Nodejs spawn vs exec vs fork. Each of the methods returns a ChildProcess instance.
Nodejs spawn vs exec vs fork js runs in a single thread. Nodejs documentation states: For example, if the server has installed software, commands, bash scripts, etc. spawn()`][], [`child_process. Just making it clear, that ultimately spawn encompasses fork. Dec 13, 2023 · In Node. js functions require ('child_process'). We’ll first explore spawn() and then spawnSync Executing files or commands with Child Processes Spawning a new process to execute a command To spawn a new process in which you need unbuffered output (e. js event loop. js spawn, exec, fork, and execFile to run external commands, spawn processes, and handle parallel execution. js 子进程而生 fork 函数是 child_process 模块中专门用于创建 Node. Difference Between exec () And spawn () In Node. execFile(): Similar to exec() but directly executes a file. On the other hand, exec buffers output in a small (by default 1MB, 200 KB till v11. js. This method spawns a new process using a given command and an array of arguments. stout Jun 7, 2022 · TL;DR: the solution. exec () Child_process. js Child Processes module (child_process) has two functions spawn and exec, using which we can start a child process to execute other programs on the system. Asynchronous Process Creation # The child_process. Sep 9, 2024 · To create a child process, Node. js This thread might be outdated since I was using Node. This article will explore the differences between spawn() and fork() in Node. Whether you're running a shell script, invoking a system command, or working with another executable, Node. , and you want to call them from Node. js, interacting with external processes is a common requirement. fork() since, if a command can be run from the command line, there should be no reason it cannot be run asychronously from Node. We need to invoke some Matlab-implemented algorithm using OpenCV on Visual C++. exec 4. It is the application's responsibility to manage the worker pool based on its own needs. Jun 3, 2016 · In Node, the child_process module provides four different methods for executing external applications: 1. fork (): spawns a new Node. spawn() used specifically to spawn new Node. Aug 5, 2016 · I understand that node js fork function creates a new V8 instance, in contrast to the spawn function which does not. In short, use spawn for interactive commands and exec for non-interactive commands. The fork() method is a special case of spawn() specifically for creating Node. But this would be silly, because fork does some things to optimize the process of creating V8 instances. Each method is explained with detailed points, practical examples, and a summary at the end. exec和execFile可以在回调中拿到返回的buffer的内容（执行成功或失败的输出） 3. e resources utilised or altered by the parent process will be accessed by the child. That's because spawn streams input/output with a child process. Each of the methods returns a ChildProcess instance. Oct 8, 2024 · 在 Node. Nov 28, 2020 · The child_process. Note that OP has used the array argument for spawn, which is appropriate for shell: false. Fork creates a child process that is a copy of the parent process, while spawn creates a new process from scratch. js gives developers powerful tools to manage external processes and scale applications efficiently. Asynchronous process creation # The child_process. stdin - WriteStream, . exec() that will block the Node. Exec is typically used for short-lived processes, while fork and spawn are typically used for long-lived processes. Mar 10, 2025 · 需要执行各种类型的可执行文件。 性能： 由于 spawn 直接与底层系统调用交互，并且支持流式数据传输，因此它的性能通常是最高的。 2. js provides several ways to create child processes, enabling you to run tasks in parallel and leverage multi-core systems efficiently. It establishes an IPC (Inter-Process Communication) channel between the parent and child processes, allowing them to communicate via message passing. Two of the most frequently used methods for this purpose are `exec` and `spawn` from the `child_process` module. Child Processes Child Processes enable you to spawn separate processes to run tasks independently from the main Node. fork () Special case of spawn () used to run a new Node. execFile()`][] methods all follow the idiomatic asynchronous In this chapter, we’ll explore how we