gcc/libgo/go/internal/execabs/execabs.go
2021-01-29 11:04:55 -08:00

71 lines
1.8 KiB
Go

// Copyright 2021 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 execabs is a drop-in replacement for os/exec
// that requires PATH lookups to find absolute paths.
// That is, execabs.Command("cmd") runs the same PATH lookup
// as exec.Command("cmd"), but if the result is a path
// which is relative, the Run and Start methods will report
// an error instead of running the executable.
package execabs
import (
"context"
"fmt"
"os/exec"
"path/filepath"
"reflect"
"unsafe"
)
var ErrNotFound = exec.ErrNotFound
type (
Cmd = exec.Cmd
Error = exec.Error
ExitError = exec.ExitError
)
func relError(file, path string) error {
return fmt.Errorf("%s resolves to executable relative to current directory (.%c%s)", file, filepath.Separator, path)
}
func LookPath(file string) (string, error) {
path, err := exec.LookPath(file)
if err != nil {
return "", err
}
if filepath.Base(file) == file && !filepath.IsAbs(path) {
return "", relError(file, path)
}
return path, nil
}
func fixCmd(name string, cmd *exec.Cmd) {
if filepath.Base(name) == name && !filepath.IsAbs(cmd.Path) {
// exec.Command was called with a bare binary name and
// exec.LookPath returned a path which is not absolute.
// Set cmd.lookPathErr and clear cmd.Path so that it
// cannot be run.
lookPathErr := (*error)(unsafe.Pointer(reflect.ValueOf(cmd).Elem().FieldByName("lookPathErr").Addr().Pointer()))
if *lookPathErr == nil {
*lookPathErr = relError(name, cmd.Path)
}
cmd.Path = ""
}
}
func CommandContext(ctx context.Context, name string, arg ...string) *exec.Cmd {
cmd := exec.CommandContext(ctx, name, arg...)
fixCmd(name, cmd)
return cmd
}
func Command(name string, arg ...string) *exec.Cmd {
cmd := exec.Command(name, arg...)
fixCmd(name, cmd)
return cmd
}