gcc/libgo/go/os/exec/lp_plan9.go
Ian Lance Taylor cfcbb4227f libgo: update to Go1.16beta1 release
This does not yet include support for the //go:embed directive added
in this release.

	* Makefile.am (check-runtime): Don't create check-runtime-dir.
	(mostlyclean-local): Don't remove check-runtime-dir.
	(check-go-tool, check-vet): Copy in go.mod and modules.txt.
	(check-cgo-test, check-carchive-test): Add go.mod file.
	* Makefile.in: Regenerate.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/280172
2020-12-30 15:13:24 -08:00

57 lines
1.4 KiB
Go

// 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"
"io/fs"
"os"
"path/filepath"
"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 fs.ErrPermission
}
// LookPath searches for an executable 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.
// The result may be an absolute path or a path relative to the current directory.
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 filepath.SplitList(path) {
path := filepath.Join(dir, file)
if err := findExecutable(path); err == nil {
return path, nil
}
}
return "", &Error{file, ErrNotFound}
}