can execute shell commands from Node. However, due to buffering, it has a memory May 17, 2020 · By default, child_process. The main difference between fork_mode and cluster_mode is that it orders pm2 to use either the child_process. The return Feb 12, 2025 · In Node. Nov 23, 2024 · Learn the key differences between Node. spawn can also directly use IO streams of the parent/caller by specifying stdio: inherit option. child_process. js applications. today I go over the low level details on the difference between fork and spawn as well as how that's relevant for flake8! playlist: • anthony explains ========== twitch: / anthonywritescode Jul 31, 2020 · The main benefit of using fork() to create a Node. js の Child Process 研究 : fork・exec・execFile・spawn の違いをサンプルコードとともに検証 Node. This module enables us to execute system commands, either by spawning a new terminal/shell process or by launching Node scripts. js process. js在 child_process 模块中提供了 spawn 和 exec 这两个方法，用来开启子进程执行指定程序。 这两个方法虽然目的一样，但是既然Node. Oct 25, 2023 · There are several ways to create a child process in Node. spawn() or . js的单线程和非阻塞特性表现地非常好。然而，对于处理功能越来越复杂的应用程序而言，一个单进程的CPU是远远无法满足需要的。 无论你的服务器有多强大，单线程都是远远不够用的。 事实上，Node. js EventEmitter API, allowing the parent process to register listener functions that are called when certain Why are child processes useful? Could anyone provide use cases for when it would be correct to use one of the child process methods in node like fork, spawn, exec & execFile ? I'm largely self taught. You can, however take advantage of multiple processes. Supports IPC (Inter-Process Communication) for sending messages between parent and child. Currently I am making an application that does roll call in a classroom for teachers who don't want to waste their time on a roll call. It creates a separate V8 instance, allowing JavaScript files to run in separate processes, and facilitating direct communication between the parent and child. js 中， exec 、 execFile 、 spawn 和 fork 都是用于执行外部命令或脚本的方法，但它们在功能和使用场景上有所不同。以下是这些方法的区别和用途： exec (command [, options], callback) exec 方法用于执行一个shell命令，并将命令的输出作为回调函数参数返回。 这个方法会缓冲命令的输出，等待命令执行 Aug 26, 2020 · Node. fork(): Spawns a new Node. ) To Node. execSync (): a synchronous version of child_process. js为我们提供了两个方法，那它们之间必然还是会有一些不同之处，下面让我们来分析一下他们的异同。 Node. js process and establishes communication between parent and child. js can resolve against your system path. js application is a common task that allows you to execute system commands, scripts, or other applications. exec buffered output in a small (by default 200K) buffer. 10. Like spawn, a ChildProcess object is returned. spawn(). js, you can create child processes using various methods provided by the `child_process` module, among which `fork` and `spawn` are widely used. Use the exec () method to run shell-like syntax commands on a small data volume. spawn (), child_process. Jan 2, 2025 · 在Node. js。 非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。 Jan 9, 2017 · A simpler way of answering the question is rephrasing it to ask when you should use exec vs spawn. Sep 28, 2020 · spawn starts a Python child process from scratch without the parent process's memory, file descriptors, threads, etc. execFile() methods all follow the idiomatic asynchronous programming pattern typical of other Node. js child process module methods. Apr 9, 2018 · Node. js process, with the ability to communicate via IPC (Inter-Process Jun 7, 2021 · Performance between Worker thread vs child process fork in Node. . js中的单线程无阻塞性能非常适合单个进程。但是最终，一个CPU中的一个进程不足以处理应用程序不断增加的工作量。 无论您的服务器多么强大，一个线程只能支持有限的负载。 Node. By understanding the method's parameters, output handling, and potential errors, you can effectively use 'spawn' in your Node. js fournit la fonction fork(), une variation du spawn(), pour créer un processus enfant qui est également un processus Node. Some features to highlight of these methods in Nodejs: Oct 18, 2025 · In Node. Creating a Child Process Using fork() for Inter-Process Communication Nov 29, 2024 · 在 Node. js programs to perform complex tasks and processes. js script. Sep 2, 2024 · Node. Jun 19, 2024 · The spawn and fork methods in Node. You can specify a directory to use for the command being executed by spawn using cwd option. It is handy for running shell commands and recording the output. Mar 29, 2025 · spawn(): Starts a new process without blocking the event loop. Linux (Unix)에서 기본 값. Jun 6, 2022 · 3. Jul 25, 2013 · Ultimately you could use spawn in a way that did the above, by sending spawn a Node command. fork(): spawns a new Node. js, via module 'node:child_process'. fork() will spawn new Node. 