aboutsummaryrefslogtreecommitdiffstats
path: root/cmd/geth/main.go
blob: 37cf3451a195c7b2388fdddbc2abf816c8b741dc (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
// Copyright 2014 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/>.

// geth is the official command-line client for Ethereum.
package main

import (
    "fmt"
    "io/ioutil"
    "os"
    "path/filepath"
    "runtime"
    "strconv"
    "strings"
    "time"

    "github.com/codegangsta/cli"
    "github.com/ethereum/ethash"
    "github.com/ethereum/go-ethereum/accounts"
    "github.com/ethereum/go-ethereum/cmd/utils"
    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/core"
    "github.com/ethereum/go-ethereum/eth"
    "github.com/ethereum/go-ethereum/ethdb"
    "github.com/ethereum/go-ethereum/internal/debug"
    "github.com/ethereum/go-ethereum/logger"
    "github.com/ethereum/go-ethereum/logger/glog"
    "github.com/ethereum/go-ethereum/metrics"
    "github.com/ethereum/go-ethereum/node"
    "github.com/ethereum/go-ethereum/params"
    "github.com/ethereum/go-ethereum/rlp"
)

const (
    ClientIdentifier = "Geth"
    Version          = "1.4.0-unstable"
    VersionMajor     = 1
    VersionMinor     = 4
    VersionPatch     = 0
)

var (
    gitCommit       string // set via linker flagg
    nodeNameVersion string
    app             *cli.App
)

func init() {
    if gitCommit == "" {
        nodeNameVersion = Version
    } else {
        nodeNameVersion = Version + "-" + gitCommit[:8]
    }

    app = utils.NewApp(Version, "the go-ethereum command line interface")
    app.Action = geth
    app.HideVersion = true // we have a command to print the version
    app.Commands = []cli.Command{
        importCommand,
        exportCommand,
        upgradedbCommand,
        removedbCommand,
        dumpCommand,
        monitorCommand,
        {
            Action: makedag,
            Name:   "makedag",
            Usage:  "generate ethash dag (for testing)",
            Description: `
The makedag command generates an ethash DAG in /tmp/dag.

This command exists to support the system testing project.
Regular users do not need to execute it.
`,
        },
        {
            Action: gpuinfo,
            Name:   "gpuinfo",
            Usage:  "gpuinfo",
            Description: `
Prints OpenCL device info for all found GPUs.
`,
        },
        {
            Action: gpubench,
            Name:   "gpubench",
            Usage:  "benchmark GPU",
            Description: `
Runs quick benchmark on first GPU found.
`,
        },
        {
            Action: version,
            Name:   "version",
            Usage:  "print ethereum version numbers",
            Description: `
The output of this command is supposed to be machine-readable.
`,
        },
        {
            Name:  "wallet",
            Usage: "ethereum presale wallet",
            Subcommands: []cli.Command{
                {
                    Action: importWallet,
                    Name:   "import",
                    Usage:  "import ethereum presale wallet",
                },
            },
            Description: `

    get wallet import /path/to/my/presale.wallet

will prompt for your password and imports your ether presale account.
It can be used non-interactively with the --password option taking a
passwordfile as argument containing the wallet password in plaintext.

`},
        {
            Action: accountList,
            Name:   "account",
            Usage:  "manage accounts",
            Description: `

Manage accounts lets you create new accounts, list all existing accounts,
import a private key into a new account.

'            help' shows a list of subcommands or help for one subcommand.

It supports interactive mode, when you are prompted for password as well as
non-interactive mode where passwords are supplied via a given password file.
Non-interactive mode is only meant for scripted use on test networks or known
safe environments.

Make sure you remember the password you gave when creating a new account (with
either new or import). Without it you are not able to unlock your account.

Note that exporting your key in unencrypted format is NOT supported.

Keys are stored under <DATADIR>/keys.
It is safe to transfer the entire directory or the individual keys therein
between ethereum nodes by simply copying.
Make sure you backup your keys regularly.

