Official Go implementation of the Ethereum protocol
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go-ethereum/cmd/geth/dbcmd.go

762 lines
22 KiB

// Copyright 2021 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
package main
import (
"bytes"
"fmt"
"os"
"os/signal"
"path/filepath"
"strconv"
"strings"
"syscall"
"time"
"github.com/ethereum/go-ethereum/cmd/utils"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/console/prompt"
"github.com/ethereum/go-ethereum/core/rawdb"
"github.com/ethereum/go-ethereum/core/state/snapshot"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/internal/flags"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/trie"
"github.com/olekukonko/tablewriter"
"github.com/urfave/cli/v2"
)
var (
removeStateDataFlag = &cli.BoolFlag{
Name: "remove.state",
Usage: "If set, selects the state data for removal",
}
removeChainDataFlag = &cli.BoolFlag{
Name: "remove.chain",
Usage: "If set, selects the state data for removal",
}
removedbCommand = &cli.Command{
Action: removeDB,
Name: "removedb",
Usage: "Remove blockchain and state databases",
ArgsUsage: "",
Flags: flags.Merge(utils.DatabaseFlags,
[]cli.Flag{removeStateDataFlag, removeChainDataFlag}),
Description: `
Remove blockchain and state databases`,
}
dbCommand = &cli.Command{
Name: "db",
Usage: "Low level database operations",
ArgsUsage: "",
Subcommands: []*cli.Command{
dbInspectCmd,
dbStatCmd,
dbCompactCmd,
dbGetCmd,
dbDeleteCmd,
dbPutCmd,
dbGetSlotsCmd,
dbDumpFreezerIndex,
dbImportCmd,
dbExportCmd,
dbMetadataCmd,
dbCheckStateContentCmd,
},
}
dbInspectCmd = &cli.Command{
Action: inspect,
Name: "inspect",
ArgsUsage: "<prefix> <start>",
Flags: flags.Merge([]cli.Flag{
utils.SyncModeFlag,
}, utils.NetworkFlags, utils.DatabaseFlags),
Usage: "Inspect the storage size for each type of data in the database",
Description: `This commands iterates the entire database. If the optional 'prefix' and 'start' arguments are provided, then the iteration is limited to the given subset of data.`,
}
dbCheckStateContentCmd = &cli.Command{
Action: checkStateContent,
Name: "check-state-content",
ArgsUsage: "<start (optional)>",
Flags: flags.Merge(utils.NetworkFlags, utils.DatabaseFlags),
Usage: "Verify that state data is cryptographically correct",
Description: `This command iterates the entire database for 32-byte keys, looking for rlp-encoded trie nodes.
For each trie node encountered, it checks that the key corresponds to the keccak256(value). If this is not true, this indicates
a data corruption.`,
}
dbStatCmd = &cli.Command{
Action: dbStats,
Name: "stats",
Usage: "Print leveldb statistics",
Flags: flags.Merge([]cli.Flag{
utils.SyncModeFlag,
}, utils.NetworkFlags, utils.DatabaseFlags),
}
dbCompactCmd = &cli.Command{
Action: dbCompact,
Name: "compact",
Usage: "Compact leveldb database. WARNING: May take a very long time",
Flags: flags.Merge([]cli.Flag{
utils.SyncModeFlag,
utils.CacheFlag,
utils.CacheDatabaseFlag,
}, utils.NetworkFlags, utils.DatabaseFlags),
Description: `This command performs a database compaction.
WARNING: This operation may take a very long time to finish, and may cause database
corruption if it is aborted during execution'!`,
}
dbGetCmd = &cli.Command{
Action: dbGet,
Name: "get",
Usage: "Show the value of a database key",
ArgsUsage: "<hex-encoded key>",
Flags: flags.Merge([]cli.Flag{
utils.SyncModeFlag,
}, utils.NetworkFlags, utils.DatabaseFlags),
Description: "This command looks up the specified database key from the database.",
}
dbDeleteCmd = &cli.Command{
Action: dbDelete,
Name: "delete",
Usage: "Delete a database key (WARNING: may corrupt your database)",
ArgsUsage: "<hex-encoded key>",
Flags: flags.Merge([]cli.Flag{
utils.SyncModeFlag,
}, utils.NetworkFlags, utils.DatabaseFlags),
Description: `This command deletes the specified database key from the database.