들어가기 전에 이 글을 이해하기 위해서는 시스템 콜과 시스템 콜의 종류인 fork ()와 exec ()이 무엇인지 알아야한다. js' child_process module are used for creating child processes, but they serve different purposes and have different use cases. Although a primary use case for the node:cluster module is networking, it can also be used for other use cases requiring worker processes. js child_process module with spawn, exec, fork, and execFile. The returned process object will hold a property for each std type represented as a Stream: . js provides several built-in modules for this purpose, including child_process, which allows you to spawn, fork, and execute processes. The returned ChildProcess will have an additional communication channel built-in that allows messages to be passed back and forth between the parent and child. The first argument of the function represents a path for an executable file that should start the process, and the second argument is an arguments vector that will be given to the executable. js's child_process module used to create child processes, but they serve different purposes: 🔹 spawn () Aug 25, 2021 · 内容列表 Child process API spawn exec spawn vs exec 工具库 execa 参考资源 利用 Node. js 开发中，经常需要与其他命令行工具交互。Node. Node. js but it means data you send to the child process may not be immediately consumed. 1. 1 Overview of this chapter # Module 'node:child_process' has a function for executing shell commands (in spawned child processes) that comes in two versions: An asynchronous version spawn(). The fork() method is similar to spawn(), but it is specifically designed to spawn new Node. Technically, spawn forks a duplicate of the current process, then the child immediately calls exec to replace itself with a fresh Python, then asks Python to load the target module and run the target callable. Le principal avantage d’utiliser fork() pour créer un processus Node. They are suitable for tasks requiring isolation or Child Process Stability: 3 - Stable Node provides a tri-directional popen(3) facility through the child_process module. spawn 프로세스 생성 속도는 fork 보다 살짝 느리다. js does not automatically manage the number of workers, however. Jan 1, 2022 · fork vs spawn (fork_exec, clone 등) fork 현재 프로세스를 clone해 자식 프로세스를 생성함. fork El método fork del módulo child_process en Node. See subprocess. fork()`][], [`child_process. What does this means internally? Fork mode Take the fork mode as a basic process spawning. js中，exec、execFile、spawn和fork都是用于执行外部命令或脚本的方法，但它们之间有一些关键的区别和用途。以下是每个方法的简要概述和用途： exec (command [, options], callback) 概述：exec方法用于执行一个shell命令，并缓存命令的输 Feb 2, 2020 · Node. Sep 27, 2022 · The child_process module contains the following main methods that will help us create, manipulate, and run processes: exec, spawn, and fork. I understand how to create a REST API, write some auth logic and create web pages based off of templating with handlebars. js gives you powerful primitives for orchestrating processes and scaling workloads. fork：专为 Node. The [`child_process. js 子进程的方式。 Jun 14, 2021 · The NodeJS fork() method is a built-in function of the child_process module that allows you to create a child process that’s connected to the main process currently running your code. child_process module allows to create child processes in Node. exec (), and child_process. spawn(), child_process. js features a child_process module that allows developers to spawn and communicate with child processes. js process and invokes a specified module with an IPC communication channel established that allows sending messages between parent and child. js的单 相关用法 注： 本文 由纯净天空筛选整理自 namancourses 大神的英文原创作品 Difference between spawn () and fork () methods in Node. fork (), child_process. It simply creates a process to execute the command in spawn and returns the result, making it fast and efficient. Learn how to use Node. spawn 3. js中四种子进程创建方法：exec用于执行shell命令，execFile用于执行可执行文件，fork用于并行执行JavaScript文件并通过消息通信，spawn则支持复杂命令的流式处理。作者给出了适用场景和示例，帮助开发者选择合适的方法以提高代码效率和可读性。 