// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package console
import (
"fmt"
"io"
"io/ioutil"
"os"
"os/signal"
"path/filepath"
"regexp"
"sort"
"strings"
"github.com/ethereum/go-ethereum/internal/jsre"
"github.com/ethereum/go-ethereum/internal/web3ext"
"github.com/ethereum/go-ethereum/rpc"
"github.com/mattn/go-colorable"
"github.com/peterh/liner"
"github.com/robertkrimen/otto"
)
var (
passwordRegexp = regexp.MustCompile("personal.[nus]")
onlyWhitespace = regexp.MustCompile("^\\s*$")
exit = regexp.MustCompile("^\\s*exit\\s*;*\\s*$")
)
// HistoryFile is the file within the data directory to store input scrollback.
const HistoryFile = "history"
// DefaultPrompt is the default prompt line prefix to use for user input querying.
const DefaultPrompt = "> "
// Config is te collection of configurations to fine tune the behavior of the
// JavaScript console.
type Config struct {
DataDir string // Data directory to store the console history at
DocRoot string // Filesystem path from where to load JavaScript files from
Client *rpc.Client // RPC client to execute Ethereum requests through
Prompt string // Input prompt prefix string (defaults to DefaultPrompt)
Prompter UserPrompter // Input prompter to allow interactive user feedback (defaults to TerminalPrompter)
Printer io.Writer // Output writer to serialize any display strings to (defaults to os.Stdout)
Preload []string // Absolute paths to JavaScript files to preload
}
// Console is a JavaScript interpreted runtime environment. It is a fully fleged
// JavaScript console attached to a running node via an external or in-process RPC
// client.
type Console struct {
client *rpc.Client // RPC client to execute Ethereum requests through
jsre *jsre.JSRE // JavaScript runtime environment running the interpreter
prompt string // Input prompt prefix string
prompter UserPrompter // Input prompter to allow interactive user feedback
histPath string // Absolute path to the console scrollback history
history []string // Scroll history maintained by the console
printer io.Writer // Output writer to serialize any display strings to
}
func New(config Config) (*Console, error) {
// Handle unset config values gracefully
if config.Prompter == nil {
config.Prompter = Stdin
}
if config.Prompt == "" {
config.Prompt = DefaultPrompt
}
if config.Printer == nil {
config.Printer = colorable.NewColorableStdout()
}
// Initialize the console and return
console := &Console{
client: config.Client,
jsre: jsre.New(config.DocRoot, config.Printer),
prompt: config.Prompt,
prompter: config.Prompter,
printer: config.Printer,
histPath: filepath.Join(config.DataDir, HistoryFile),
}
if err := console.init(config.Preload); err != nil {
return nil, err
}
return console, nil
}
// init retrieves the available APIs from the remote RPC provider and initializes
// the console's JavaScript namespaces based on the exposed modules.
func (c *Console) init(preload []string) error {
// Initialize the JavaScript <-> Go RPC bridge
bridge := newBridge(c.client, c.prompter, c.printer)
c.jsre.Set("jeth", struct{}{})
jethObj, _ := c.jsre.Get("jeth")
jethObj.Object().Set("send", bridge.Send)
jethObj.Object().Set("sendAsync", bridge.Send)
consoleObj, _ := c.jsre.Get("console")
consoleObj.Object().Set("log", c.consoleOutput)
consoleObj.Object().Set("error", c.consoleOutput)
// Load all the internal utility JavaScript libraries
if err := c.jsre.Compile("bignumber.js", jsre.BigNumber_JS); err != nil {
return fmt.Errorf("bignumber.js: %v", err)
}
if err := c.jsre.Compile("web3.js", jsre.Web3_JS); err != nil {
return fmt.Errorf("web3.js: %v", err)
}
if _, err := c.jsre.Run("var Web3 = require('web3');"); err != nil {
return fmt.Errorf("web3 require: %v", err)
}
if _, err := c.jsre.Run("var web3 = new Web3(jeth);"); err != nil {
return fmt.Errorf("web3 provider: %v", err)
}
// Load the supported APIs into the JavaScript runtime environment
apis, err := c.client.SupportedModules()
if err != nil {
return fmt.Errorf("api modules: %v", err)
}
flatten := "var eth = web3.eth; var personal = web3.personal; "
for api := range apis {
if api == "web3" {
continue // manually mapped or ignore
}
if file, ok := web3ext.Modules[api]; ok {
if err = c.jsre.Compile(fmt.Sprintf("%s.js", api), file); err != nil {
return fmt.Errorf("%s.js: %v", api, err)
}
flatten += fmt.Sprintf("var %s = web3.%s; ", api, api)
}
}
if _, err = c.jsre.Run(flatten); err != nil {
return fmt.Errorf("namespace flattening: %v", err)
}
// Initialize the global name register (disabled for now)
//c.jsre.Run(`var GlobalRegistrar = eth.contract(` + registrar.GlobalRegistrarAbi + `); registrar = GlobalRegistrar.at("` + registrar.GlobalRegistrarAddr + `");`)
// If the console is in interactive mode, instrument password related methods to query the user
if c.prompter != nil {
// Retrieve the account management object to instrument
personal, err := c.jsre.Get("personal")
if err != nil {
return err
}
// Override the unlockAccount, newAccount and sign methods since these require user interaction.
