我正在将一个CLI库从Ruby移植到Node.js。在我的代码中，必要时我会执行几个第三方二进制文件。我不确定如何在Node中实现这一点。
下面是Ruby中的一个示例，我调用PrinceXML将文件转换为PDF：
cmd = system("prince -v builds/pdf/book.html -o builds/pdf/book.pdf")
Node中的等效代码是什么？
当前回答
对于更新版本的Node.js（v8.1.4），事件和调用与旧版本相似或相同，但鼓励使用标准的更新语言特性。示例：
对于缓冲的、非流格式的输出（一次获得所有输出），请使用child_process.exec：
const { exec } = require('child_process');
exec('cat *.js bad_file | wc -l', (err, stdout, stderr) => {
if (err) {
// node couldn't execute the command
return;
}
// the *entire* stdout and stderr (buffered)
console.log(`stdout: ${stdout}`);
console.log(`stderr: ${stderr}`);
});
您也可以将其与Promises一起使用：
const util = require('util');
const exec = util.promisify(require('child_process').exec);
async function ls() {
const { stdout, stderr } = await exec('ls');
console.log('stdout:', stdout);
console.log('stderr:', stderr);
}
ls();
如果希望逐步接收数据块（作为流输出），请使用child_process.spawn：
const { spawn } = require('child_process');
const child = spawn('ls', ['-lh', '/usr']);
// use child.stdout.setEncoding('utf8'); if you want text chunks
child.stdout.on('data', (chunk) => {
// data from standard output is here as buffers
});
// since these are streams, you can pipe them elsewhere
child.stderr.pipe(dest);
child.on('close', (code) => {
console.log(`child process exited with code ${code}`);
});
这两个函数都有一个同步对应函数。child_process.execSync的示例：
const { execSync } = require('child_process');
// stderr is sent to stderr of parent process
// you can set options.stdio if you want it to go elsewhere
let stdout = execSync('ls');
以及child_process.s当兵同步：
const { spawnSync} = require('child_process');
const child = spawnSync('ls', ['-lh', '/usr']);
console.log('error', child.error);
console.log('stdout ', child.stdout);
console.log('stderr ', child.stderr);
注意：以下代码仍然有效，但主要针对ES5及以前版本的用户。
使用Node.js生成子进程的模块在文档（v5.00）中有详细说明。要执行命令并获取其完整输出作为缓冲区，请使用child_process.exec：
var exec = require('child_process').exec;
var cmd = 'prince -v builds/pdf/book.html -o builds/pdf/book.pdf';
exec(cmd, function(error, stdout, stderr) {
// command output is in stdout
});
如果您需要对流使用handle process I/O，例如当您需要大量输出时，请使用child_process.spawn：
var spawn = require('child_process').spawn;
var child = spawn('prince', [
'-v', 'builds/pdf/book.html',
'-o', 'builds/pdf/book.pdf'
]);
child.stdout.on('data', function(chunk) {
// output will be here in chunks
});
// or if you want to send output elsewhere
child.stdout.pipe(dest);
如果您执行的是文件而不是命令，则可能需要使用child_process.execFile，这些参数与派生几乎相同，但有第四个回调参数（如exec）用于检索输出缓冲区。看起来可能有点像这样：
var execFile = require('child_process').execFile;
execFile(file, args, options, function(error, stdout, stderr) {
// command output is in stdout
});
从v0.11.12开始，Node现在支持同步派生和执行。上面描述的所有方法都是异步的，并且有一个同步的对应方法。可以在此处找到它们的文档。虽然它们对脚本编写很有用，但请注意，与用于异步派生子进程的方法不同，同步方法不会返回ChildProcess的实例。
其他回答
const exec = require("child_process").exec
exec("ls", (error, stdout, stderr) => {
//do whatever here
})
对于更新版本的Node.js（v8.1.4），事件和调用与旧版本相似或相同，但鼓励使用标准的更新语言特性。示例：
对于缓冲的、非流格式的输出（一次获得所有输出），请使用child_process.exec：
const { exec } = require('child_process');
exec('cat *.js bad_file | wc -l', (err, stdout, stderr) => {
if (err) {
// node couldn't execute the command
return;
}
// the *entire* stdout and stderr (buffered)
console.log(`stdout: ${stdout}`);
console.log(`stderr: ${stderr}`);
});
您也可以将其与Promises一起使用：
const util = require('util');
const exec = util.promisify(require('child_process').exec);
async function ls() {
const { stdout, stderr } = await exec('ls');
console.log('stdout:', stdout);
