golang.org/x/sys v0.0.0-20191026070338-33540a1f6037

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify pkg:golang/golang.org/x/sys@v0.0.0-20191026070338-33540a1f6037
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/sys@v0.0.0-20191026070338-33540a1f6037

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:b4c44b6b4e4aa15a5252b7660af056594ab1fdb354fa07497a965594d69313aa","contract":["unix.Uname populates unix.Utsname with non-empty NUL-terminated system and machine metadata","unix.ByteSliceFromString converts valid strings to NUL-terminated byte slices and returns unix.EINVAL for embedded NUL bytes","unix.Getpid returns a positive process ID matching os.Getpid","unix.Pipe creates a file descriptor pair that round-trips bytes across unix.Write and unix.Read"],"goal":"verify pkg:golang/golang.org/x/sys@v0.0.0-20191026070338-33540a1f6037","kind":"HOW","packages":["pkg:golang/golang.org/x/sys@v0.0.0-20191026070338-33540a1f6037"],"schemaVersion":1},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/golang.org/x/sys@v0.0.0-20191026070338-33540a1f6037"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/sys@v0.0.0-20191026070338-33540a1f6037","verifierAdapter":"golang@1"}

module example.com/sample

go 1.22

require golang.org/x/sys v0.0.0-20191026070338-33540a1f6037

golang.org/x/sys v0.0.0-20191026070338-33540a1f6037 h1:YyJpGZS1sBuBCzLAR1VEpK193GlqGZbnPFnPV/5Rsb4=
golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

package main

import (
	"bytes"
	"fmt"

	"golang.org/x/sys/unix"
)

func main() {
	var uts unix.Utsname
	if err := unix.Uname(&uts); err != nil {
		panic(err)
	}
	sysname := string(bytes.TrimRight(uts.Sysname[:], "\x00"))
	fmt.Printf("System: %s (PID %d)\n", sysname, unix.Getpid())
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/golang.org/x/sys@v0.0.0-20191026070338-33540a1f6037",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/sys@v0.0.0-20191026070338-33540a1f6037"
  ]
}

package main

import (
	"bytes"
	"errors"
	"fmt"
	"os"

	"golang.org/x/sys/unix"
)

func cString(b []byte) string {
	if i := bytes.IndexByte(b, 0); i >= 0 {
		return string(b[:i])
	}
	return string(b)
}

func main() {
	// 1. unix.Uname populates unix.Utsname with NUL-terminated system and machine metadata
	var uts unix.Utsname
	if err := unix.Uname(&uts); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: unix.Uname returned unexpected error: %v\n", err)
		os.Exit(1)
	}
	sysname := cString(uts.Sysname[:])
	machine := cString(uts.Machine[:])
	if sysname == "" || machine == "" {
		fmt.Fprintf(os.Stderr, "FAIL: expected non-empty sysname (%q) and machine (%q)\n", sysname, machine)
		os.Exit(1)
	}

	// 2. unix.ByteSliceFromString converts valid strings to NUL-terminated byte slices and rejects embedded NUL with unix.EINVAL
	slice, err := unix.ByteSliceFromString("posix")
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: ByteSliceFromString failed for valid string: %v\n", err)
		os.Exit(1)
	}
	if len(slice) != 6 || slice[5] != 0 || string(slice[:5]) != "posix" {
		fmt.Fprintf(os.Stderr, "FAIL: unexpected ByteSliceFromString result: %v\n", slice)
		os.Exit(1)
	}
	_, err = unix.ByteSliceFromString("bad\x00string")
	if !errors.Is(err, unix.EINVAL) {
		fmt.Fprintf(os.Stderr, "FAIL: expected unix.EINVAL for embedded NUL byte, got %v\n", err)
		os.Exit(1)
	}

	// 3. unix.Getpid returns positive process ID matching os.Getpid
	pid := unix.Getpid()
	if pid <= 0 || pid != os.Getpid() {
		fmt.Fprintf(os.Stderr, "FAIL: unix.Getpid() = %d, expected %d\n", pid, os.Getpid())
		os.Exit(1)
	}

	// 4. unix.Pipe creates a working file descriptor pair for reading and writing bytes
	var fds [2]int
	if err := unix.Pipe(fds[:]); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: unix.Pipe failed: %v\n", err)
		os.Exit(1)
	}
	defer unix.Close(fds[0])
	defer unix.Close(fds[1])

	payload := []byte("csx-sys-check")
	n, err := unix.Write(fds[1], payload)
	if err != nil || n != len(payload) {
		fmt.Fprintf(os.Stderr, "FAIL: unix.Write wrote %d bytes, err=%v\n", n, err)
		os.Exit(1)
	}
	buf := make([]byte, len(payload))
	n, err = unix.Read(fds[0], buf)
	if err != nil || n != len(payload) || string(buf) != string(payload) {
		fmt.Fprintf(os.Stderr, "FAIL: unix.Read read %q (%d bytes), err=%v\n", string(buf[:n]), n, err)
		os.Exit(1)
	}

	fmt.Println("PASS")
}