WARNING: This is a low-level operation which may cause database corruption!`,
}
dbPutCmd = &cli.Command{
Action: dbPut,
Name: "put",
Usage: "Set the value of a database key (WARNING: may corrupt your database)",
ArgsUsage: "<hex-encoded key> <hex-encoded value>",
Flags: flags.Merge([]cli.Flag{
utils.SyncModeFlag,
}, utils.NetworkFlags, utils.DatabaseFlags),
Description: `This command sets a given database key to the given value.
WARNING: This is a low-level operation which may cause database corruption!`,
}
dbGetSlotsCmd = &cli.Command{
Action: dbDumpTrie,
Name: "dumptrie",
Usage: "Show the storage key/values of a given storage trie",
ArgsUsage: "<hex-encoded state root> <hex-encoded account hash> <hex-encoded storage trie root> <hex-encoded start (optional)> <int max elements (optional)>",
Flags: flags.Merge([]cli.Flag{
utils.SyncModeFlag,
}, utils.NetworkFlags, utils.DatabaseFlags),
Description: "This command looks up the specified database key from the database.",
}
dbDumpFreezerIndex = &cli.Command{
Action: freezerInspect,
Name: "freezer-index",
Usage: "Dump out the index of a specific freezer table",
ArgsUsage: "<freezer-type> <table-type> <start (int)> <end (int)>",
Flags: flags.Merge([]cli.Flag{
utils.SyncModeFlag,
}, utils.NetworkFlags, utils.DatabaseFlags),
Description: "This command displays information about the freezer index.",
}
dbImportCmd = &cli.Command{
Action: importLDBdata,
Name: "import",
Usage: "Imports leveldb-data from an exported RLP dump.",
ArgsUsage: "<dumpfile> <start (optional)",
Flags: flags.Merge([]cli.Flag{
utils.SyncModeFlag,
}, utils.NetworkFlags, utils.DatabaseFlags),
Description: "The import command imports the specific chain data from an RLP encoded stream.",
}
dbExportCmd = &cli.Command{
Action: exportChaindata,
Name: "export",
Usage: "Exports the chain data into an RLP dump. If the <dumpfile> has .gz suffix, gzip compression will be used.",
ArgsUsage: "<type> <dumpfile>",
Flags: flags.Merge([]cli.Flag{
utils.SyncModeFlag,
}, utils.NetworkFlags, utils.DatabaseFlags),
Description: "Exports the specified chain data to an RLP encoded stream, optionally gzip-compressed.",
}
dbMetadataCmd = &cli.Command{
Action: showMetaData,
Name: "metadata",
Usage: "Shows metadata about the chain status.",
Flags: flags.Merge([]cli.Flag{
utils.SyncModeFlag,
}, utils.NetworkFlags, utils.DatabaseFlags),
Description: "Shows metadata about the chain status.",
}
)
func removeDB(ctx *cli.Context) error {
stack, config := makeConfigNode(ctx)
// Resolve folder paths.
var (
rootDir = stack.ResolvePath("chaindata")
ancientDir = config.Eth.DatabaseFreezer
)
switch {
case ancientDir == "":
ancientDir = filepath.Join(stack.ResolvePath("chaindata"), "ancient")
case !filepath.IsAbs(ancientDir):
ancientDir = config.Node.ResolvePath(ancientDir)
}
// Delete state data
statePaths := []string{rootDir, filepath.Join(ancientDir, rawdb.StateFreezerName)}
confirmAndRemoveDB(statePaths, "state data", ctx, removeStateDataFlag.Name)
// Delete ancient chain
chainPaths := []string{filepath.Join(ancientDir, rawdb.ChainFreezerName)}
confirmAndRemoveDB(chainPaths, "ancient chain", ctx, removeChainDataFlag.Name)
return nil
}
// removeFolder deletes all files (not folders) inside the directory 'dir' (but
// not files in subfolders).