The child_process. fork All of these are asynchronous. Unix Functionality we often use in the examples Spawning processes asynchronously: spawn() How spawn() works When is the shell command executed? Command-only mode vs. js, there is a 'close' and an 'exit' event on child processes. execFile () executes a file directly without using a shell. execFile () in that the latter won't spawn a shell whereas the former will. May 30, 2016 · When spawning child processes via spawn()/exec()/ in Node. Jan 7, 2024 · Child Processes: Multitasking in NodeJS Deep Dive in Child Processes, Spawn, Exec, ExecFile, Fork, IPC This article is the fifth article of my Advanced NodeJS for Senior Engineers Series. spawn 返回一个stream。 child_process. exec 返回一个buffer，而 child_process. This blog post aims to provide a comprehensive Mar 5, 2024 · The synchronous counterparts for the exec and execFile methods are execSync() and execFileSync() respectively fork () The fork () method is used for spawning new Node. js基于事件驱动来处理并发，它本身是以单线程模式运行的。Node. exec(), and child_process. If you need a command to happen after another, you can use spawnSync and other *Sync functions in the child_process module. We’re going to see the differences between these four functions and when to use each. Nov 30, 2023 · What is the Child Process Spawn Function? The spawn function belongs to Node. send() for details. May 27, 2025 · Alternatives child_process. Fork is just optimal for this particular, and very useful, use case. Sep 10, 2024 · Here's a quick rundown of the main methods provided by the child_process module: exec: Executes a command in a shell and buffers the output. exec () and child_process. js se utiliza para generar un nuevo proceso con una comunicación bidireccional entre el proceso padre y el proceso hijo. js environment. The child_process module provides flexibility for: System-level automation Language interoperability Horizontal service expansion Understanding the differences between spawn, exec, and fork allows you to use the right tool for each job — whether you're calling a Python model, automating Aug 19, 2025 · This article explains in simple words the differences between spawn, exec, and fork in Node. js 是單執行緒 (single-threaded) 的模型架構，可提升 CPU 使用率，但無論你的伺服器多麼強大，一個執行緒的負載量總是有限的。而子程序 (child Oct 23, 2014 · Node. execFile 2. js provides us with four primary methods for creating a child process which are the exec(), execFile(), spawn(), fork() The exec() method The exec () method runs a command in a shell and buffers the output. long-running processes which might print output over a period of time rather than printing and exiting immediately), use child_process. This allows to change the exec_interpreter, so that you can run a php or a python server with pm2. js is using one thread to run the user code and having a thread pool (in libuv) to handle the IO, network and database API calls. Those processes can easily communicate with each other using a built-in messaging system. g. Sep 27, 2018 · Docs: spawn The spawn function will spawn a new process of git log type. Overview of this blog post Windows vs. js 提供了两种不同的方式来实现这一目的：exec 和 spawn。本文将讨论这两种方式的区别和使用技巧，同时提供代码示例以帮助你更好地使用它们。 Feb 17, 2025 · fork() : Utilisé pour exécuter un script Node. Jun 17, 2015 · 前言 众所周知，Node. To cut a long story short, use spawn in case you need a lot of data Jun 8, 2017 · There are four different ways to create a child process in Node: spawn(), fork(), exec(), and execFile(). js spawn and exec, and when to use each approach for child processes effectively. Aug 21, 2025 · The fork () method is a special case of spawn () used specifically for spawning new NodeJS processes. This way the output from the script will be displayed immediately. The execPath property in the options object allows for an alternative execution Jul 22, 2025 · Published Jul 22, 2025 💡 Answer: Both spawn () and fork () are methods from Node. It sets up an IPC channel that allows sending messages between the parent and child processes. js using spawn and exec to run terminal commands directly from JavaScript! 🧠 more Jul 5, 2022 · In this blog post, we’ll explore how we can execute shell commands from Node. js, child processes are used to execute compute-requiring activities or activities that need to be executed concurrently with the main application. spawn () and require ('child_process'). js通过 child_process开启子进程执行指定程序。