In order to use your account to send transactions, you need to unlock them using
the '--unlock' option. The argument is a space separated list of addresses or
indexes. If used non-interactively with a passwordfile, the file should contain
the respective passwords one per line. If you unlock n accounts and the password
file contains less than n entries, then the last password is meant to apply to
all remaining accounts.

And finally. DO NOT FORGET YOUR PASSWORD.
`,
            Subcommands: []cli.Command{
                {
                    Action: accountList,
                    Name:   "list",
                    Usage:  "print account addresses",
                },
                {
                    Action: accountCreate,
                    Name:   "new",
                    Usage:  "create a new account",
                    Description: `

    ethereum account new

Creates a new account. Prints the address.

The account is saved in encrypted format, you are prompted for a passphrase.

You must remember this passphrase to unlock your account in the future.

For non-interactive use the passphrase can be specified with the --password flag:

    ethereum --password <passwordfile> account new

Note, this is meant to be used for testing only, it is a bad idea to save your
password to file or expose in any other way.
                    `,
                },
                {
                    Action: accountUpdate,
                    Name:   "update",
                    Usage:  "update an existing account",
                    Description: `

    ethereum account update <address>

Update an existing account.

The account is saved in the newest version in encrypted format, you are prompted
for a passphrase to unlock the account and another to save the updated file.

This same command can therefore be used to migrate an account of a deprecated
format to the newest format or change the password for an account.

For non-interactive use the passphrase can be specified with the --password flag:

    ethereum --password <passwordfile> account update <address>

Since only one password can be given, only format update can be performed,
changing your password is only possible interactively.

Note that account update has the a side effect that the order of your accounts
changes.
                    `,
                },
                {
                    Action: accountImport,
                    Name:   "import",
                    Usage:  "import a private key into a new account",
                    Description: `

    ethereum account import <keyfile>

Imports an unencrypted private key from <keyfile> and creates a new account.
Prints the address.

The keyfile is assumed to contain an unencrypted private key in hexadecimal format.

The account is saved in encrypted format, you are prompted for a passphrase.

You must remember this passphrase to unlock your account in the future.

For non-interactive use the passphrase can be specified with the -password flag:

