path: root/cmd/geth/consolecmd.go

// Copyright 2016 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 (
    "os"
    "os/signal"

    "github.com/ethereum/go-ethereum/cmd/utils"
    "github.com/ethereum/go-ethereum/console"
    "gopkg.in/urfave/cli.v1"
)

var (
    consoleCommand = cli.Command{
        Action: localConsole,
        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
`,
    }
    attachCommand = cli.Command{
        Action: remoteConsole,
        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.
    `,
    }
    javascriptCommand = cli.Command{
        Action: ephemeralConsole,
        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
`,
    }
)

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

    // Attach to the newly started node and start the JavaScript console
    client, err := node.Attach()
    if err != nil {
        utils.Fatalf("Failed to attach to the inproc geth: %v", err)
    }
    config := console.Config{
        DataDir: node.DataDir(),
        DocRoot: ctx.GlobalString(utils.JSpathFlag.Name),
        Client:  client,
        Preload: utils.MakeConsolePreloads(ctx),
    }
    console, err := console.New(config)
    if err != nil {
        utils.Fatalf("Failed to start the JavaScript console: %v", err)
    }
    defer console.Stop(false)

    // If only a short execution was requested, evaluate and return
    if script := ctx.GlobalString(utils.ExecFlag.Name); script != "" {
        console.Evaluate(script)
        return nil
    }
    // Otherwise print the welcome screen and enter interactive mode
    console.Welcome()
    console.Interactive()

    return nil
}

// remoteConsole will connect to a remote geth instance, attaching a JavaScript
// console to it.
func remoteConsole(ctx *cli.Context) error {
    // Attach to a remotely running geth instance and start the JavaScript console
    client, err := utils.NewRemoteRPCClient(ctx)
    if err != nil {
        utils.Fatalf("Unable to attach to remote geth: %v", err)
    }
    config := console.Config{
        DataDir: utils.MustMakeDataDir(ctx),
        DocRoot: ctx.GlobalString(utils.JSpathFlag.Name),
        Client:  client,
        Preload: utils.MakeConsolePreloads(ctx),
    }
    console, err := console.New(config)
    if err != nil {
        utils.Fatalf("Failed to start the JavaScript console: %v", err)
    }
    defer console.Stop(false)

    // If only a short execution was requested, evaluate and return
    if script := ctx.GlobalString(utils.ExecFlag.Name); script != "" {
        console.Evaluate(script)
        return nil
    }
    // Otherwise print the welcome screen and enter interactive mode
    console.Welcome()
    console.Interactive()

    return nil
}

// ephemeralConsole starts a new geth node, attaches an ephemeral JavaScript
// console to it, and each of the files specified as arguments and tears the
// everything down.
func ephemeralConsole(ctx *cli.Context) error {
    // Create and start the node based on the CLI flags
    node := utils.MakeSystemNode(clientIdentifier, verString, relConfig, makeDefaultExtra(), ctx)
    startNode(ctx, node)
    defer node.Stop()

    // Attach to the newly started node and start the JavaScript console
    client, err := node.Attach()
    if err != nil {
        utils.Fatalf("Failed to attach to the inproc geth: %v", err)
    }
    config := console.Config{
        DataDir: node.DataDir(),
        DocRoot: ctx.GlobalString(utils.JSpathFlag.Name),
        Client:  client,
        Preload: utils.MakeConsolePreloads(ctx),
    }
    console, err := console.New(config)
    if err != nil {
        utils.Fatalf("Failed to start the JavaScript console: %v", err)
    }
    defer console.Stop(false)

    // Evaluate each of the specified JavaScript files
    for _, file := range ctx.Args() {
        if err = console.Execute(file); err != nil {
            utils.Fatalf("Failed to execute %s: %v", file, err)
        }
    }
    // Wait for pending callbacks, but stop for Ctrl-C.
    abort := make(chan os.Signal, 1)
    signal.Notify(abort, os.Interrupt)

    go func() {
        <-abort
        os.Exit(0)
    }()
    console.Stop(true)

    return nil
}