func removeFolder(dir string) {
filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
// If we're at the top level folder, recurse into
if path == dir {
return nil
}
// Delete all the files, but not subfolders
if !info.IsDir() {
os.Remove(path)
return nil
}
return filepath.SkipDir
})
}
// confirmAndRemoveDB prompts the user for a last confirmation and removes the
// list of folders if accepted.
func confirmAndRemoveDB(paths []string, kind string, ctx *cli.Context, removeFlagName string) {
var (
confirm bool
err error
)
msg := fmt.Sprintf("Location(s) of '%s': \n", kind)
for _, path := range paths {
msg += fmt.Sprintf("\t- %s\n", path)
}
fmt.Println(msg)
if ctx.IsSet(removeFlagName) {
confirm = ctx.Bool(removeFlagName)
if confirm {
fmt.Printf("Remove '%s'? [y/n] y\n", kind)
} else {
fmt.Printf("Remove '%s'? [y/n] n\n", kind)
}
} else {
confirm, err = prompt.Stdin.PromptConfirm(fmt.Sprintf("Remove '%s'?", kind))
}
switch {
case err != nil:
utils.Fatalf("%v", err)
case !confirm:
log.Info("Database deletion skipped", "kind", kind, "paths", paths)
default:
var (
deleted []string
start = time.Now()
)
for _, path := range paths {
if common.FileExist(path) {
removeFolder(path)
deleted = append(deleted, path)
} else {
log.Info("Folder is not existent", "path", path)
}
}
log.Info("Database successfully deleted", "kind", kind, "paths", deleted, "elapsed", common.PrettyDuration(time.Since(start)))
}
}
func inspect(ctx *cli.Context) error {
var (
prefix []byte
start []byte
)
if ctx.NArg() > 2 {
return fmt.Errorf("max 2 arguments: %v", ctx.Command.ArgsUsage)
}
if ctx.NArg() >= 1 {
if d, err := hexutil.Decode(ctx.Args().Get(0)); err != nil {
return fmt.Errorf("failed to hex-decode 'prefix': %v", err)
} else {
prefix = d
}
}
if ctx.NArg() >= 2 {
if d, err := hexutil.Decode(ctx.Args().Get(1)); err != nil {
return fmt.Errorf("failed to hex-decode 'start': %v", err)
} else {
start = d
}
}
stack, _ := makeConfigNode(ctx)
defer stack.Close()
db := utils.MakeChainDatabase(ctx, stack, true)
defer db.Close()
return rawdb.InspectDatabase(db, prefix, start)
}
func checkStateContent(ctx *cli.Context) error {
var (
prefix []byte
start []byte
)
if ctx.NArg() > 1 {
return fmt.Errorf("max 1 argument: %v", ctx.Command.ArgsUsage)
}
if ctx.NArg() > 0 {
if d, err := hexutil.Decode(ctx.Args().First()); err != nil {
return fmt.Errorf("failed to hex-decode 'start': %v", err)
} else {
start = d
}
}
stack, _ := makeConfigNode(ctx)
defer stack.Close()
db := utils.MakeChainDatabase(ctx, stack, true)
defer db.Close()
var (
it = rawdb.NewKeyLengthIterator(db.NewIterator(prefix, start), 32)
hasher = crypto.NewKeccakState()
got = make([]byte, 32)
errs int
count int
startTime = time.Now()
lastLog = time.Now()
)
for it.Next() {
count++
k := it.Key()
v := it.Value()
hasher.Reset()
hasher.Write(v)
hasher.Read(got)
if !bytes.Equal(k, got) {
errs++
fmt.Printf("Error at %#x\n", k)
fmt.Printf(" Hash: %#x\n", got)
fmt.Printf(" Data: %#x\n", v)
}
if time.Since(lastLog) > 8*time.Second {
log.Info("Iterating the database", "at", fmt.Sprintf("%#x", k), "elapsed", common.PrettyDuration(time.Since(startTime)))
lastLog = time.Now()
}
}
if err := it.Error(); err != nil {
return err
}
log.Info("Iterated the state content", "errors", errs, "items", count)
return nil
}
func showLeveldbStats(db ethdb.KeyValueStater) {
if stats, err := db.Stat("leveldb.stats"); err != nil {
log.Warn("Failed to read database stats", "error", err)
} else {
fmt.Println(stats)
}
if ioStats, err := db.Stat("leveldb.iostats"); err != nil {
log.Warn("Failed to read database iostats", "error", err)
} else {