主要包括4个异步进程函数(spawn,exec,execFile,fork)和3个同步进程函数(spawnSync,execFileSync,… Dec 19, 2024 · The fork() method returns a special ChildProcess instance specifically for spawning additional Node. js (using methods like spawn(), fork(), exec(), and execFile()) and as always, reading the docs is advisable to get the full picture, but the simplest case of creating child processes is as simple as the script shown below: Jul 30, 2025 · 3. first, I believe you need to use execFile instead of spawn; execFile is for when you have the path to a script, whereas spawn is for executing a well-known command that Node. Provide a callback to process the buffered output Oct 31, 2023 · 如何使用spawn()，exec()，execFile()和fork() 对于单进程而言，Node. fork api or the cluster api. While they might seem similar, they serve different purposes and have distinct features. spawn launches a command in a new process: The Node. exec first spawns a subshell, and then tries to execute your process. js 0. Dec 19, 2024 · Worker Threads allow you to run JavaScript code in multiple threads. exec vs spawn There are two main approaches to running child processesL exec and spawn. 부모 프로세스의 모든 리소스를 카피한다. Oct 19, 2023 · Exec — use it when we need to execute a short-lived shell command Spawn — use it for long-lived processes and stream output and error streams back to the parent process Jun 29, 2025 · In this video, we explore the child_process module in Node. A synchronous version spawnSync(). js's child process module, serving as a powerful tool to execute external commands in separate processes. exec () executes a command within a shell. It also establishes an IPC channel for process communication. Nov 25, 2015 · For a long time, I had this big question in my mind: Should I use spawn or execFile? I am actually referring to the 2 Node. spawn() : Utilisé pour exécuter un processus et communiquer via stdin, stdout, et stderr. fork () Child_process. They are ideal for sharing memory between threads via SharedArrayBuffer and for offloading CPU-bound tasks like data processing or computations. fork(), child_process. exec () that will block the Node. js在单个线程中运行的事实并不… In this video you will learn how to create a #child-process in #nodejs, we would be looking into the 4 ways to create a child-process - #exec #execFile #spaw Nov 8, 2022 · Processes are created through different system calls, most popular are fork () and exec () fork () pid_t pid = fork(); fork () creates a new process by duplicating the calling process, The new process, referred to as child, is an exact duplicate of the calling process, referred to as parent, except for the following : Jan 2, 2024 · 本文详细介绍了Node. fork: Creates a new Node. exec()`][], and [`child_process. Calling these methods Apr 3, 2023 · Exec requires a shell environment, while fork and spawn can use a Node. Otherwise, use the spawn () command, as shown in this tutorial. exec是创建子shell去执行命令，用来直接执行shell命令 。 Todays video will demonstrate how we can offload some CPU intensive operations by creating a seperate process using the built in child_process library inside nodejs. Jul 4, 2025 · Conclusion Node. js par rapport à spawn() ou exec() est que fork() permet la communication entre le processus parent et le processus enfant. The spawn() method is generally used for running long-running processes, such as command-line utilities, and it is well-suited for streaming large amounts of data between the parent and child processes. Would it be correct to say that fork allows you to use multi-threading in node js (on a multi-core machine), and therefore fork is the best choice when you want to execute heavy-load scripts without affecting the performance of There is a difference between using child_process. This architecture is ok if you have lots of tasks that require a short process. args mode Sending data to the stdin of the child process Piping manually Aug 11, 2015 · I'm curious why you cannot use . Two commonly used methods for this purpose are spawn() and fork(). Understanding the differences and appropriate uses of these two methods is crucial for optimizing your Node. js provides multiple ways to execute external processes. exec(): Runs a shell command and buffers the output. spawn和fork都是返回一个基于流的子进程对象 2. spawn: Launches a new process with a given command, allowing you to stream data to and from the process. js 编写一些命令行工具、一次性脚本是很方便的，而在这类场景下 child_process API 的 spawn 和 exec 方法的应用则非常常见。