Add userspace /bin/cat and /bin/ls by dburkart · Pull Request #909 · dburkart/vibix

dburkart · 2026-05-06T05:16:07Z

Closes #902
Closes #903

Summary

Add base/cat/ — a minimal cat implementation that reads files from argv to stdout, or copies stdin to stdout when no args are given. Handles errors (file not found prints to stderr, exits 1).
Add base/ls/ — a minimal ls implementation that lists directory entries sorted alphabetically, one per line, with / suffix for directories. Supports multiple path args with headers; defaults to . when no args given.
Both crates follow the established base/sh/ pattern: standalone packages with #![feature(restricted_std)], built out-of-tree with -Z build-std against the in-repo std fork.
Both include a minimal syscalls.rs module providing the close C-ABI shim needed by the std PAL's OwnedFd::drop.
Wire both binaries into the ext2 rootfs image via xtask (build_userspace_cat() / build_userspace_ls()), installed alongside /bin/sh in all code paths that assemble the rootfs.

Test plan

cargo xtask build — full kernel build succeeds
cargo fmt --all -- --check — no formatting issues
cargo test -p xtask — all 71 xtask tests pass
Both cat and ls binaries compile successfully for the x86_64-unknown-vibix target

Implement cat and ls as standalone base system programs following the established base/sh pattern. Both use the in-repo std fork via -Z build-std and provide minimal syscall shims (close) needed by the std PAL. cat: reads files from argv to stdout; reads stdin if no args; supports "-" for explicit stdin; prints errors to stderr and exits 1 on failure. ls: lists directory entries sorted alphabetically, one per line, with "/" suffix for directories; supports multiple path args with headers; defaults to "." when no args given. Both binaries are wired into the ext2 rootfs image via xtask alongside /bin/sh, installed as /bin/cat and /bin/ls respectively. Closes #902 Closes #903 Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

coderabbitai · 2026-05-06T05:16:20Z

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: c97fea48-e97d-44e4-b3c2-3a0322594302

📥 Commits

Reviewing files that changed from the base of the PR and between 1c7ca82 and a410939.

📒 Files selected for processing (3)

base/cat/src/main.rs
base/ls/src/main.rs
xtask/src/main.rs

📝 Walkthrough

Walkthrough

Adds two new user-space command-line utilities (/bin/cat and /bin/ls) to the vibix ecosystem. Each includes a Cargo manifest, Rust implementation with restricted_std and syscall shims for POSIX-like close semantics, and integration into the xtask build system for inclusion in ext2 rootfs test images.

Changes

Userspace Cat and Ls Utilities

Layer / File(s)	Summary
Project Manifests `base/cat/Cargo.toml`, `base/ls/Cargo.toml`	Define standalone packages with name, version 0.1.0, edition 2021, authors, MIT OR Apache-2.0 license, and binary targets at src/main.rs.
Core Implementation `base/cat/src/main.rs`, `base/ls/src/main.rs`	cat: implements `cat_reader()` to stream data in 4 KiB chunks and `main()` to parse args, read stdin or files, handle "-" as stdin, and exit with error status. ls: implements `list_dir()` to read directory entries, sort by name, append "/" suffix to directories, and `main()` to list current or specified paths with optional headers for multiple arguments.
Syscalls Integration `base/cat/src/syscalls.rs`, `base/ls/src/syscalls.rs`	Both provide identical C-ABI syscall shims: `SYS_CLOSE` constant, `__errno_location()` extern declaration, `raw1()` syscall dispatcher via inline assembly, `cvt()` errno conversion, and public no_mangle `close(fd: i32) -> i32` function for vibix libc compatibility.
Build & Deploy Wiring `xtask/src/main.rs`	Adds `build_userspace_cat()` and `build_userspace_ls()` helper functions following the cargo-build-strip pattern, and updates run_with_root, smoke, and sh_test paths to build and include both binaries in the ext2 rootfs image at `/bin/cat` and `/bin/ls`.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

dburkart/vibix#873: Introduces the base/ workspace layout and foundational build patterns that this PR extends with new cat and ls utilities.
dburkart/vibix#867: Implements vibix syscall wrappers and std/fs/process support including close(), which overlaps with the low-level C-ABI syscall shims added here.
dburkart/vibix#611: Establishes the deterministic ext2-image builder and xtask integration that this PR uses to package cat and ls into the rootfs.

