Icod.LineEditor

Icod.LineEditor is a managed .NET implementation of the classic Unix line-editing family: ed, its restricted form red, and the sed stream editor.

The repository targets .NET 10 and C# 13 and is designed for Windows, Linux, and macOS. The editors use managed code for their editing, regular-expression, record-processing, and command orchestration behavior rather than invoking the host system's ed, red, or sed executable.

This repository is the permanent home of the LineEditor family extracted from the former multi-suite Icod.CoreUtils development repository during Completion Gate G7.

SEO keywords and repository topics

The canonical discovery vocabulary for the NuGet package and GitHub repository is:

dotnet, csharp, line-editor, text-editor, stream-editor, ed, red, sed, gnu, unix, linux, windows, macos, cross-platform, command-line, cli, terminal, text-processing, regex, posix.

The same terms are emitted as PackageTags by Icod.LineEditor.Tools so package and repository discovery stay aligned.

Included commands

Command	Purpose
lineeditor	Distribution router that directly multiplexes the managed ed, red, and sed commands.
ed	Interactive and scriptable line-oriented text editor, following the GNU ed 1.22.5 compatibility profile.
red	Permanently restricted ed profile that disables shell execution and limits pathname syntax.
sed	Non-interactive stream editor with GNU-style addressing, substitutions, branching, hold space, in-place editing, sandboxing, and NUL-delimited records.

The router supports:

lineeditor ed [OPTION]...
lineeditor red [OPTION]...
lineeditor sed [OPTION]...

It calls the managed command implementations directly and does not spawn the standalone executables. The standalone ed, red, and sed programs remain first-class build and release outputs.

Installation and distribution

The distribution router is published as the .NET tool package Icod.LineEditor.Tools. Install version 1.1.1 with:

dotnet tool install --global Icod.LineEditor.Tools --version 1.1.1

The installed command is:

lineeditor

Use the router to select an editor:

lineeditor ed --help
lineeditor red --help
lineeditor sed --help

A missing or unknown router command is a usage error. lineeditor --help lists the supported commands and lineeditor --version reports the router version. Once a command is selected, arguments and standard streams are passed directly to the managed command implementation and its exit status is returned.

Tagged releases also provide framework-dependent ZIP archives for Windows, Linux, and macOS on x64 and ARM64. Each archive contains all four executable entry points:

lineeditor
ed
red
sed

Windows archive entries use the .exe suffix. Archives also contain the repository README.md and LICENSE and require the .NET 10 runtime.

This repository root README.md is also the NuGet package README for Icod.LineEditor.Tools. The router project packs this file at the package root as README.md, so the NuGet landing page and repository overview share the same installation, architecture, compatibility, and licensing documentation.

The narrower lineeditor/README.md documents the router itself; it is not the NuGet package README.

Icod.LineEditor.Ed.Shared

Icod.LineEditor.Ed.Shared is the repository-local mutable editor engine shared by ed and red.

It owns the Ed-family behavior that is genuinely shared by those two commands, including:

• mutable line storage and stable line identities;
• Ed address and range parsing;
• marks, cut/yank state, and reversible undo;
• append, insert, change, delete, move, copy, join, print, list, and number operations;
• searches and substitutions using the managed GNU BRE/ERE providers;
• global command execution;
• file reads, complete-file transactional writes, and append operations;
• shell/filter capability boundaries; and
• the immutable standard and restricted security profiles used by ed and red.

There is intentionally no general Icod.LineEditor.Shared project. The completed sharing audit found no cohesive common engine that should couple Sed's streaming execution model to Ed's mutable-buffer model.

Icod.LineEditor.Ed.Shared is a repository-local implementation library, not a separately published cross-suite dependency.

Architecture

The permanent dependency direction is:

Published neutral foundation
    Icod.CommandFramework 2.1.0
            ↓ PackageReference
    ┌──────────────────────────────┐
    │ Icod.LineEditor.Ed.Shared    │
    └──────────────────────────────┘
          ↓ ProjectReference
       ed             red

    Icod.CommandFramework 2.1.0
            ↓ PackageReference
           sed

        ed    red    sed
          \    |    /
           lineeditor
       distribution router

ed and red deliberately share the Ed engine through repository-local ProjectReference relationships. sed remains a separate execution engine. The lineeditor router references all three command projects only to provide in-process dispatch. No production project in this repository references Icod.CoreUtils.Shared.

Compatibility philosophy

The implementation aims for practical GNU-compatible behavior while retaining a managed, cross-platform architecture.

ed and red follow the GNU ed 1.22.5 command-line and editing profile implemented by the project. red is not a separate editing engine: it invokes the same Ed-family engine through a permanently restricted capability profile.

sed follows GNU sed command and option conventions where implemented, including addressed commands, BRE/ERE operation, substitutions, branching, pattern and hold spaces, GNU address extensions, in-place editing, sandbox mode, and NUL-delimited input. Its core work is performed in process; it does not shell out to another sed implementation.

Platform-sensitive command mechanics are supplied by .NET and the published Icod.CommandFramework package. Unsupported host capabilities are surfaced explicitly rather than emulated by invoking neighboring Unix tools.