console.log('stderr:', stderr);
}
ls();
如果希望逐步接收数据块（作为流输出），请使用child_process.spawn：
const { spawn } = require('child_process');
const child = spawn('ls', ['-lh', '/usr']);
// use child.stdout.setEncoding('utf8'); if you want text chunks
child.stdout.on('data', (chunk) => {
// data from standard output is here as buffers
});
// since these are streams, you can pipe them elsewhere
child.stderr.pipe(dest);
child.on('close', (code) => {
console.log(`child process exited with code ${code}`);
});
这两个函数都有一个同步对应函数。child_process.execSync的示例：
const { execSync } = require('child_process');
// stderr is sent to stderr of parent process
// you can set options.stdio if you want it to go elsewhere
let stdout = execSync('ls');
以及child_process.s当兵同步：
const { spawnSync} = require('child_process');
const child = spawnSync('ls', ['-lh', '/usr']);
console.log('error', child.error);
console.log('stdout ', child.stdout);
console.log('stderr ', child.stderr);
注意：以下代码仍然有效，但主要针对ES5及以前版本的用户。
使用Node.js生成子进程的模块在文档（v5.00）中有详细说明。要执行命令并获取其完整输出作为缓冲区，请使用child_process.exec：
var exec = require('child_process').exec;
var cmd = 'prince -v builds/pdf/book.html -o builds/pdf/book.pdf';
exec(cmd, function(error, stdout, stderr) {
// command output is in stdout
});
如果您需要对流使用handle process I/O，例如当您需要大量输出时，请使用child_process.spawn：
var spawn = require('child_process').spawn;
var child = spawn('prince', [
'-v', 'builds/pdf/book.html',
'-o', 'builds/pdf/book.pdf'
]);
child.stdout.on('data', function(chunk) {
// output will be here in chunks
});
// or if you want to send output elsewhere
child.stdout.pipe(dest);
如果您执行的是文件而不是命令，则可能需要使用child_process.execFile，这些参数与派生几乎相同，但有第四个回调参数（如exec）用于检索输出缓冲区。看起来可能有点像这样：
var execFile = require('child_process').execFile;
execFile(file, args, options, function(error, stdout, stderr) {
// command output is in stdout
});
从v0.11.12开始，Node现在支持同步派生和执行。上面描述的所有方法都是异步的，并且有一个同步的对应方法。可以在此处找到它们的文档。虽然它们对脚本编写很有用，但请注意，与用于异步派生子进程的方法不同，同步方法不会返回ChildProcess的实例。
使用这个轻量级npm包：系统命令
看看这里。
按如下方式导入：
const system = require('system-commands')
运行以下命令：
system('ls').then(output => {
console.log(output)
}).catch(error => {
console.error(error)
})
现在，可以按如下方式使用shelljs（从节点v4）：
var shell = require('shelljs');
shell.echo('hello world');
shell.exec('node --version');
使用安装
npm install shelljs
看见https://github.com/shelljs/shelljs
我刚刚编写了一个Cli-helper来轻松处理Unix/windows。
Java脚本：
define(["require", "exports"], function (require, exports) {
/**
* Helper to use the Command Line Interface (CLI) easily with both Windows and Unix environments.
* Requires underscore or lodash as global through "_".
*/
var Cli = (function () {
function Cli() {}
/**
* Execute a CLI command.
* Manage Windows and Unix environment and try to execute the command on both env if fails.
* Order: Windows -> Unix.
*
* @param command Command to execute. ('grunt')
* @param args Args of the command. ('watch')
* @param callback Success.
* @param callbackErrorWindows Failure on Windows env.
* @param callbackErrorUnix Failure on Unix env.
*/
Cli.execute = function (command, args, callback, callbackErrorWindows, callbackErrorUnix) {
if (typeof args === "undefined") {
args = [];
}
Cli.windows(command, args, callback, function () {
callbackErrorWindows();
try {
Cli.unix(command, args, callback, callbackErrorUnix);
} catch (e) {
console.log('------------- Failed to perform the command: "' + command + '" on all environments. -------------');
}
});
};
/**
* Execute a command on Windows environment.