在我使用它们时，却不知道该如何进行选择，遂对此进行了探究。 Child process API 先来看看 child_process API Exec requires a shell environment, while fork and spawn can use a Node. Jun 12, 2024 · Node. js instances using the process. Feb 24, 2018 · The documentation (both for exec and for spawn with shell: true), warns that this is vulnerable to injection attacks if the input is not sanitised. js的Child Processes模块 (child_process)中，有两个类似的方法exec和spawn，都是通过生成子进程去执行指定的命令。两个方法除了使用方法稍有不同外，最大的区别就是二者的返回值不一样。 child_process. Yes, the exec_interpreter is the "command" used to start the child child_process. Useful for creating worker processes. js の組み込みモジュール、 child_process。基本的には、実行中の node プロセスとは別のプロセスを生成する関数が揃っているモジュールだが、今回はこのモジュールの中の似たような関数を比較し、理解を Jan 15, 2013 · 120 I'm still getting my feet wet with Node. Typically, spawn is more suitable for long-running process with large outputs. May 11, 2023 · The two common ways to create a child process in Node. fork() method is a special case of spawn used specifically to spawn new Node. What is the difference between those two and when do you need to use what? Dec 6, 2023 · The following lists major OS Platforms and default start methods Windows : spawn macOS : spawn Linux : Fork As of now we focus on fork and spawn method Fork This fork method works on creating the exact clone or copy of the parent process. You can also pass shell variables to the child process using env option. Jan 7, 2020 · exec 和 spawn 各自拥有其同步版本的方法 execSync 和 spawnSync。 我们知道，同步代码意味着阻塞，意味着在同步调用之后的代码，应该能确定前面的代码意图是执行完成。 In this video you will learn the power of #child -process in #nodejs, we are going to demonstrate the #fork method of child-process by a practical example. It is possible to stream data through a child's stdin, stdout, and stderr in a fully non-blocking way. execSync(): a synchronous version of child_process. node:child_process 模块提供了以与 popen (3) 类似但不相同的方式生成子进程的能力。此功能主要由 child_process. This guide covers key differences, examples, and best practices. js process over spawn() or exec() is that fork() enables communication between the parent and the child process. js, the 'spawn' method provides a powerful way to create and manage child processes. That doesn't affect node. fork() method is a special case of child_process. send(). The child process won’t have access to environment variables of Jun 24, 2024 · Running external processes from within a Node. spawn () 函数提供： ️ With these three methods— exec(), spawn(), and fork() —Node. However, the command's output will not be printed to the terminal as it runs: you might decide to read the return value and send the command's output to your program's output yourself, but all output will be bunched up and printed at once. js et communiquer via process. js, use spawn. i. js APIs. The returned ChildProcess supports an additional IPC channel to allows messages communication between the parent and child. 26. js, but I have a few ideas. Oct 18, 2019 · Node. Feb 9, 2018 · The main difference is that spawn is more suitable for long-running processes with huge output. 12. execFile () executes a file directly The child_process. (Note that some programs use line-buffered I/O internally. In Node. x) buffer. execFile () are alternative methods for executing commands. execPath of the parent process. These objects implement the Node. There are four different ways to create a child process in Node: spawn(), fork(), exec(), and execFile(). js processes. Learn how to execute system commands using Node. execFile (). js Published on: Jun 7, 2021 Updated on: Aug 21, 2025 Overview Node. But, if you are running a task that involves heavy Mar 5, 2023 · Child_process. js are: Spawn: Run in background Exec: Run to completion Jun 29, 2019 · 总结： 这四个都可以用来创建子进程 1. execFile () methods all follow the idiomatic asynchronous programming pattern typical of other Node. spawn () 여기에서는 위 메서드들이 작동하는 방식을 동명의 시스템 콜들과 연관 지어 비교하고자 한다. Understand when to use each method with real-world examples. Sep 24, 2022 · The exec () and spawn () methods are some of the frequently used Node. spawn streams input/output with child process. slfvboopbwyibpkuekvgtgvjcgocvvqsotkutienqeqgyjrxnkifsezpwyrhmoubinulrfdqniqurcwogvi