fmt.Println(ioStats)
}
}
func dbStats(ctx *cli.Context) error {
stack, _ := makeConfigNode(ctx)
defer stack.Close()
db := utils.MakeChainDatabase(ctx, stack, true)
defer db.Close()
showLeveldbStats(db)
return nil
}
func dbCompact(ctx *cli.Context) error {
stack, _ := makeConfigNode(ctx)
defer stack.Close()
db := utils.MakeChainDatabase(ctx, stack, false)
defer db.Close()
log.Info("Stats before compaction")
showLeveldbStats(db)
log.Info("Triggering compaction")
if err := db.Compact(nil, nil); err != nil {
log.Info("Compact err", "error", err)
return err
}
log.Info("Stats after compaction")
showLeveldbStats(db)
return nil
}
// dbGet shows the value of a given database key
func dbGet(ctx *cli.Context) error {
if ctx.NArg() != 1 {
return fmt.Errorf("required arguments: %v", ctx.Command.ArgsUsage)
}
stack, _ := makeConfigNode(ctx)
defer stack.Close()
db := utils.MakeChainDatabase(ctx, stack, true)
defer db.Close()
key, err := common.ParseHexOrString(ctx.Args().Get(0))
if err != nil {
log.Info("Could not decode the key", "error", err)
return err
}
data, err := db.Get(key)
if err != nil {
log.Info("Get operation failed", "key", fmt.Sprintf("%#x", key), "error", err)
return err
}
fmt.Printf("key %#x: %#x\n", key, data)
return nil
}
// dbDelete deletes a key from the database
func dbDelete(ctx *cli.Context) error {
if ctx.NArg() != 1 {
return fmt.Errorf("required arguments: %v", ctx.Command.ArgsUsage)
}
stack, _ := makeConfigNode(ctx)
defer stack.Close()
db := utils.MakeChainDatabase(ctx, stack, false)
defer db.Close()
key, err := common.ParseHexOrString(ctx.Args().Get(0))
if err != nil {
log.Info("Could not decode the key", "error", err)
return err
}
data, err := db.Get(key)
if err == nil {
fmt.Printf("Previous value: %#x\n", data)
}
if err = db.Delete(key); err != nil {
log.Info("Delete operation returned an error", "key", fmt.Sprintf("%#x", key), "error", err)
return err
}
return nil
}
// dbPut overwrite a value in the database
func dbPut(ctx *cli.Context) error {
if ctx.NArg() != 2 {
return fmt.Errorf("required arguments: %v", ctx.Command.ArgsUsage)
}
stack, _ := makeConfigNode(ctx)
defer stack.Close()
db := utils.MakeChainDatabase(ctx, stack, false)
defer db.Close()
var (
key []byte
value []byte
data []byte
err error
)
key, err = common.ParseHexOrString(ctx.Args().Get(0))
if err != nil {
log.Info("Could not decode the key", "error", err)
return err
}
value, err = hexutil.Decode(ctx.Args().Get(1))
if err != nil {
log.Info("Could not decode the value", "error", err)
return err
}
data, err = db.Get(key)
if err == nil {
fmt.Printf("Previous value: %#x\n", data)
}
return db.Put(key, value)
}
// dbDumpTrie shows the key-value slots of a given storage trie
func dbDumpTrie(ctx *cli.Context) error {
if ctx.NArg() < 3 {
return fmt.Errorf("required arguments: %v", ctx.Command.ArgsUsage)
}
stack, _ := makeConfigNode(ctx)
defer stack.Close()
db := utils.MakeChainDatabase(ctx, stack, true)
defer db.Close()
triedb := utils.MakeTrieDatabase(ctx, db, false, true, false)
defer triedb.Close()
var (
state []byte
storage []byte
account []byte
start []byte
max = int64(-1)
err error
)
if state, err = hexutil.Decode(ctx.Args().Get(0)); err != nil {
log.Info("Could not decode the state root", "error", err)
return err
}
if account, err = hexutil.Decode(ctx.Args().Get(1)); err != nil {
log.Info("Could not decode the account hash", "error", err)
return err
}
if storage, err = hexutil.Decode(ctx.Args().Get(2)); err != nil {
log.Info("Could not decode the storage trie root", "error", err)
return err
}
if ctx.NArg() > 3 {