Highlights

ed

ed supports standard and extended regular expressions, traditional compatibility mode, prompting, quiet/script/verbose modes, initial addresses, controlled filename policy, optional CR stripping, shell commands and filters in the standard profile, and --restricted for the same capability boundary used by red.

red

red is always restricted. It disables shell execution before mutable editor dispatch and permits only simple leaf filenames under a captured working-directory policy. The restriction is a pathname-policy boundary; it does not claim physical confinement across symbolic links, mount points, hard links, reparse points, or validation/open races.

sed

sed supports script expressions and files, automatic-print suppression, GNU BRE/ERE selection, in-place editing with optional backup suffixes, separate-file processing, unbuffered output, NUL-delimited records, list-width control, GNU address forms, and sandbox mode. Record framing is byte preserving and independent of host newline conventions.

Building

The repository requires a .NET 10 SDK.

On Windows:

build.cmd

On Unix-like hosts:

./build.sh

With no section argument, the wrappers use Debug and run:

clean → restore → build → test → pack → validate

The individual clean, restore, build, test, pack, and validate stages may also be requested.

Or build the solution directly:

dotnet restore Icod.LineEditor.sln
dotnet build Icod.LineEditor.sln -c Staging --no-restore
dotnet test Icod.LineEditor.sln -c Staging --no-build --no-restore

The solution defines Debug, Staging, and Release configurations. Release builds treat compiler warnings as errors except for documentation warning CS1591.

Versioning

Repository versioning is centralized in the root Directory.Build.props. VersionPrefix is the single authoritative release-version literal and is currently 1.1.1. Version, PackageVersion, AssemblyVersion, and FileVersion are derived from it for projects in the repository.

For a tagged release, the v<semver> tag must agree with the generated NuGet package version. The release workflow selects packages by their actual nuspec version, so a mismatched tag cannot silently publish a differently versioned package.

Continuous integration and release

The repository follows the canonical uniblab/.github lifecycle:

• pull requests build and test Staging on Windows, Linux, and macOS; Linux additionally packs and verifies generated NuGet artifacts;
• pushes to main run Release distribution validation on Windows/Linux/macOS for x64 and ARM64; and
• v<semver> tags contained in the default branch run the Release package/archive publication graph.

Executable release archives are produced for win-x64, win-arm64, linux-x64, linux-arm64, osx-x64, and osx-arm64. Each archive contains lineeditor, ed, red, and sed (with .exe suffixes on Windows), plus the repository README.md and LICENSE.

The Icod.LineEditor.Tools router is a .NET tool package whose installed command is lineeditor. Package publication is version-gated by the actual generated nuspec version. NuGet.org Trusted Publishing must authorize the Icod.LineEditor.Tools package for repository uniblab/Icod.LineEditor, workflow release.yaml, and environment Release.

See packaging/README.md for the complete build, validation, archive, package-publication, and release contract.

Project layout

Icod.LineEditor/
├── Directory.Build.props          centralized repository version
├── Icod.LineEditor.Ed.Shared/    mutable Ed/Red engine
├── ed/                           standard line editor
├── red/                          restricted line editor
├── sed/                          stream editor
├── lineeditor/                   ed/red/sed command router
├── tests/                        command, engine, and router tests
├── packaging/                    normalized build/distribution helpers
├── docs/history/                 retained architecture and migration history
├── Icod.LineEditor.sln
├── build.cmd
└── build.sh

Documentation

The executable READMEs are intended to function much like concise manual pages:

• lineeditor/README.md
• ed/README.md
• red/README.md
• sed/README.md

For the reusable Ed-family engine, see Icod.LineEditor.Ed.Shared/README.md. The detailed design and migration record is preserved under docs/history.

Licensing

The executable tools lineeditor, ed, red, and sed are distributed under the GNU General Public License, version 3 or later. Each standalone tool directory contains its own LICENSE file, and the repository root LICENSE contains the same GPL text used by the router distribution.

Icod.LineEditor.Ed.Shared is distributed under the GNU Lesser General Public License, version 3 or later. See Icod.LineEditor.Ed.Shared/LICENSE.

The Icod.LineEditor.Tools NuGet package includes the repository root README.md and LICENSE. Runtime-specific executable archives likewise include the root README.md and LICENSE alongside lineeditor, ed, red, and sed.

Upstream inspiration and authorship

GNU ed identifies Andrew L. Moore as the original GNU ed author and Antonio Diaz Diaz as its current maintainer. red is the restricted form of GNU ed and shares that implementation lineage rather than having a separate upstream author list.

GNU sed 4.9 identifies Jay Fenlason, Tom Lord, Ken Pizzini, Paolo Bonzini, Jim Meyering, and Assaf Gordon as its authors. The historical Unix sed lineage originated with Lee E. McMahon.

These upstream credits identify the authors of the programs and implementations on which this managed work is modeled; they do not imply authorship of the C# migration.

Migrated to .Net by Timothy J. Bruce uniblab@hotmail.com.

Copyright

Copyright (c) 2026 Timothy J. Bruce