func LookPath(file string) (string, error) {
	return lookPath(file, pathExt())
}

// lookExtensions finds windows executable by its dir and path.
// It uses LookPath to try appropriate extensions.
// lookExtensions does not search PATH, instead it converts `prog` into `.\prog`.
//
// If the path already has an extension found in PATHEXT,
// lookExtensions returns it directly without searching

package toolchain

import (
	"io/fs"
	"os"
	"path/filepath"
	"strings"
	"sync"

	"cmd/go/internal/gover"
)

// pathExts is a cached PATHEXT list.
var pathExts struct {
	once sync.Once
	list []string
}

func initPathExts() {
	var exts []string
	x := os.Getenv(`PATHEXT`)
	if x != "" {
		for _, e := range strings.Split(strings.ToLower(x), `;`) {
			if e == "" {
				continue
			}
			if e[0] != '.' {

		PATHEXT:   `.COM;.EXE;.BAT`,
		files:     []string{`p1\a.bat`, `p2\a.exe`},
		searchFor: `a`,
		want:      `p1\a.bat`,
	},
	{
		name:      "first PATHEXT entry",
		PATHEXT:   `.COM;.EXE;.BAT`,
		files:     []string{`p1\a.bat`, `p1\a.exe`, `p2\a.bat`, `p2\a.exe`},
		searchFor: `a`,
		want:      `p1\a.exe`,
	},
	{
		name:      "ignore dir with PATHEXT extension",

	}

	var pathExt []string
	var searchExt bool
	var isExecutable func(os.FileInfo) bool
	if runtime.GOOS == "windows" {
		// Use the test process's PathExt instead of the script's.
		// If PathExt is set in the command's environment, cmd.Start fails with
		// "parameter is invalid". Not sure why.
		// If the command already has an extension in PathExt (like "cmd.exe")

    // Simply putting PATH there isn't enough. Windows has case-insensitive env vars but something else fails if the Path variable is published as PATH for test tasks.
    OperatingSystem.current().pathVar,
    "PATHEXT",
)


val credentialsKeywords = listOf(
    "api_key",
    "access_key",
    "apikey",
    "accesskey",
    "password",
    "token",
    "credential",
    "auth"
)

// extensions from $env:PATHEXT (in order) and run that file with that extension.
// For example, if we have the file C:\\foo.bat, we can run C:\\foo.
// For these tests, .bat was chosen since it's one of the default values in $env.PATHEXT. .ps1 is
// not in that list, but it might be useful for flexvolumes to be able to handle powershell scripts.
// There's no argument count variable in batch. Instead, we can check that the n-th argument
// is an empty string.

	case "illumos", "solaris":
		return []string{"LD_LIBRARY_PATH", "LD_LIBRARY_PATH_32", "LD_LIBRARY_PATH_64"}
	case "windows":
		return []string{"SystemRoot", "COMSPEC", "PATHEXT", "WINDIR"}
	}
	return nil
}()

// Handler runs an executable in a subprocess with a CGI environment.
type Handler struct {
	Path string // path to the CGI executable

build:win_clang_xla --compiler=clang-cl
build:win_clang_xla --linkopt=/FORCE:MULTIPLE
build:win_clang_xla --host_linkopt=/FORCE:MULTIPLE
test:win_clang_xla --action_env=PATHEXT=.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC;.PY;.PYW
test:win_clang_xla --linkopt=/FORCE:MULTIPLE
test:win_clang_xla --host_linkopt=/FORCE:MULTIPLE

# Options to build TensorFlow 1.x or 2.x.

			cmd.Path = lp
		}
		if err != nil {
			cmd.Err = err
		}
	} else if runtime.GOOS == "windows" && filepath.IsAbs(name) {
		// We may need to add a filename extension from PATHEXT
		// or verify an extension that is already present.
		// Since the path is absolute, its extension should be unambiguous
		// and independent of cmd.Dir, and we can go ahead and cache the lookup now.
		//

	// unlike the modules in pkgMods, this module does not inherently exclude
	// any other module in pkgMods.
	mod module.Version

	err error
}

// errSet returns a pathSet containing the given error.
func errSet(err error) pathSet { return pathSet{err: err} }

// newQuery returns a new query parsed from the raw argument,
// which must be either path or path@version.
func newQuery(raw string) (*query, error) {