Rename cpx → copy, flatten the CLI, and add Nix/AUR/Guix packaging

.github/workflows/release.yml

@@ -23,7 +23,7 @@ jobs:
       - name: Create Release
         uses: softprops/action-gh-release@v1
         with:
-          name: cpx v${{ steps.get_version.outputs.version }}
+          name: copy v${{ steps.get_version.outputs.version }}
           generate_release_notes: true
 
   build-release:
@@ -34,20 +34,20 @@ jobs:
         include:
           - os: ubuntu-latest
             target: x86_64-unknown-linux-gnu
-            artifact_name: cpx
-            asset_name: cpx-linux-x86_64
+            artifact_name: copy
+            asset_name: copy-linux-x86_64
           - os: ubuntu-latest
             target: x86_64-unknown-linux-musl
-            artifact_name: cpx
-            asset_name: cpx-linux-x86_64-musl
+            artifact_name: copy
+            asset_name: copy-linux-x86_64-musl
           - os: ubuntu-latest
             target: aarch64-unknown-linux-gnu
-            artifact_name: cpx
-            asset_name: cpx-linux-aarch64
+            artifact_name: copy
+            asset_name: copy-linux-aarch64
           - os: ubuntu-latest
             target: armv7-unknown-linux-gnueabihf
-            artifact_name: cpx
-            asset_name: cpx-linux-armv7
+            artifact_name: copy
+            asset_name: copy-linux-armv7
 
     steps:
       - uses: actions/checkout@v3

.gitignore

@@ -1 +1,8 @@
 /target
+
+# Nix build outputs
+/result
+/result-*
+
+# Guix vendored crate sources (generated by `cargo vendor guix/vendor`)
+/guix/vendor