    ethereum --password <passwordfile> account import <keyfile>

Note:
As you can directly copy your encrypted accounts to another ethereum instance,
this import mechanism is not needed when you transfer an account between
nodes.
                    `,
                },
            },
        },
        {
            Action: initGenesis,
            Name:   "init",
            Usage:  "bootstraps and initialises a new genesis block (JSON)",
            Description: `
The init command initialises a new genesis block and definition for the network.
This is a destructive action and changes the network in which you will be
participating.
`,
        },
        {
            Action: console,
            Name:   "console",
            Usage:  `Geth Console: interactive JavaScript environment`,
            Description: `
The Geth console is an interactive shell for the JavaScript runtime environment
which exposes a node admin interface as well as the Ðapp JavaScript API.
See https://github.com/ethereum/go-ethereum/wiki/Javascipt-Console
`,
        },
        {
            Action: attach,
            Name:   "attach",
            Usage:  `Geth Console: interactive JavaScript environment (connect to node)`,
            Description: `
        The Geth console is an interactive shell for the JavaScript runtime environment
        which exposes a node admin interface as well as the Ðapp JavaScript API.
        See https://github.com/ethereum/go-ethereum/wiki/Javascipt-Console.
        This command allows to open a console on a running geth node.
        `,
        },
        {
            Action: execScripts,
            Name:   "js",
            Usage:  `executes the given JavaScript files in the Geth JavaScript VM`,
            Description: `
The JavaScript VM exposes a node admin interface as well as the Ðapp
JavaScript API. See https://github.com/ethereum/go-ethereum/wiki/Javascipt-Console
`,
        },
    }
    app.Flags = []cli.Flag{
        utils.IdentityFlag,
        utils.UnlockedAccountFlag,
        utils.PasswordFileFlag,
        utils.GenesisFileFlag,
        utils.BootnodesFlag,
        utils.DataDirFlag,
        utils.KeyStoreDirFlag,
        utils.BlockchainVersionFlag,
        utils.OlympicFlag,
        utils.FastSyncFlag,
        utils.CacheFlag,
        utils.LightKDFFlag,
        utils.JSpathFlag,
        utils.ListenPortFlag,
        utils.MaxPeersFlag,
        utils.MaxPendingPeersFlag,
        utils.EtherbaseFlag,
        utils.GasPriceFlag,
        utils.MinerThreadsFlag,
        utils.MiningEnabledFlag,
        utils.MiningGPUFlag,
        utils.AutoDAGFlag,
        utils.TargetGasLimitFlag,
        utils.NATFlag,
        utils.NatspecEnabledFlag,
        utils.NoDiscoverFlag,
        utils.NodeKeyFileFlag,
        utils.NodeKeyHexFlag,
        utils.RPCEnabledFlag,
        utils.RPCListenAddrFlag,
        utils.RPCPortFlag,
        utils.RPCApiFlag,
        utils.WSEnabledFlag,
        utils.WSListenAddrFlag,
        utils.WSPortFlag,
        utils.WSApiFlag,
        utils.WSAllowedOriginsFlag,
        utils.IPCDisabledFlag,
        utils.IPCApiFlag,
        utils.IPCPathFlag,
        utils.ExecFlag,
        utils.WhisperEnabledFlag,
        utils.DevModeFlag,
        utils.TestNetFlag,
        utils.VMForceJitFlag,
        utils.VMJitCacheFlag,
        utils.VMEnableJitFlag,
        utils.NetworkIdFlag,
        utils.RPCCORSDomainFlag,
        utils.MetricsEnabledFlag,
        utils.SolcPathFlag,
        utils.GpoMinGasPriceFlag,
        utils.GpoMaxGasPriceFlag,
        utils.GpoFullBlockRatioFlag,
        utils.GpobaseStepDownFlag,
        utils.GpobaseStepUpFlag,
        utils.GpobaseCorrectionFactorFlag,
        utils.ExtraDataFlag,
    }
    app.Flags = append(app.Flags, debug.Flags...)

    app.Before = func(ctx *cli.Context) error {
        runtime.GOMAXPROCS(runtime.NumCPU())
        if err := debug.Setup(ctx); err != nil {
            return err
        }
        // Start system runtime metrics collection
        go metrics.CollectProcessMetrics(3 * time.Second)

        utils.SetupNetwork(ctx)

        // Deprecation warning.
        if ctx.GlobalIsSet(utils.GenesisFileFlag.Name) {
            common.PrintDepricationWarning("--genesis is deprecated. Switch to use 'geth init /path/to/file'")
        }

        return nil
    }

    app.After = func(ctx *cli.Context) error {
        logger.Flush()
        debug.Exit()
        return nil
    }
}

func main() {
    if err := app.Run(os.Args); err != nil {
        fmt.Fprintln(os.Stderr, err)
        os.Exit(1)
    }
}

func makeDefaultExtra() []byte {
    var clientInfo = struct {
        Version   uint
        Name      string
        GoVersion string
        Os        string
    }{uint(VersionMajor<<16 | VersionMinor<<8 | VersionPatch), ClientIdentifier, runtime.Version(), runtime.GOOS}
    extra, err := rlp.EncodeToBytes(clientInfo)
    if err != nil {
        glog.V(logger.Warn).Infoln("error setting canonical miner information:", err)
    }

    if uint64(len(extra)) > params.MaximumExtraDataSize.Uint64() {
        glog.V(logger.Warn).Infoln("error setting canonical miner information: extra exceeds", params.MaximumExtraDataSize)
        glog.V(logger.Debug).Infof("extra: %x\n", extra)
        return nil
    }
    return extra
}

