golang.org/x/sys v0.40.0: unix.Getppid

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.Getppid in pkg:golang/golang.org/x/sys@v0.40.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/sys@v0.40.0
Demonstrate these symbols/APIs:
  - golang.org/x/sys/unix.Getppid

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:sha256:53bc710ea9f341a5271253c733102b43bb0720b5d805f6b5cc38cbf7156233d2","contract":["unix.Getppid returns the parent process ID matching a positive integer","unix.Getppid returns the identical parent process ID matching os.Getppid","unix.Getppid produces consistent and idempotent results across consecutive invocations"],"goal":"verify golang.org/x/sys/unix.Getppid in pkg:golang/golang.org/x/sys@v0.40.0","kind":"HOW","packages":["pkg:golang/golang.org/x/sys@v0.40.0"],"schemaVersion":1,"symbols":["golang.org/x/sys/unix.Getppid"]},"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@v0.40.0"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/sys@v0.40.0","symbols":["golang.org/x/sys/unix.Getppid"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.24.0

require golang.org/x/sys v0.40.0

golang.org/x/sys v0.40.0 h1:DBZZqJ2Rkml6QMQsZywtnjnnGvHza6BTfYFWY9kjEWQ=
golang.org/x/sys v0.40.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=

package main

import (
	"fmt"

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

// GetParentProcessID returns the caller's parent process ID using unix.Getppid.
func GetParentProcessID() int {
	return unix.Getppid()
}

func main() {
	ppid := GetParentProcessID()
	fmt.Printf("Parent Process ID: %d\n", ppid)
}

{
  "schemaVersion": 1,
  "goal": "verify golang.org/x/sys/unix.Getppid in pkg:golang/golang.org/x/sys@v0.40.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/sys@v0.40.0"
  ],
  "symbols": [
    "golang.org/x/sys/unix.Getppid"
  ]
}

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.Getppid returns the parent process ID matching a positive integer
	ppid := unix.Getppid()
	if ppid <= 0 {
		return fmt.Errorf("expected unix.Getppid() > 0, got %d", ppid)
	}

	// 2. unix.Getppid returns the identical parent process ID matching os.Getppid
	expectedPpid := os.Getppid()
	if ppid != expectedPpid {
		return fmt.Errorf("expected unix.Getppid() (%d) to equal os.Getppid() (%d)", ppid, expectedPpid)
	}

	// 3. unix.Getppid produces consistent and idempotent results across consecutive invocations
	for i := 0; i < 5; i++ {
		nextPpid := unix.Getppid()
		if nextPpid != ppid {
			return fmt.Errorf("inconsistent unix.Getppid() on iteration %d: expected %d, got %d", i, ppid, nextPpid)
		}
	}

	return nil
}