golang.org/x/sys v0.0.0-20181122145206-62eef0e2fa9b: unix.Getgid, unix.Getrlimit, unix.Getuid

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@v0.0.0-20181122145206-62eef0e2fa9b
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/sys@v0.0.0-20181122145206-62eef0e2fa9b
Demonstrate these symbols/APIs:
  - unix.Getgid
  - unix.Getrlimit
  - unix.Getuid
  - unix.Setrlimit

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:b57b4e61952554fb83a56dbe1d534eb27494050083ea60830334e8e1da03a60d","contract":["unix.Getuid returns a valid non-negative user identifier","unix.Getgid returns a valid non-negative group identifier","unix.Getrlimit retrieves current and maximum resource limits for open file descriptors","unix.Setrlimit updates resource limits within permissible boundaries"],"goal":"verify pkg:golang/golang.org/x/sys@v0.0.0-20181122145206-62eef0e2fa9b","kind":"HOW","packages":["pkg:golang/golang.org/x/sys@v0.0.0-20181122145206-62eef0e2fa9b"],"schemaVersion":1,"symbols":["unix.Getgid","unix.Getrlimit","unix.Getuid","unix.Setrlimit"]},"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@v0.0.0-20181122145206-62eef0e2fa9b"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/sys@v0.0.0-20181122145206-62eef0e2fa9b","symbols":["unix.Getgid","unix.Getrlimit","unix.Getuid","unix.Setrlimit"],"verifierAdapter":"golang@1"}

module sample

go 1.25.0

require golang.org/x/sys v0.0.0-20181122145206-62eef0e2fa9b

golang.org/x/sys v0.0.0-20181122145206-62eef0e2fa9b h1:MQE+LT/ABUuuvEZ+YQAMSXindAdUh7slEmAkup74op4=
golang.org/x/sys v0.0.0-20181122145206-62eef0e2fa9b/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=

package main

import (
	"fmt"
	"os"

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

func main() {
	uid := unix.Getuid()
	gid := unix.Getgid()

	var rlim unix.Rlimit
	if err := unix.Getrlimit(unix.RLIMIT_NOFILE, &rlim); err != nil {
		fmt.Fprintf(os.Stderr, "failed to get rlimit: %v\n", err)
		os.Exit(1)
	}

	fmt.Printf("UID: %d, GID: %d\n", uid, gid)
	fmt.Printf("RLIMIT_NOFILE: cur=%d, max=%d\n", rlim.Cur, rlim.Max)

	newRlim := rlim
	if err := unix.Setrlimit(unix.RLIMIT_NOFILE, &newRlim); err != nil {
		fmt.Fprintf(os.Stderr, "failed to set rlimit: %v\n", err)
		os.Exit(1)
	}
	fmt.Println("Successfully verified resource limits.")
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/golang.org/x/sys@v0.0.0-20181122145206-62eef0e2fa9b",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/sys@v0.0.0-20181122145206-62eef0e2fa9b"
  ],
  "symbols": [
    "unix.Getgid",
    "unix.Getrlimit",
    "unix.Getuid",
    "unix.Setrlimit"
  ]
}

package main

import (
	"fmt"
	"os"

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

func main() {
	if err := runContract(); err != nil {
		fmt.Fprintf(os.Stderr, "Contract verification failed: %v\n", err)
		os.Exit(1)
	}
	fmt.Println("All golang.org/x/sys/unix contract assertions passed.")
}

func runContract() error {
	// Assertion 1: unix.Getuid returns a valid non-negative user identifier
	uid := unix.Getuid()
	if uid < 0 {
		return fmt.Errorf("expected non-negative UID from unix.Getuid, got %d", uid)
	}

	// Assertion 2: unix.Getgid returns a valid non-negative group identifier
	gid := unix.Getgid()
	if gid < 0 {
		return fmt.Errorf("expected non-negative GID from unix.Getgid, got %d", gid)
	}

	// Assertion 3: unix.Getrlimit retrieves current and maximum resource limits for open file descriptors
	var rlim unix.Rlimit
	if err := unix.Getrlimit(unix.RLIMIT_NOFILE, &rlim); err != nil {
		return fmt.Errorf("unix.Getrlimit failed: %w", err)
	}
	if rlim.Max == 0 {
		return fmt.Errorf("expected non-zero RLIMIT_NOFILE Max, got %d", rlim.Max)
	}
	if rlim.Cur > rlim.Max {
		return fmt.Errorf("expected RLIMIT_NOFILE Cur (%d) <= Max (%d)", rlim.Cur, rlim.Max)
	}

	// Assertion 4: unix.Setrlimit updates resource limits within permissible boundaries
	newRlim := rlim
	if err := unix.Setrlimit(unix.RLIMIT_NOFILE, &newRlim); err != nil {
		return fmt.Errorf("unix.Setrlimit failed: %w", err)
	}

	return nil
}