// Assign these method in the Console the original web3 callbacks. These will be called by the jeth.*
// methods after they got the password from the user and send the original web3 request to the backend.
if obj := personal.Object(); obj != nil { // make sure the personal api is enabled over the interface
if _, err = c.jsre.Run(`jeth.unlockAccount = personal.unlockAccount;`); err != nil {
return fmt.Errorf("personal.unlockAccount: %v", err)
}
if _, err = c.jsre.Run(`jeth.newAccount = personal.newAccount;`); err != nil {
return fmt.Errorf("personal.newAccount: %v", err)
}
if _, err = c.jsre.Run(`jeth.sign = personal.sign;`); err != nil {
return fmt.Errorf("personal.sign: %v", err)
}
obj.Set("unlockAccount", bridge.UnlockAccount)
obj.Set("newAccount", bridge.NewAccount)
obj.Set("sign", bridge.Sign)
}
}
// The admin.sleep and admin.sleepBlocks are offered by the console and not by the RPC layer.
admin, err := c.jsre.Get("admin")
if err != nil {
return err
}
if obj := admin.Object(); obj != nil { // make sure the admin api is enabled over the interface
obj.Set("sleepBlocks", bridge.SleepBlocks)
obj.Set("sleep", bridge.Sleep)
}
// Preload any JavaScript files before starting the console
for _, path := range preload {
if err := c.jsre.Exec(path); err != nil {
failure := err.Error()
if ottoErr, ok := err.(*otto.Error); ok {
failure = ottoErr.String()
}
return fmt.Errorf("%s: %v", path, failure)
}
}
// Configure the console's input prompter for scrollback and tab completion
if c.prompter != nil {
if content, err := ioutil.ReadFile(c.histPath); err != nil {
c.prompter.SetHistory(nil)
} else {
c.history = strings.Split(string(content), "\n")
c.prompter.SetHistory(c.history)
}
c.prompter.SetWordCompleter(c.AutoCompleteInput)
}
return nil
}
// consoleOutput is an override for the console.log and console.error methods to
// stream the output into the configured output stream instead of stdout.
func (c *Console) consoleOutput(call otto.FunctionCall) otto.Value {
output := []string{}
for _, argument := range call.ArgumentList {
output = append(output, fmt.Sprintf("%v", argument))
}
fmt.Fprintln(c.printer, strings.Join(output, " "))
return otto.Value{}
}
// AutoCompleteInput is a pre-assembled word completer to be used by the user
// input prompter to provide hints to the user about the methods available.
func (c *Console) AutoCompleteInput(line string, pos int) (string, []string, string) {
// No completions can be provided for empty inputs
if len(line) == 0 || pos == 0 {
return "", nil, ""
}
// Chunck data to relevant part for autocompletion
// E.g. in case of nested lines eth.getBalance(eth.coinb<tab><tab>
start := 0
for start = pos - 1; start > 0; start-- {
// Skip all methods and namespaces (i.e. including te dot)
if line[start] == '.' || (line[start] >= 'a' && line[start] <= 'z') || (line[start] >= 'A' && line[start] <= 'Z') {
continue
}
// Handle web3 in a special way (i.e. other numbers aren't auto completed)
if start >= 3 && line[start-3:start] == "web3" {
start -= 3
continue
}
// We've hit an unexpected character, autocomplete form here
start++
break
}
return line[:start], c.jsre.CompleteKeywords(line[start:pos]), line[pos:]
}
// Welcome show summary of current Geth instance and some metadata about the
// console's available modules.