// geth is the main entry point into the system if no special subcommand is ran.
// It creates a default node based on the command line arguments and runs it in
// blocking mode, waiting for it to be shut down.
func geth(ctx *cli.Context) {
    node := utils.MakeSystemNode(ClientIdentifier, nodeNameVersion, makeDefaultExtra(), ctx)
    startNode(ctx, node)
    node.Wait()
}

// attach will connect to a running geth instance attaching a JavaScript console and to it.
func attach(ctx *cli.Context) {
    // attach to a running geth instance
    client, err := utils.NewRemoteRPCClient(ctx)
    if err != nil {
        utils.Fatalf("Unable to attach to geth: %v", err)
    }

    repl := newLightweightJSRE(
        ctx.GlobalString(utils.JSpathFlag.Name),
        client,
        ctx.GlobalString(utils.DataDirFlag.Name),
        true,
    )

    if ctx.GlobalString(utils.ExecFlag.Name) != "" {
        repl.batch(ctx.GlobalString(utils.ExecFlag.Name))
    } else {
        repl.welcome()
        repl.interactive()
    }
}

// initGenesis will initialise the given JSON format genesis file and writes it as
// the zero'd block (i.e. genesis) or will fail hard if it can't succeed.
func initGenesis(ctx *cli.Context) {
    genesisPath := ctx.Args().First()
    if len(genesisPath) == 0 {
        utils.Fatalf("must supply path to genesis JSON file")
    }

    chainDb, err := ethdb.NewLDBDatabase(filepath.Join(utils.MustMakeDataDir(ctx), "chaindata"), 0, 0)
    if err != nil {
        utils.Fatalf("could not open database: %v", err)
    }

    genesisFile, err := os.Open(genesisPath)
    if err != nil {
        utils.Fatalf("failed to read genesis file: %v", err)
    }

    block, err := core.WriteGenesisBlock(chainDb, genesisFile)
    if err != nil {
        utils.Fatalf("failed to write genesis block: %v", err)
    }
    glog.V(logger.Info).Infof("successfully wrote genesis block and/or chain rule set: %x", block.Hash())
}

// console starts a new geth node, attaching a JavaScript console to it at the
// same time.
func console(ctx *cli.Context) {
    // Create and start the node based on the CLI flags
    node := utils.MakeSystemNode(ClientIdentifier, nodeNameVersion, makeDefaultExtra(), ctx)
    startNode(ctx, node)

    // Attach to the newly started node, and either execute script or become interactive
    client, err := node.Attach()
    if err != nil {
        utils.Fatalf("Failed to attach to the inproc geth: %v", err)
    }
    repl := newJSRE(node,
        ctx.GlobalString(utils.JSpathFlag.Name),
        ctx.GlobalString(utils.RPCCORSDomainFlag.Name),
        client, true)

    if script := ctx.GlobalString(utils.ExecFlag.Name); script != "" {
        repl.batch(script)
    } else {
        repl.welcome()
        repl.interactive()
    }
    node.Stop()
}

// execScripts starts a new geth node based on the CLI flags, and executes each
// of the JavaScript files specified as command arguments.
func execScripts(ctx *cli.Context) {
    // Create and start the node based on the CLI flags
    node := utils.MakeSystemNode(ClientIdentifier, nodeNameVersion, makeDefaultExtra(), ctx)
    startNode(ctx, node)

    // Attach to the newly started node and execute the given scripts
    client, err := node.Attach()
    if err != nil {
        utils.Fatalf("Failed to attach to the inproc geth: %v", err)
    }
    repl := newJSRE(node,
        ctx.GlobalString(utils.JSpathFlag.Name),
        ctx.GlobalString(utils.RPCCORSDomainFlag.Name),
        client, false)

    for _, file := range ctx.Args() {
        repl.exec(file)
    }
    node.Stop()
}