if start, err = hexutil.Decode(ctx.Args().Get(3)); err != nil {
log.Info("Could not decode the seek position", "error", err)
return err
}
}
if ctx.NArg() > 4 {
if max, err = strconv.ParseInt(ctx.Args().Get(4), 10, 64); err != nil {
log.Info("Could not decode the max count", "error", err)
return err
}
}
id := trie.StorageTrieID(common.BytesToHash(state), common.BytesToHash(account), common.BytesToHash(storage))
theTrie, err := trie.New(id, triedb)
if err != nil {
return err
}
trieIt, err := theTrie.NodeIterator(start)
if err != nil {
return err
}
var count int64
it := trie.NewIterator(trieIt)
for it.Next() {
if max > 0 && count == max {
fmt.Printf("Exiting after %d values\n", count)
break
}
fmt.Printf(" %d. key %#x: %#x\n", count, it.Key, it.Value)
count++
}
return it.Err
}
func freezerInspect(ctx *cli.Context) error {
if ctx.NArg() < 4 {
return fmt.Errorf("required arguments: %v", ctx.Command.ArgsUsage)
}
var (
freezer = ctx.Args().Get(0)
table = ctx.Args().Get(1)
)
start, err := strconv.ParseInt(ctx.Args().Get(2), 10, 64)
if err != nil {
log.Info("Could not read start-param", "err", err)
return err
}
end, err := strconv.ParseInt(ctx.Args().Get(3), 10, 64)
if err != nil {
log.Info("Could not read count param", "err", err)
return err
}
stack, _ := makeConfigNode(ctx)
ancient := stack.ResolveAncient("chaindata", ctx.String(utils.AncientFlag.Name))
stack.Close()
return rawdb.InspectFreezerTable(ancient, freezer, table, start, end)
}
func importLDBdata(ctx *cli.Context) error {
start := 0
switch ctx.NArg() {
case 1:
break
case 2:
s, err := strconv.Atoi(ctx.Args().Get(1))
if err != nil {
return fmt.Errorf("second arg must be an integer: %v", err)
}
start = s
default:
return fmt.Errorf("required arguments: %v", ctx.Command.ArgsUsage)
}
var (
fName = ctx.Args().Get(0)
stack, _ = makeConfigNode(ctx)
interrupt = make(chan os.Signal, 1)
stop = make(chan struct{})
)
defer stack.Close()
signal.Notify(interrupt, syscall.SIGINT, syscall.SIGTERM)
defer signal.Stop(interrupt)
defer close(interrupt)
go func() {
if _, ok := <-interrupt; ok {
log.Info("Interrupted during ldb import, stopping at next batch")
}
close(stop)
}()
db := utils.MakeChainDatabase(ctx, stack, false)
defer db.Close()
return utils.ImportLDBData(db, fName, int64(start), stop)
}
type preimageIterator struct {
iter ethdb.Iterator
}
func (iter *preimageIterator) Next() (byte, []byte, []byte, bool) {
for iter.iter.Next() {
key := iter.iter.Key()
if bytes.HasPrefix(key, rawdb.PreimagePrefix) && len(key) == (len(rawdb.PreimagePrefix)+common.HashLength) {
return utils.OpBatchAdd, key, iter.iter.Value(), true
}
}
return 0, nil, nil, false
}
func (iter *preimageIterator) Release() {
iter.iter.Release()
}
type snapshotIterator struct {
init bool
account ethdb.Iterator
storage ethdb.Iterator
}
func (iter *snapshotIterator) Next() (byte, []byte, []byte, bool) {
if !iter.init {
iter.init = true
return utils.OpBatchDel, rawdb.SnapshotRootKey, nil, true
}
for iter.account.Next() {
key := iter.account.Key()
if bytes.HasPrefix(key, rawdb.SnapshotAccountPrefix) && len(key) == (len(rawdb.SnapshotAccountPrefix)+common.HashLength) {
return utils.OpBatchAdd, key, iter.account.Value(), true
}
}
for iter.storage.Next() {
key := iter.storage.Key()
if bytes.HasPrefix(key, rawdb.SnapshotStoragePrefix) && len(key) == (len(rawdb.SnapshotStoragePrefix)+2*common.HashLength) {
return utils.OpBatchAdd, key, iter.storage.Value(), true
}
}
return 0, nil, nil, false
}
func (iter *snapshotIterator) Release() {
iter.account.Release()
iter.storage.Release()
}
// chainExporters defines the export scheme for all exportable chain data.
