golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1: unix.BytePtrToString

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 golang.org/x/sys/unix.BytePtrToString in pkg:golang/golang.org/x/sys@v0.0.0-20210615035016-665e8c7367d1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/sys@v0.0.0-20210615035016-665e8c7367d1
Demonstrate these symbols/APIs:
  - golang.org/x/sys/unix.BytePtrToString

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:e239b2cd553edd560f1a916f3d47e4f310f3e47e637a47dee126a4cd58158348","contract":["unix.BytePtrToString converts a null-terminated byte sequence to the corresponding Go string","unix.BytePtrToString returns an empty string when the pointer is nil","unix.BytePtrToString returns an empty string when pointing directly to a null byte","unix.BytePtrToString stops reading at the first null byte in a buffer containing trailing bytes"],"goal":"verify golang.org/x/sys/unix.BytePtrToString in pkg:golang/golang.org/x/sys@v0.0.0-20210615035016-665e8c7367d1","kind":"HOW","packages":["pkg:golang/golang.org/x/sys@v0.0.0-20210615035016-665e8c7367d1"],"schemaVersion":1,"symbols":["golang.org/x/sys/unix.BytePtrToString"]},"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@v0.0.0-20210615035016-665e8c7367d1"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/sys@v0.0.0-20210615035016-665e8c7367d1","symbols":["golang.org/x/sys/unix.BytePtrToString"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.26.6

require golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1

golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1 h1:SrN+KX8Art/Sf4HNj6Zcz06G7VEz+7w9tdXTPOZ7+l4=
golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

package main

import (
	"fmt"

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

func main() {
	buf := []byte{'C', 'o', 'd', 'e', 'S', 'a', 'm', 'p', 'l', 'e', 'X', 0}
	str := unix.BytePtrToString(&buf[0])
	fmt.Printf("Converted string: %s\n", str)

	nilStr := unix.BytePtrToString(nil)
	fmt.Printf("Nil pointer converted length: %d\n", len(nilStr))
}

{
  "schemaVersion": 1,
  "goal": "verify golang.org/x/sys/unix.BytePtrToString in pkg:golang/golang.org/x/sys@v0.0.0-20210615035016-665e8c7367d1",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/sys@v0.0.0-20210615035016-665e8c7367d1"
  ],
  "symbols": [
    "golang.org/x/sys/unix.BytePtrToString"
  ]
}

package main

import (
	"fmt"
	"os"

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

func main() {
	if err := runTests(); err != nil {
		fmt.Fprintf(os.Stderr, "Contract test failed: %v\n", err)
		os.Exit(1)
	}
	fmt.Println("All contract assertions passed.")
}

func runTests() error {
	// 1. unix.BytePtrToString converts a null-terminated byte sequence to the corresponding Go string
	buf1 := []byte{'H', 'e', 'l', 'l', 'o', ',', ' ', 'W', 'o', 'r', 'l', 'd', '!', 0}
	str1 := unix.BytePtrToString(&buf1[0])
	if str1 != "Hello, World!" {
		return fmt.Errorf("expected 'Hello, World!', got %q", str1)
	}

	// 2. unix.BytePtrToString returns an empty string when the pointer is nil
	strNil := unix.BytePtrToString(nil)
	if strNil != "" {
		return fmt.Errorf("expected empty string for nil pointer, got %q", strNil)
	}

	// 3. unix.BytePtrToString returns an empty string when pointing directly to a null byte
	bufZero := []byte{0}
	strZero := unix.BytePtrToString(&bufZero[0])
	if strZero != "" {
		return fmt.Errorf("expected empty string for null byte, got %q", strZero)
	}

	// 4. unix.BytePtrToString stops reading at the first null byte in a buffer containing trailing bytes
	bufTrailing := []byte{'t', 'e', 's', 't', 0, 'i', 'g', 'n', 'o', 'r', 'e', 0}
	strTrailing := unix.BytePtrToString(&bufTrailing[0])
	if strTrailing != "test" {
		return fmt.Errorf("expected 'test', got %q", strTrailing)
	}

	return nil
}