🐰 A cat and ls in the bin
Ready to read and to list
With syscalls that grin
And errors dismissed—
The userspace tools now begin! 📂📖

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarizes the main change: adding two new userspace binaries (/bin/cat and /bin/ls) to the system.
Description check	✅ Passed	The description is well-detailed and directly related to the changeset, explaining the implementation of cat and ls utilities, their patterns, integration into xtask, and test results.
Linked Issues check	✅ Passed	The PR successfully implements all coding requirements from issues `#902` and `#903`: cat/ls binaries following base/sh/ pattern, stdin/argv file reading, error handling, directory listing with trailing slashes, syscalls.rs close() shim, and xtask wiring.
Out of Scope Changes check	✅ Passed	All changes are directly in scope: two new utility crate implementations (cat and ls) following established patterns, syscalls modules, and xtask integration. No unrelated modifications detected.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

Create PR with unit tests
Commit unit tests in branch m902-userspace-cat-ls

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coderabbitai

Actionable comments posted: 1

🧹 Nitpick comments (2)

xtask/src/main.rs (1)
846-930: ⚡ Quick win

Factor the standalone userspace build flow into one helper.

build_userspace_cat, build_userspace_ls, and build_userspace_sh now all carry the same out-of-tree build-std/target-dir/strip sequence. That makes the next flag or path tweak easy to update in one helper and miss in the others.
🤖 Prompt for AI Agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@xtask/src/main.rs` around lines 846 - 930, The three functions
build_userspace_cat, build_userspace_ls and build_userspace_sh duplicate the
same out-of-tree cargo invocation, target-dir handling, existence check and
strip_debug sequence; factor those common steps into a single helper (e.g.
build_userspace_bin or build_userspace_crate) that accepts the manifest path and
desired binary name (or crate dir) and returns the PathBuf, then replace
build_userspace_cat and build_userspace_ls to call that helper; ensure the
helper reproduces workspace_root(), VIBIX_USERSPACE_TARGET usage, sets
__CARGO_TESTS_ONLY_SRC_ROOT, runs the same cargo args, invokes
check(cmd.status()?) , verifies the binary exists at
target_dir.join("x86_64-unknown-vibix").join("debug").join(bin_name"), calls
strip_debug(&bin) and returns Ok(bin).
base/cat/src/main.rs (1)
23-64: ⚡ Quick win

Prefer returning ExitCode from main — it's more idiomatic than calling process::exit().

While this code works correctly (Rust's standard library ensures stdout is flushed during shutdown even when using process::exit()), returning ExitCode from main follows Rust conventions and avoids the less common exit path. No correctness risk here.
🤖 Prompt for AI Agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@base/cat/src/main.rs` around lines 23 - 64, Change main to return
std::process::ExitCode instead of calling process::exit(): update the signature
of main to -> ExitCode, remove all process::exit(status) and process::exit(1)
calls, and at the end return ExitCode::from(status) (or return ExitCode::SUCCESS
/ ExitCode::from(1) where appropriate). Ensure you import std::process::ExitCode
or fully qualify it, and keep the existing logic in functions like cat_reader
unchanged while mapping the final integer status to an ExitCode.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@base/ls/src/main.rs`:
- Around line 50-73: The main function currently calls process::exit(status)
which bypasses normal stdio flushing; change main to return
std::process::ExitCode instead of calling process::exit. Keep the existing loop
and use the same status variable (or make it i32/u8 as you prefer), then at the
end return ExitCode::from(status as u8) (convert the final status to u8) and
remove the process::exit call; this preserves list_dir and its returns but
ensures stdout/stderr are flushed before exit.

---

Nitpick comments:
In `@base/cat/src/main.rs`:
- Around line 23-64: Change main to return std::process::ExitCode instead of
calling process::exit(): update the signature of main to -> ExitCode, remove all
process::exit(status) and process::exit(1) calls, and at the end return
ExitCode::from(status) (or return ExitCode::SUCCESS / ExitCode::from(1) where
appropriate). Ensure you import std::process::ExitCode or fully qualify it, and
keep the existing logic in functions like cat_reader unchanged while mapping the
final integer status to an ExitCode.

