.md for everything else.
- Windows 10 1809 (build 17763) or newer.
- For development: .NET 10 SDK and the Windows App SDK workload.
Licensed under the GNU Affero General Public License v3.0 — see LICENSE.md.