// tries unlocking the specified account a few times.
func unlockAccount(ctx *cli.Context, accman *accounts.Manager, address string, i int, passwords []string) (common.Address, string) {
    account, err := utils.MakeAddress(accman, address)
    if err != nil {
        utils.Fatalf("Unlock error: %v", err)
    }

    for trials := 0; trials < 3; trials++ {
        prompt := fmt.Sprintf("Unlocking account %s | Attempt %d/%d", address, trials+1, 3)
        password := getPassPhrase(prompt, false, i, passwords)
        if err := accman.Unlock(account, password); err == nil {
            return account, password
        }
    }
    // All trials expended to unlock account, bail out
    utils.Fatalf("Failed to unlock account: %s", address)
    return common.Address{}, ""
}

// startNode boots up the system node and all registered protocols, after which
// it unlocks any requested accounts, and starts the RPC/IPC interfaces and the
// miner.
func startNode(ctx *cli.Context, stack *node.Node) {
    // Start up the node itself
    utils.StartNode(stack)

    // Unlock any account specifically requested
    var ethereum *eth.Ethereum
    if err := stack.Service(&ethereum); err != nil {
        utils.Fatalf("ethereum service not running: %v", err)
    }
    accman := ethereum.AccountManager()
    passwords := utils.MakePasswordList(ctx)

    accounts := strings.Split(ctx.GlobalString(utils.UnlockedAccountFlag.Name), ",")
    for i, account := range accounts {
        if trimmed := strings.TrimSpace(account); trimmed != "" {
            unlockAccount(ctx, accman, trimmed, i, passwords)
        }
    }
    // Start auxiliary services if enabled
    if ctx.GlobalBool(utils.MiningEnabledFlag.Name) {
        if err := ethereum.StartMining(ctx.GlobalInt(utils.MinerThreadsFlag.Name), ctx.GlobalString(utils.MiningGPUFlag.Name)); err != nil {
            utils.Fatalf("Failed to start mining: %v", err)
        }
    }
}

func accountList(ctx *cli.Context) {
    accman := utils.MakeAccountManager(ctx)
    accts, err := accman.Accounts()
    if err != nil {
        utils.Fatalf("Could not list accounts: %v", err)
    }
    for i, acct := range accts {
        fmt.Printf("Account #%d: %x\n", i, acct)
    }
}

// getPassPhrase retrieves the passwor associated with an account, either fetched
// from a list of preloaded passphrases, or requested interactively from the user.
func getPassPhrase(prompt string, confirmation bool, i int, passwords []string) string {
    // If a list of passwords was supplied, retrieve from them
    if len(passwords) > 0 {
        if i < len(passwords) {
            return passwords[i]
        }
        return passwords[len(passwords)-1]
    }
    // Otherwise prompt the user for the password
    fmt.Println(prompt)
    password, err := utils.PromptPassword("Passphrase: ", true)
    if err != nil {
        utils.Fatalf("Failed to read passphrase: %v", err)
    }
    if confirmation {
        confirm, err := utils.PromptPassword("Repeat passphrase: ", false)
        if err != nil {
            utils.Fatalf("Failed to read passphrase confirmation: %v", err)
        }
        if password != confirm {
            utils.Fatalf("Passphrases do not match")
        }
    }
    return password
}

// accountCreate creates a new account into the keystore defined by the CLI flags.
func accountCreate(ctx *cli.Context) {
    accman := utils.MakeAccountManager(ctx)
    password := getPassPhrase("Your new account is locked with a password. Please give a password. Do not forget this password.", true, 0, utils.MakePasswordList(ctx))

    account, err := accman.NewAccount(password)
    if err != nil {
        utils.Fatalf("Failed to create account: %v", err)
    }
    fmt.Printf("Address: %x\n", account)
}

