func getSysctrlEnv(env []string) []string {
	foundLC := false
	for i, line := range env {
		if strings.HasPrefix(line, "LC_ALL") {
			env[i] = "LC_ALL=C"
			foundLC = true
		}
	}
	if !foundLC {
		env = append(env, "LC_ALL=C")
	}
	return env
}
getSysctrlEnv sets LC_ALL=C in a list of env vars for use when running
sysctl commands (see DoSysctrl).
package common
import (
	"bufio"
	"bytes"
	"context"
	"errors"
	"fmt"
	"io/ioutil"
	"net/url"
	"os"
	"os/exec"
	"path"
	"path/filepath"
	"reflect"
	"runtime"
	"strconv"
	"strings"
	"time"
)
var (
	Timeout    = 3 * time.Second
	ErrTimeout = errors.New("command timed out")
)
type Invoker interface {
	Command(string, ...string) ([]byte, error)
	CommandWithContext(context.Context, string, ...string) ([]byte, error)
}
type Invoke struct{}
func (i Invoke) Command(name string, arg ...string) ([]byte, error) {
	ctx, cancel := context.WithTimeout(context.Background(), Timeout)
	defer cancel()
	return i.CommandWithContext(ctx, name, arg...)
}
func (i Invoke) CommandWithContext(ctx context.Context, name string, arg ...string) ([]byte, error) {
	cmd := exec.CommandContext(ctx, name, arg...)
	var buf bytes.Buffer
	cmd.Stdout = &buf
	cmd.Stderr = &buf
	if err := cmd.Start(); err != nil {
		return buf.Bytes(), err
	}
	if err := cmd.Wait(); err != nil {
		return buf.Bytes(), err
	}
	return buf.Bytes(), nil
}
type FakeInvoke struct {
	Suffix string  
	Error  error   
}
func (i FakeInvoke) Command(name string, arg ...string) ([]byte, error) {
	if i.Error != nil {
		return []byte{}, i.Error
	}
	arch := runtime.GOOS
	commandName := filepath.Base(name)
	fname := strings.Join(append([]string{commandName}, arg...), "")
	fname = url.QueryEscape(fname)
	fpath := path.Join("testdata", arch, fname)
	if i.Suffix != "" {
		fpath += "_" + i.Suffix
	}
	if PathExists(fpath) {
		return ioutil.ReadFile(fpath)
	}
	return []byte{}, fmt.Errorf("could not find testdata: %s", fpath)
}
func (i FakeInvoke) CommandWithContext(ctx context.Context, name string, arg ...string) ([]byte, error) {
	return i.Command(name, arg...)
}
var ErrNotImplementedError = errors.New("not implemented yet")
func ReadFile(filename string) (string, error) {
	content, err := ioutil.ReadFile(filename)
	if err != nil {
		return "", err
	}
	return string(content), nil
}
func ReadLines(filename string) ([]string, error) {
	return ReadLinesOffsetN(filename, 0, -1)
}
func ReadLinesOffsetN(filename string, offset uint, n int) ([]string, error) {
	f, err := os.Open(filename)
	if err != nil {
		return []string{""}, err
	}
	defer f.Close()
	var ret []string
	r := bufio.NewReader(f)
	for i := 0; i < n+int(offset) || n < 0; i++ {
		line, err := r.ReadString('\n')
		if err != nil {
			break
		}
		if i < int(offset) {
			continue
		}
		ret = append(ret, strings.Trim(line, "\n"))
	}
	return ret, nil
}
func IntToString(orig []int8) string {
	ret := make([]byte, len(orig))
	size := -1
	for i, o := range orig {
		if o == 0 {
			size = i
			break
		}
		ret[i] = byte(o)
	}
	if size == -1 {
		size = len(orig)
	}
	return string(ret[0:size])
}
func UintToString(orig []uint8) string {
	ret := make([]byte, len(orig))
	size := -1
	for i, o := range orig {
		if o == 0 {
			size = i
			break
		}
		ret[i] = byte(o)
	}
	if size == -1 {
		size = len(orig)
	}
	return string(ret[0:size])
}
func ByteToString(orig []byte) string {
	n := -1
	l := -1
	for i, b := range orig {
		if l == -1 && b == 0 {
			continue
		}
		if l == -1 {
			l = i
		}
		if b == 0 {
			break
		}
		n = i + 1
	}
	if n == -1 {
		return string(orig)
	}
	return string(orig[l:n])
}
func ReadInts(filename string) ([]int64, error) {
	f, err := os.Open(filename)
	if err != nil {
		return []int64{}, err
	}
	defer f.Close()
	var ret []int64
	r := bufio.NewReader(f)
	line, err := r.ReadString('\n')
	if err != nil {
		return []int64{}, err
	}
	i, err := strconv.ParseInt(strings.Trim(line, "\n"), 10, 32)
	if err != nil {
		return []int64{}, err
	}
	ret = append(ret, i)
	return ret, nil
}
func HexToUint32(hex string) uint32 {
	vv, _ := strconv.ParseUint(hex, 16, 32)
	return uint32(vv)
}
func mustParseInt32(val string) int32 {
	vv, _ := strconv.ParseInt(val, 10, 32)
	return int32(vv)
}
func mustParseUint64(val string) uint64 {
	vv, _ := strconv.ParseInt(val, 10, 64)
	return uint64(vv)
}
func mustParseFloat64(val string) float64 {
	vv, _ := strconv.ParseFloat(val, 64)
	return vv
}
func StringsHas(target []string, src string) bool {
	for _, t := range target {
		if strings.TrimSpace(t) == src {
			return true
		}
	}
	return false
}
func StringsContains(target []string, src string) bool {
	for _, t := range target {
		if strings.Contains(t, src) {
			return true
		}
	}
	return false
}
func IntContains(target []int, src int) bool {
	for _, t := range target {
		if src == t {
			return true
		}
	}
	return false
}
func attributes(m interface{}) map[string]reflect.Type {
	typ := reflect.TypeOf(m)
	if typ.Kind() == reflect.Ptr {
		typ = typ.Elem()
	}
	attrs := make(map[string]reflect.Type)
	if typ.Kind() != reflect.Struct {
		return nil
	}
	for i := 0; i < typ.NumField(); i++ {
		p := typ.Field(i)
		if !p.Anonymous {
			attrs[p.Name] = p.Type
		}
	}
	return attrs
}
func PathExists(filename string) bool {
	if _, err := os.Stat(filename); err == nil {
		return true
	}
	return false
}
func GetEnv(key string, dfault string, combineWith ...string) string {
	value := os.Getenv(key)
	if value == "" {
		value = dfault
	}
	switch len(combineWith) {
	case 0:
		return value
	case 1:
		return filepath.Join(value, combineWith[0])
	default:
		all := make([]string, len(combineWith)+1)
		all[0] = value
		copy(all[1:], combineWith)
		return filepath.Join(all...)
	}
}
func HostProc(combineWith ...string) string {
	return GetEnv("HOST_PROC", "/proc", combineWith...)
}
func HostSys(combineWith ...string) string {
	return GetEnv("HOST_SYS", "/sys", combineWith...)
}
func HostEtc(combineWith ...string) string {
	return GetEnv("HOST_ETC", "/etc", combineWith...)
}
func HostVar(combineWith ...string) string {
	return GetEnv("HOST_VAR", "/var", combineWith...)
}
func HostRun(combineWith ...string) string {
	return GetEnv("HOST_RUN", "/run", combineWith...)
}
func HostDev(combineWith ...string) string {
	return GetEnv("HOST_DEV", "/dev", combineWith...)
}