var chainExporters = map[string]func(db ethdb.Database) utils.ChainDataIterator{
"preimage": func(db ethdb.Database) utils.ChainDataIterator {
iter := db.NewIterator(rawdb.PreimagePrefix, nil)
return &preimageIterator{iter: iter}
},
"snapshot": func(db ethdb.Database) utils.ChainDataIterator {
account := db.NewIterator(rawdb.SnapshotAccountPrefix, nil)
storage := db.NewIterator(rawdb.SnapshotStoragePrefix, nil)
return &snapshotIterator{account: account, storage: storage}
},
}
func exportChaindata(ctx *cli.Context) error {
if ctx.NArg() < 2 {
return fmt.Errorf("required arguments: %v", ctx.Command.ArgsUsage)
}
// Parse the required chain data type, make sure it's supported.
kind := ctx.Args().Get(0)
kind = strings.ToLower(strings.Trim(kind, " "))
exporter, ok := chainExporters[kind]
if !ok {
var kinds []string
for kind := range chainExporters {
kinds = append(kinds, kind)
}
return fmt.Errorf("invalid data type %s, supported types: %s", kind, strings.Join(kinds, ", "))
}
var (
stack, _ = makeConfigNode(ctx)
interrupt = make(chan os.Signal, 1)
stop = make(chan struct{})
)
defer stack.Close()
signal.Notify(interrupt, syscall.SIGINT, syscall.SIGTERM)
defer signal.Stop(interrupt)
defer close(interrupt)
go func() {
if _, ok := <-interrupt; ok {
log.Info("Interrupted during db export, stopping at next batch")
}
close(stop)
}()
db := utils.MakeChainDatabase(ctx, stack, true)
defer db.Close()
return utils.ExportChaindata(ctx.Args().Get(1), kind, exporter(db), stop)
}
func showMetaData(ctx *cli.Context) error {
stack, _ := makeConfigNode(ctx)
defer stack.Close()
db := utils.MakeChainDatabase(ctx, stack, true)
defer db.Close()
ancients, err := db.Ancients()
if err != nil {
fmt.Fprintf(os.Stderr, "Error accessing ancients: %v", err)
}
data := rawdb.ReadChainMetadata(db)
data = append(data, []string{"frozen", fmt.Sprintf("%d items", ancients)})
data = append(data, []string{"snapshotGenerator", snapshot.ParseGeneratorStatus(rawdb.ReadSnapshotGenerator(db))})
if b := rawdb.ReadHeadBlock(db); b != nil {
data = append(data, []string{"headBlock.Hash", fmt.Sprintf("%v", b.Hash())})
data = append(data, []string{"headBlock.Root", fmt.Sprintf("%v", b.Root())})
data = append(data, []string{"headBlock.Number", fmt.Sprintf("%d (%#x)", b.Number(), b.Number())})
}
if h := rawdb.ReadHeadHeader(db); h != nil {
data = append(data, []string{"headHeader.Hash", fmt.Sprintf("%v", h.Hash())})
data = append(data, []string{"headHeader.Root", fmt.Sprintf("%v", h.Root)})
data = append(data, []string{"headHeader.Number", fmt.Sprintf("%d (%#x)", h.Number, h.Number)})
}
table := tablewriter.NewWriter(os.Stdout)
table.SetHeader([]string{"Field", "Value"})
table.AppendBulk(data)
table.Render()
return nil
}