95 lines
2.1 KiB
Go
95 lines
2.1 KiB
Go
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// Copyright 2010 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package lookpath
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import (
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"errors"
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"io/fs"
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"os"
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"path/filepath"
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"strings"
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)
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// ErrNotFound is the error resulting if a path search failed to find an executable file.
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var ErrNotFound = errors.New("executable file not found in %PATH%")
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func chkStat(file string) error {
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d, err := os.Stat(file)
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if err != nil {
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return err
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}
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if d.IsDir() {
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return fs.ErrPermission
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}
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return nil
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}
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func hasExt(file string) bool {
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i := strings.LastIndex(file, ".")
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if i < 0 {
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return false
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}
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return strings.LastIndexAny(file, `:\/`) < i
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}
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func findExecutable(file string, exts []string) (string, error) {
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if len(exts) == 0 {
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return file, chkStat(file)
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}
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if hasExt(file) {
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if chkStat(file) == nil {
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return file, nil
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}
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}
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for _, e := range exts {
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if f := file + e; chkStat(f) == nil {
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return f, nil
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}
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}
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return "", fs.ErrNotExist
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}
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// LookPath searches for an executable named file in the
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// directories named by the PATH environment variable.
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// If file contains a slash, it is tried directly and the PATH is not consulted.
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// LookPath also uses PATHEXT environment variable to match
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// a suitable candidate.
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// The result may be an absolute path or a path relative to the current directory.
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func LookPath2(file string, lenv Env) (string, error) {
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var exts []string
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x := lenv.Getenv(`PATHEXT`)
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if x != "" {
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for _, e := range strings.Split(strings.ToLower(x), `;`) {
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if e == "" {
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continue
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}
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if e[0] != '.' {
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e = "." + e
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}
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exts = append(exts, e)
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}
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} else {
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exts = []string{".com", ".exe", ".bat", ".cmd"}
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}
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if strings.ContainsAny(file, `:\/`) {
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if f, err := findExecutable(file, exts); err == nil {
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return f, nil
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} else {
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return "", &Error{file, err}
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}
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}
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if f, err := findExecutable(filepath.Join(".", file), exts); err == nil {
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return f, nil
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}
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path := lenv.Getenv("path")
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for _, dir := range filepath.SplitList(path) {
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if f, err := findExecutable(filepath.Join(dir, file), exts); err == nil {
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return f, nil
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}
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}
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return "", &Error{file, ErrNotFound}
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}
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