package exec_test

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"os"
	"os/exec"
	"strings"
	"time"
)

func ExampleLookPath() {
	path, err := exec.LookPath("fortune")
	if err != nil {
		log.Fatal("installing fortune is in your future")
	}
	fmt.Printf("fortune is available at %s\n", path)
}

func ExampleCommand() {
	cmd := exec.Command("tr", "a-z", "A-Z")

// init finds the gccgo search directories. If this fails it leaves dirs == nil.
func (gd *gccgoDirs) init() {
	gccgo := os.Getenv("GCCGO")
	if gccgo == "" {
		gccgo = "gccgo"
	}
	bin, err := exec.LookPath(gccgo)
	if err != nil {
		return
	}

	allDirs, err := exec.Command(bin, "-print-search-dirs").Output()
	if err != nil {
		return
	}
	versionB, err := exec.Command(bin, "-dumpversion").Output()

	if strings.HasPrefix(p, prefix) {
		return true
	}
	return strings.HasPrefix(strings.ToLower(p), strings.ToLower(prefix))
}

func splitList(path string) []string {
	// The same implementation is used in LookPath in os/exec;
	// consider changing os/exec when changing this.

	if path == "" {
		return []string{}
	}

	// Split path, respecting but preserving quotes.
	list := []string{}
	start := 0
	quo := false

	registerMetrics()

	for _, provider := range credentialProviderConfig.Providers {
		// Considering Windows binary with suffix ".exe", LookPath() helps to find the correct path.
		// LookPath() also calls os.Stat().
		pluginBin, err := exec.LookPath(filepath.Join(pluginBinDir, provider.Name))
		if err != nil {
			if errors.Is(err, os.ErrNotExist) || errors.Is(err, exec.ErrNotFound) {

// That is, if you run [LookPath]("go"), it will not successfully return
// ./go on Unix nor .\go.exe on Windows, no matter how the path is configured.
// Instead, if the usual path algorithms would result in that answer,
// these functions return an error err satisfying [errors.Is](err, [ErrDot]).
//
// For example, consider these two program snippets:
//
//	path, err := exec.LookPath("prog")
//	if err != nil {

	"sync"
	"time"
)

type hgHandler struct {
	once      sync.Once
	hgPath    string
	hgPathErr error
}

func (h *hgHandler) Available() bool {
	h.once.Do(func() {
		h.hgPath, h.hgPathErr = exec.LookPath("hg")
	})
	return h.hgPathErr == nil
}

func (h *hgHandler) Handler(dir string, env []string, logger *log.Logger) (http.Handler, error) {
	if !h.Available() {
		return nil, ServerNotInstalledError{name: "hg"}
	}

	listenErr error
	conns     map[net.Conn]struct{}
	closing   bool
	done      chan struct{}
}

func (h *svnHandler) Available() bool {
	h.pathOnce.Do(func() {
		h.svnservePath, h.svnserveErr = exec.LookPath("svnserve")
	})
	return h.svnserveErr == nil
}

// Handler returns an http.Handler that checks for the "vcwebsvn" query
// parameter and then serves the 'svn://' URL for the repository at the
// requested path.

	}
	return parameters
}

// exec executes the conntrack tool using the given parameters
func (ct *execCT) exec(parameters ...string) error {
	conntrackPath, err := ct.execer.LookPath("conntrack")
	if err != nil {
		return fmt.Errorf("error looking for path of conntrack: %v", err)
	}
	klog.V(4).InfoS("Clearing conntrack entries", "parameters", parameters)

				exe = filepath.Join(tmpDir, "go.o")
			}

			darwinSymbolTestIsTooFlaky := true // Turn this off, it is too flaky -- See #32218
			if runtime.GOOS == "darwin" && !darwinSymbolTestIsTooFlaky {
				if _, err = exec.LookPath("symbols"); err == nil {
					// Ensure Apple's tooling can parse our object for symbols.
					out, err = testenv.Command(t, "symbols", exe).CombinedOutput()
					if err != nil {

// If not, MustHaveExecPath calls t.Skip with an explanation.
func MustHaveExecPath(t testing.TB, path string) {
	MustHaveExec(t)

	err, found := execPaths.Load(path)
	if !found {
		_, err = exec.LookPath(path)
		err, _ = execPaths.LoadOrStore(path, err)
	}
	if err != nil {
		t.Skipf("skipping test: %s: %s", path, err)
	}
}

// CleanCmdEnv will fill cmd.Env with the environment, excluding certain