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// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build aix || darwin || dragonfly || freebsd || linux || nacl || netbsd || openbsd || solaris
package execpath
import (
"os"
"path/filepath"
"strings"
)
func findExecutable(file string) error {
d, err := os.Stat(file)
if err != nil {
return err
}
if m := d.Mode(); !m.IsDir() && m&0111 != 0 {
return nil
}
return os.ErrPermission
}
// Look searches for an executable named file, using getenv to look up
// environment variables. If getenv is nil, os.Getenv will be used. If file
// contains a slash, it is tried directly and getenv will not be called. The
// result may be an absolute path or a path relative to the current directory.
func Look(file string, getenv func(string) string) (string, error) {
if getenv == nil {
getenv = os.Getenv
}
// NOTE(rsc): I wish we could use the Plan 9 behavior here
// (only bypass the path if file begins with / or ./ or ../)
// but that would not match all the Unix shells.
if strings.Contains(file, "/") {
err := findExecutable(file)
if err == nil {
return file, nil
}
return "", &Error{file, err}
}
path := getenv("PATH")
for _, dir := range filepath.SplitList(path) {
if dir == "" {
// Unix shell semantics: path element "" means "."
dir = "."
}
path := filepath.Join(dir, file)
if err := findExecutable(path); err == nil {
return path, nil
}
}
return "", &Error{file, ErrNotFound}
}
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