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?
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
@六氰的答案几乎是完整的。在Windows命令prince可以是prince.exe、prince.cmd、prince.bat或prince(我不知道gems是如何绑定的,但npm bin附带了sh脚本和批处理脚本-npm和npm.cmd)。如果你想编写一个在Unix和Windows上运行的可移植脚本,你必须生成正确的可执行文件。
这里有一个简单但可移植的派生函数:
function spawn(cmd, args, opt) {
var isWindows = /win/.test(process.platform);
if ( isWindows ) {
if ( !args ) args = [];
args.unshift(cmd);
args.unshift('/c');
cmd = process.env.comspec;
}
return child_process.spawn(cmd, args, opt);
}
var cmd = spawn("prince", ["-v", "builds/pdf/book.html", "-o", "builds/pdf/book.pdf"])
// Use these props to get execution results:
// cmd.stdin;
// cmd.stdout;
// cmd.stderr;
其他回答
您正在查找child_process.exec
以下是示例:
const exec = require('child_process').exec;
const child = exec('cat *.js bad_file | wc -l',
(error, stdout, stderr) => {
console.log(`stdout: ${stdout}`);
console.log(`stderr: ${stderr}`);
if (error !== null) {
console.log(`exec error: ${error}`);
}
});
由于版本4,最接近的替代方法是child_process.execSync方法:
const {execSync} = require('child_process');
let output = execSync('prince -v builds/pdf/book.html -o builds/pdf/book.pdf');
⚠️ 请注意,execSync调用会阻塞事件循环。
如果您不介意依赖关系,并且希望使用promise,那么子进程promise可以:
安装
npm install child-process-promise --save
exec用法
var exec = require('child-process-promise').exec;
exec('echo hello')
.then(function (result) {
var stdout = result.stdout;
var stderr = result.stderr;
console.log('stdout: ', stdout);
console.log('stderr: ', stderr);
})
.catch(function (err) {
console.error('ERROR: ', err);
});
派生用法
var spawn = require('child-process-promise').spawn;
var promise = spawn('echo', ['hello']);
var childProcess = promise.childProcess;
console.log('[spawn] childProcess.pid: ', childProcess.pid);
childProcess.stdout.on('data', function (data) {
console.log('[spawn] stdout: ', data.toString());
});
childProcess.stderr.on('data', function (data) {
console.log('[spawn] stderr: ', data.toString());
});
promise.then(function () {
console.log('[spawn] done!');
})
.catch(function (err) {
console.error('[spawn] ERROR: ', err);
});
ECMAScript模块导入。。。from语法
import {exec} from 'child-process-promise';
let result = await exec('echo hi');
console.log(result.stdout);
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. ---------------');
});