In `@xtask/src/main.rs`:
- Around line 846-930: The three functions build_userspace_cat,
build_userspace_ls and build_userspace_sh duplicate the same out-of-tree cargo
invocation, target-dir handling, existence check and strip_debug sequence;
factor those common steps into a single helper (e.g. build_userspace_bin or
build_userspace_crate) that accepts the manifest path and desired binary name
(or crate dir) and returns the PathBuf, then replace build_userspace_cat and
build_userspace_ls to call that helper; ensure the helper reproduces
workspace_root(), VIBIX_USERSPACE_TARGET usage, sets
__CARGO_TESTS_ONLY_SRC_ROOT, runs the same cargo args, invokes
check(cmd.status()?) , verifies the binary exists at
target_dir.join("x86_64-unknown-vibix").join("debug").join(bin_name"), calls
strip_debug(&bin) and returns Ok(bin).

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

Push a commit to this branch (recommended)
Create a new PR with the fixes

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: a34ea613-0fd0-4761-8e7b-b3f54eff88cb

📥 Commits

Reviewing files that changed from the base of the PR and between 46c38d0 and 1c7ca82.

📒 Files selected for processing (7)

base/cat/Cargo.toml
base/cat/src/main.rs
base/cat/src/syscalls.rs
base/ls/Cargo.toml
base/ls/src/main.rs
base/ls/src/syscalls.rs
xtask/src/main.rs

- Replace process::exit() with ExitCode return in cat and ls main functions to ensure stdout is flushed before exit. - Factor the duplicated out-of-tree build-std cargo invocation into build_userspace_std_bin() and call it from sh/cat/ls wrappers. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…and /bin/uname (#913) Closes #904 Closes #905 ## Summary - Add eight new base system programs following the cat/ls pattern from PR #909: `stat`, `cp`, `mv`, `rm`, `mkdir`, `rmdir`, `touch`, and `uname` - Each is a standalone crate in `base/<name>/` with its own `syscalls.rs` shim, built via the `build_userspace_std_bin()` helper - All binaries are wired into the ext2 rootfs across all four extras assembly sites (run ext2, run default, smoke, sh_test) - Updated ext2 image hash ### Utilities | Utility | Description | std API | |---------|-------------|---------| | `stat` | Print file type and size for paths | `fs::symlink_metadata()` | | `cp` | Copy a file (`cp <src> <dst>`) | `fs::copy()` | | `mv` | Move/rename a file (`mv <src> <dst>`) | `fs::rename()` | | `rm` | Remove files (`rm <path>...`) | `fs::remove_file()` | | `mkdir` | Create directories (`mkdir <path>...`) | `fs::create_dir()` | | `rmdir` | Remove empty directories (`rmdir <path>...`) | `fs::remove_dir()` | | `touch` | Create empty files if not exist | `OpenOptions::new().create(true).write(true).open()` | | `uname` | Print system info; `-a` for full | Hardcoded (no syscall yet) | ## Test plan - [x] `cargo xtask build` — passes - [x] `cargo xtask smoke` — all 43 markers present - [x] `cargo fmt --all -- --check` — clean - [x] `cargo xtask ext2-image` — hash updated and verified --------- Co-authored-by: vibix auto-engineer <noreply@anthropic.com>

coderabbitai Bot reviewed May 6, 2026

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Comment thread base/ls/src/main.rs Outdated

dburkart merged commit e7b3382 into main May 6, 2026
15 checks passed

dburkart deleted the m902-userspace-cat-ls branch May 6, 2026 05:33

dburkart mentioned this pull request May 6, 2026

Add userspace file utilities (stat, cp, mv, rm, mkdir, rmdir, touch) and /bin/uname #913

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Add userspace /bin/cat and /bin/ls#909

Add userspace /bin/cat and /bin/ls#909
dburkart merged 2 commits intomainfrom
m902-userspace-cat-ls

dburkart commented May 6, 2026

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dburkart commented May 6, 2026

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