CLAUDE.md

@@ -0,0 +1,84 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## What this is
+
+`copy` is a modern, parallel `cp` replacement for Linux, written in Rust (edition 2024). Explicit binary `[[bin]] name = "copy"` (`src/main.rs`) plus a library (`src/lib.rs`, crate name `copy`) that holds all the logic so it can be unit-tested. The binary is a thin shell: parse args → validate → dispatch to `core::copy`.
+
+This is a fork: `origin` is `github.com/UnbreakableMJ/copy`, `upstream` is `github.com/11happy/cpx`. License is MIT (not the umbrella GPL/Standard posture — this crate predates and lives outside the Spacecraft Software Standard; do not retrofit Standard headers/posture files here unless asked).
+
+## Commands
+
+```bash
+cargo build                       # debug build
+cargo build --release             # optimized binary at target/release/copy
+cargo test                        # all unit + integration tests
+cargo test test_copy_single_file  # run one test by name
+cargo test --test intergration    # integration suite only (note: file is mis-spelled "intergration.rs")
+cargo clippy -- -D warnings       # CI gate: warnings are errors
+cargo fmt -- --check              # CI gate: formatting (rustfmt.toml uses defaults)
+cargo run -- -r src_dir/ dst_dir/ # run locally; args after `--` go to copy
+```
+
+CI (`.github/workflows/ci.yml`) runs exactly: build → test → `clippy -D warnings` → `fmt --check`. All four must pass.
+
+The `selinux-support` feature is **off by default** and gates the `selinux` dependency:
+```bash
+cargo build --features selinux-support
+```
+
+### GNU compatibility tests
+
+`tests/gnu/*.sh` are standalone shell scripts (reimplementations of coreutils `cp` tests) that invoke a `copy` binary on `PATH` — they are **not** wired into `cargo test`. To run one, build first and put the binary on PATH:
+```bash
+cargo build --release
+PATH="$PWD/target/release:$PATH" sh tests/gnu/abuse.sh
+```
+
+## Architecture
+
+Two-phase pipeline: **plan, then execute.** Nothing is copied until a complete `CopyPlan` is built; this is what makes parallelism, resume, and conflict-detection tractable.
+
+```
+main.rs            → installs SIGINT/SIGTERM handler that flips an AtomicBool ("abort"),
+                     then calls copy() / multiple_copy()
+cli/args.rs        → CLIArgs::parse (copy is the root action; `config` subcommand intercepted),
+                     validate() → (sources, destination, CopyOptions)
+config/            → layered config load, merged BEFORE cli overrides
+utility/preprocess → walks the tree (jwalk), builds CopyPlan (files/dirs/symlinks/hardlinks)
+core/copy.rs       → execute_copy(): rayon thread pool fans plan.files out to copy_core()
+core/fast_copy.rs  → Linux copy_file_range() zero-copy fast path
+utility/preserve   → applies mode/ownership/timestamps/xattr/ACL/SELinux after each copy
+```
+
+### Options precedence (in `args.rs::validate`)
+`CopyOptions::none()` defaults → overlaid by `from_config()` if a config file applies → overlaid by `apply_cli_overrides(&mut options, &CLIArgs)` (CLI always wins) → `validate_conflicts()`. The two constructors (`none`, `from_config`) must stay in sync when you add a field to `CopyOptions` — there is no derive doing this. The unit tests in `args.rs` construct `CLIArgs` with every field listed explicitly, so adding a copy field touches those tests too.
+
+### CLI structure (flattened: copy is root, `config` is the only subcommand)
+Copy is the **root** command — `copy <src> <dst>` — so `CLIArgs` holds the copy args directly, plus `command: Option<Commands>` for the `config` subcommand (`copy config show`). Because `sources` is a greedy variadic that would swallow `config show` as two paths, `CLIArgs::parse()` special-cases a **leading** `config` argument and routes it through the dedicated `ConfigInvocation` parser (then `with_config()` builds a config-mode `CLIArgs`); everything else is parsed as a copy invocation. `validate()` runs the config subcommand and exits when `command` is `Some`, otherwise returns the copy inputs. The `command` field is still declared on `CLIArgs` so `--help` lists `config`. Consequence: a source literally named `config` as the first argument must be written `./config`.
+
+### CopyPlan construction (`preprocess.rs`)
+`preprocess_file` / `preprocess_directory` / `preprocess_multiple` produce a `CopyPlan`. Key invariants:
+- **Last source wins:** `add_file_with_inode` calls `remove_existing_task` first, so a later source targeting the same destination replaces earlier file/symlink/hardlink tasks (prevents symlink write-through bugs — see `tests/gnu/abuse.sh`).
+- **Resume:** when `options.resume`, `should_skip_file` compares xxh3 (`Xxh3`) checksums of source vs existing destination and marks the file skipped instead of queuing it.
+- **Hard-link preservation** (`preserve.links`): files with `nlink > 1` are grouped by inode in `inode_groups`; at execution a `HardLinkTracker` (behind a `Mutex`) creates a hardlink for the 2nd+ member instead of re-copying.
+- Mutually exclusive routing: a `FileTask` becomes a symlink, hardlink, resume-skip, or real copy — decided here, not at execution time.
+
+### Execution & concurrency (`core/copy.rs::execute_copy`)
+- Directories are created sequentially first, then files are copied in parallel via a `rayon::ThreadPoolBuilder` sized to `options.parallel` (`-j`).
+- `--interactive` forces a **sequential** path (prompts can't be parallel).
+- Per file, `copy_core` tries in order: hardlink-tracker shortcut → reflink (`reflink_copy`) → `fast_copy` (Linux `copy_file_range`) → buffered read/write fallback. Buffer size scales with file size (64 KiB → 2 MiB).
+- **Cooperative cancellation:** every copy loop polls `options.abort` (the AtomicBool from `main.rs`); on abort it deletes the partial destination and returns `io::ErrorKind::Interrupted`. `main.rs` maps that to exit code **130** and prints the `--resume` hint. Other errors → exit **1**.
+- Errors from parallel workers are collected, not fail-fast; up to 3 are printed.
+
+### Errors (`error.rs`)
+Domain-specific enums (`CopyError`, `ConfigError`, `ExcludeError`, `PreserveError`) each with a `*Result<T>` alias, funneled into the top-level `CliError`. Add new failure modes to the matching enum rather than stringly-typing.
+
+## Conventions
+
+- **Platform:** Linux-first. Linux-only code (`fast_copy`, `copy_file_range`) is behind `#[cfg(target_os = "linux")]`; unix-only metadata behind `#[cfg(unix)]`. Keep new platform-specific code gated so the crate still type-checks elsewhere.
+- **Edition 2024** idioms are used heavily — `let ... &&` let-chains in `if`, `std::fs::exists`. Match the surrounding style.
+- Two README files: `README.md` (GitHub) and `README_CRATES.md` (the `readme =` in `Cargo.toml`, shown on crates.io). Update both when user-facing behavior changes.
+- User-facing docs live in `docs/` (`configuration.md`, `examples.md`, `benchmarks.md`); benchmark scripts/results in `benchmarks/`.
+- **Packaging:** `flake.nix` + `nix/package.nix` (Nix; `nix/package.nix` is the single `callPackage` derivation shared by the flake package and `overlays.default`, built from a filtered local `src` with `cargoLock.lockFile = ../Cargo.lock`), `packaging/aur/PKGBUILD` + `.SRCINFO` (Arch, build-from-source), and `guix.scm` (GNU Guix; builds offline against a locally vendored `guix/vendor` dir — run `cargo vendor guix/vendor` first, it's gitignored). When bumping the crate version, update `version` in `nix/package.nix`, `pkgver` in the PKGBUILD/`.SRCINFO`, and `version` in `guix.scm` to match `Cargo.toml`. Regenerate `.SRCINFO` with `makepkg --printsrcinfo`. Note: Guix needs `rust` ≥ 1.85 for edition 2024.