*
* @param command Command to execute. ('grunt')
* @param args Args of the command. ('watch')
* @param callback Success callback.
* @param callbackError Failure callback.
*/
Cli.windows = function (command, args, callback, callbackError) {
if (typeof args === "undefined") {
args = [];
}
try {
Cli._execute(process.env.comspec, _.union(['/c', command], args));
callback(command, args, 'Windows');
} catch (e) {
callbackError(command, args, 'Windows');
}
};
/**
* Execute a command on Unix environment.
*
* @param command Command to execute. ('grunt')
* @param args Args of the command. ('watch')
* @param callback Success callback.
* @param callbackError Failure callback.
*/
Cli.unix = function (command, args, callback, callbackError) {
if (typeof args === "undefined") {
args = [];
}
try {
Cli._execute(command, args);
callback(command, args, 'Unix');
} catch (e) {
callbackError(command, args, 'Unix');
}
};
/**
* Execute a command no matters what's the environment.
*
* @param command Command to execute. ('grunt')
* @param args Args of the command. ('watch')
* @private
*/
Cli._execute = function (command, args) {
var spawn = require('child_process').spawn;
var childProcess = spawn(command, args);
childProcess.stdout.on("data", function (data) {
console.log(data.toString());
});
childProcess.stderr.on("data", function (data) {
console.error(data.toString());
});
};
return Cli;
})();
exports.Cli = Cli;
});
打字原始源文件：
/**
* Helper to use the Command Line Interface (CLI) easily with both Windows and Unix environments.
* Requires underscore or lodash as global through "_".
*/
export class Cli {
/**
* Execute a CLI command.
* Manage Windows and Unix environment and try to execute the command on both env if fails.
* Order: Windows -> Unix.
*
* @param command Command to execute. ('grunt')
* @param args Args of the command. ('watch')
* @param callback Success.
* @param callbackErrorWindows Failure on Windows env.
* @param callbackErrorUnix Failure on Unix env.
*/
public static execute(command: string, args: string[] = [], callback ? : any, callbackErrorWindows ? : any, callbackErrorUnix ? : any) {
Cli.windows(command, args, callback, function () {
callbackErrorWindows();
try {
Cli.unix(command, args, callback, callbackErrorUnix);
} catch (e) {
console.log('------------- Failed to perform the command: "' + command + '" on all environments. -------------');
}
});
}
/**
* Execute a command on Windows environment.
*
* @param command Command to execute. ('grunt')
* @param args Args of the command. ('watch')
* @param callback Success callback.
* @param callbackError Failure callback.
*/
public static windows(command: string, args: string[] = [], callback ? : any, callbackError ? : any) {
try {
Cli._execute(process.env.comspec, _.union(['/c', command], args));
callback(command, args, 'Windows');
} catch (e) {
callbackError(command, args, 'Windows');
}
}
/**
* Execute a command on Unix environment.
*
* @param command Command to execute. ('grunt')
* @param args Args of the command. ('watch')
* @param callback Success callback.
* @param callbackError Failure callback.
*/
public static unix(command: string, args: string[] = [], callback ? : any, callbackError ? : any) {
try {
Cli._execute(command, args);
callback(command, args, 'Unix');
} catch (e) {
callbackError(command, args, 'Unix');
}
}
/**
* Execute a command no matters what's the environment.
*
* @param command Command to execute. ('grunt')
* @param args Args of the command. ('watch')
* @private
*/
private static _execute(command, args) {
var spawn = require('child_process').spawn;
var childProcess = spawn(command, args);
childProcess.stdout.on("data", function (data) {
console.log(data.toString());
});
childProcess.stderr.on("data", function (data) {
console.error(data.toString());
});
}
}
Example of use:
Cli.execute(Grunt._command, args, function (command, args, env) {
console.log('Grunt has been automatically executed. (' + env + ')');
}, function (command, args, env) {
console.error('------------- Windows "' + command + '" command failed, trying Unix... ---------------');
}, function (command, args, env) {
console.error('------------- Unix "' + command + '" command failed too. ---------------');
});
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