// accountUpdate transitions an account from a previous format to the current
// one, also providing the possibility to change the pass-phrase.
func accountUpdate(ctx *cli.Context) {
    if len(ctx.Args()) == 0 {
        utils.Fatalf("No accounts specified to update")
    }
    accman := utils.MakeAccountManager(ctx)

    account, oldPassword := unlockAccount(ctx, accman, ctx.Args().First(), 0, nil)
    newPassword := getPassPhrase("Please give a new password. Do not forget this password.", true, 0, nil)
    if err := accman.Update(account, oldPassword, newPassword); err != nil {
        utils.Fatalf("Could not update the account: %v", err)
    }
}

func importWallet(ctx *cli.Context) {
    keyfile := ctx.Args().First()
    if len(keyfile) == 0 {
        utils.Fatalf("keyfile must be given as argument")
    }
    keyJson, err := ioutil.ReadFile(keyfile)
    if err != nil {
        utils.Fatalf("Could not read wallet file: %v", err)
    }

    accman := utils.MakeAccountManager(ctx)
    passphrase := getPassPhrase("", false, 0, utils.MakePasswordList(ctx))

    acct, err := accman.ImportPreSaleKey(keyJson, passphrase)
    if err != nil {
        utils.Fatalf("Could not create the account: %v", err)
    }
    fmt.Printf("Address: %x\n", acct)
}

func accountImport(ctx *cli.Context) {
    keyfile := ctx.Args().First()
    if len(keyfile) == 0 {
        utils.Fatalf("keyfile must be given as argument")
    }
    accman := utils.MakeAccountManager(ctx)
    passphrase := getPassPhrase("Your new account is locked with a password. Please give a password. Do not forget this password.", true, 0, utils.MakePasswordList(ctx))
    acct, err := accman.Import(keyfile, passphrase)
    if err != nil {
        utils.Fatalf("Could not create the account: %v", err)
    }
    fmt.Printf("Address: %x\n", acct)
}

func makedag(ctx *cli.Context) {
    args := ctx.Args()
    wrongArgs := func() {
        utils.Fatalf(`Usage: geth makedag <block number> <outputdir>`)
    }
    switch {
    case len(args) == 2:
        blockNum, err := strconv.ParseUint(args[0], 0, 64)
        dir := args[1]
        if err != nil {
            wrongArgs()
        } else {
            dir = filepath.Clean(dir)
            // seems to require a trailing slash
            if !strings.HasSuffix(dir, "/") {
                dir = dir + "/"
            }
            _, err = ioutil.ReadDir(dir)
            if err != nil {
                utils.Fatalf("Can't find dir")
            }
            fmt.Println("making DAG, this could take awhile...")
            ethash.MakeDAG(blockNum, dir)
        }
    default:
        wrongArgs()
    }
}

func gpuinfo(ctx *cli.Context) {
    eth.PrintOpenCLDevices()
}

func gpubench(ctx *cli.Context) {
    args := ctx.Args()
    wrongArgs := func() {
        utils.Fatalf(`Usage: geth gpubench <gpu number>`)
    }
    switch {
    case len(args) == 1:
        n, err := strconv.ParseUint(args[0], 0, 64)
        if err != nil {
            wrongArgs()
        }
        eth.GPUBench(n)
    case len(args) == 0:
        eth.GPUBench(0)
    default:
        wrongArgs()
    }
}

func version(c *cli.Context) {
    fmt.Println(ClientIdentifier)
    fmt.Println("Version:", Version)
    if gitCommit != "" {
        fmt.Println("Git Commit:", gitCommit)
    }
    fmt.Println("Protocol Versions:", eth.ProtocolVersions)
    fmt.Println("Network Id:", c.GlobalInt(utils.NetworkIdFlag.Name))
    fmt.Println("Go Version:", runtime.Version())
    fmt.Println("OS:", runtime.GOOS)
    fmt.Printf("GOPATH=%s\n", os.Getenv("GOPATH"))
    fmt.Printf("GOROOT=%s\n", runtime.GOROOT())
}