func (c *Console) Welcome() {
// Print some generic Geth metadata
fmt.Fprintf(c.printer, "Welcome to the Geth JavaScript console!\n\n")
c.jsre.Run(`
console.log("instance: " + web3.version.node);
console.log("coinbase: " + eth.coinbase);
console.log("at block: " + eth.blockNumber + " (" + new Date(1000 * eth.getBlock(eth.blockNumber).timestamp) + ")");
console.log(" datadir: " + admin.datadir);
`)
// List all the supported modules for the user to call
if apis, err := c.client.SupportedModules(); err == nil {
modules := make([]string, 0, len(apis))
for api, version := range apis {
modules = append(modules, fmt.Sprintf("%s:%s", api, version))
}
sort.Strings(modules)
fmt.Fprintln(c.printer, " modules:", strings.Join(modules, " "))
}
fmt.Fprintln(c.printer)
}
// Evaluate executes code and pretty prints the result to the specified output
// stream.
func (c *Console) Evaluate(statement string) error {
defer func() {
if r := recover(); r != nil {
fmt.Fprintf(c.printer, "[native] error: %v\n", r)
}
}()
if err := c.jsre.Evaluate(statement, c.printer); err != nil {
return err
}
return nil
}
// Interactive starts an interactive user session, where input is propted from
// the configured user prompter.
func (c *Console) Interactive() {
var (
prompt = c.prompt // Current prompt line (used for multi-line inputs)
indents = 0 // Current number of input indents (used for multi-line inputs)
input = "" // Current user input
scheduler = make(chan string) // Channel to send the next prompt on and receive the input
)
// Start a goroutine to listen for promt requests and send back inputs
go func() {
for {
// Read the next user input
line, err := c.prompter.PromptInput(<-scheduler)
if err != nil {
// In case of an error, either clear the prompt or fail
if err == liner.ErrPromptAborted { // ctrl-C
prompt, indents, input = c.prompt, 0, ""
scheduler <- ""
continue
}
close(scheduler)
return
}
// User input retrieved, send for interpretation and loop
scheduler <- line
}
}()
// Monitor Ctrl-C too in case the input is empty and we need to bail
abort := make(chan os.Signal, 1)
signal.Notify(abort, os.Interrupt)
// Start sending prompts to the user and reading back inputs
for {
// Send the next prompt, triggering an input read and process the result
scheduler <- prompt
select {
case <-abort:
// User forcefully quite the console
fmt.Fprintln(c.printer, "caught interrupt, exiting")
return
case line, ok := <-scheduler:
// User input was returned by the prompter, handle special cases
if !ok || (indents <= 0 && exit.MatchString(line)) {
return
}
if onlyWhitespace.MatchString(line) {
continue
}
// Append the line to the input and check for multi-line interpretation
input += line + "\n"
indents = countIndents(input)
if indents <= 0 {
prompt = c.prompt
} else {
prompt = strings.Repeat(".", indents*3) + " "
}
// If all the needed lines are present, save the command and run
if indents <= 0 {
if len(input) > 0 && input[0] != ' ' && !passwordRegexp.MatchString(input) {
if command := strings.TrimSpace(input); len(c.history) == 0 || command != c.history[len(c.history)-1] {
c.history = append(c.history, command)
if c.prompter != nil {
c.prompter.AppendHistory(command)
}
}
}
c.Evaluate(input)
input = ""
}
}
}
}
// countIndents returns the number of identations for the given input.
// In case of invalid input such as var a = } the result can be negative.
func countIndents(input string) int {
var (
indents = 0
inString = false
strOpenChar = ' ' // keep track of the string open char to allow var str = "I'm ....";
charEscaped = false // keep track if the previous char was the '\' char, allow var str = "abc\"def";
)
for _, c := range input {
switch c {
case '\\':
// indicate next char as escaped when in string and previous char isn't escaping this backslash
if !charEscaped && inString {
charEscaped = true
}
case '\'', '"':
if inString && !charEscaped && strOpenChar == c { // end string
inString = false
} else if !inString && !charEscaped { // begin string
inString = true
strOpenChar = c
}
charEscaped = false
case '{', '(':
if !inString { // ignore brackets when in string, allow var str = "a{"; without indenting
indents++
}
charEscaped = false
case '}', ')':
if !inString {
indents--
}
charEscaped = false
default:
charEscaped = false
}
}
return indents
}
// Execute runs the JavaScript file specified as the argument.
func (c *Console) Execute(path string) error {
return c.jsre.Exec(path)
}
// Stop cleans up the console and terminates the runtime envorinment.
func (c *Console) Stop(graceful bool) error {
if err := ioutil.WriteFile(c.histPath, []byte(strings.Join(c.history, "\n")), 0600); err != nil {
return err
}
if err := os.Chmod(c.histPath, 0600); err != nil { // Force 0600, even if it was different previously
return err
}
c.jsre.Stop(graceful)
return nil
}