CONTRIBUTING.md

@@ -1,23 +1,23 @@
-# Contributing to CPX
+# Contributing to Copy
 
-Thanks for your interest in making CPX better! 🎉
+Thanks for your interest in making Copy better! 🎉
 
 ## Ways to Contribute
 
 ### 🐛 Report Bugs
 
 Found a bug? Help us fix it:
-1. Check [existing issues](https://github.com/11happy/cpx/issues) first
+1. Check [existing issues](https://github.com/UnbreakableMJ/copy/issues) first
 2. Open a new issue with:
    - What you expected to happen
    - What actually happened
    - Steps to reproduce
-   - Your OS and CPX version (`cpx --version`)
+   - Your OS and Copy version (`copy --version`)
 
 ### 💡 Request Features
 
 Have an idea? We'd love to hear it:
-1. Check [existing issues](https://github.com/11happy/cpx/issues) for similar requests
+1. Check [existing issues](https://github.com/UnbreakableMJ/copy/issues) for similar requests
 2. Open a new issue describing:
    - The feature you want
    - Why it would be useful
@@ -36,8 +36,8 @@ Ready to contribute code? Great!
 #### Setup
 ```bash
 # Fork and clone
-git clone https://github.com/11happy/cpx
-cd cpx
+git clone https://github.com/UnbreakableMJ/copy
+cd copy
 
 # Build and test
 cargo build

Cargo.toml

@@ -1,14 +1,18 @@
 [package]
-name = "cpx"
+name = "copy"
 description = "A modern, fast file copying tool"
-repository = "https://github.com/11happy/cpx"
+repository = "https://github.com/UnbreakableMJ/copy"
 readme = "README_CRATES.md"
 keywords = ["copy", "file", "cli", "backup", "utility"]
 version = "0.1.4"
 authors = ["Bhuminjay Soni <bhuminjaysoni@gmail.com>"]
 license = "MIT"
 edition = "2024"
 
+[[bin]]
+name = "copy"
+path = "src/main.rs"
+
 [dependencies]
 clap = { version = "4.5.53", features = ["derive"] }
 filetime = "0.2.26"