Subversion Repositories openrisc

// Copyright 2011 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.

package exec

import (

        "errors"

        "os"

        "strings"

)

// ErrNotFound is the error resulting if a path search failed to find an executable file.

var ErrNotFound = errors.New("executable file not found in $path")

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.EPERM

}

// LookPath searches for an executable binary named file

// in the directories named by the path environment variable.

// If file begins with "/", "#", "./", or "../", it is tried

// directly and the path is not consulted.

func LookPath(file string) (string, error) {

        // skip the path lookup for these prefixes

        skip := []string{"/", "#", "./", "../"}

        for _, p := range skip {

                if strings.HasPrefix(file, p) {

                        err := findExecutable(file)

                        if err == nil {

                                return file, nil

                        }

                        return "", &Error{file, err}

                }

        }

        path := os.Getenv("path")

        for _, dir := range strings.Split(path, "\000") {

                if err := findExecutable(dir + "/" + file); err == nil {

                        return dir + "/" + file, nil

                }

        }

        return "", &Error{file, ErrNotFound}

}