process.exit([code])

• code <integer> 退出码。 默认值: 0。

process.exit() 方法指示 Node.js 以 code 的退出状态同步终止进程。 如果省略 code，则退出将使用“成功”代码 0 或 process.exitCode 的值（如果已设置）。 直到所有 'exit' 事件监听器都被调用，Node.js 才会终止。

以“失败”代码退出：

import { exit } from 'node:process';

exit(1);const { exit } = require('node:process');

exit(1);

执行 Node.js 的 shell 应该看到退出码为 1。

调用 process.exit() 将强制进程尽快退出，即使仍有未完全完成的异步操作挂起，包括对 process.stdout 和 process.stderr 的 I/O 操作。

在大多数情况下，实际上没有必要显式调用 process.exit()。 如果事件循环中没有其他待处理的工作，则 Node.js 进程将自行退出。 可以设置 process.exitCode 属性来告诉进程在进程正常退出时使用哪个退出码。

例如，以下示例说明了 process.exit() 方法的误用，其可能导致打印到标准输出的数据被截断和丢失：

import { exit } from 'node:process';

// 这是不该做的示例：
if (someConditionNotMet()) {
  printUsageToStdout();
  exit(1);
}const { exit } = require('node:process');

// 这是不该做的示例：
if (someConditionNotMet()) {
  printUsageToStdout();
  exit(1);
}

这是有问题的原因是因为在 Node.js 中写入 process.stdout 有时是异步的，并且可能发生在 Node.js 事件循环的多个滴答上。 但是，调用 process.exit() 会强制进程在执行对 stdout 的其他写入之前退出。

代码应该设置 process.exitCode 并通过避免为事件循环安排任何额外工作来允许进程自然退出，而不是直接调用 process.exit()：

import process from 'node:process';

// 如何正确设置退出码，同时让进程正常退出。
if (someConditionNotMet()) {
  printUsageToStdout();
  process.exitCode = 1;
}const process = require('node:process');

// 如何正确设置退出码，同时让进程正常退出。
if (someConditionNotMet()) {
  printUsageToStdout();
  process.exitCode = 1;
}

如果由于错误情况需要终止 Node.js 进程，则抛出未捕获的错误并允许进程相应地终止比调用 process.exit() 更安全。

在 Worker 线程中，该函数停止当前线程而不是当前进程。

• code <integer> The exit code. Default: 0.

The process.exit() method instructs Node.js to terminate the process synchronously with an exit status of code. If code is omitted, exit uses either the 'success' code 0 or the value of process.exitCode if it has been set. Node.js will not terminate until all the 'exit' event listeners are called.

To exit with a 'failure' code:

import { exit } from 'node:process';

exit(1);const { exit } = require('node:process');

exit(1);

The shell that executed Node.js should see the exit code as 1.

Calling process.exit() will force the process to exit as quickly as possible even if there are still asynchronous operations pending that have not yet completed fully, including I/O operations to process.stdout and process.stderr.

In most situations, it is not actually necessary to call process.exit() explicitly. The Node.js process will exit on its own if there is no additional work pending in the event loop. The process.exitCode property can be set to tell the process which exit code to use when the process exits gracefully.

For instance, the following example illustrates a misuse of the process.exit() method that could lead to data printed to stdout being truncated and lost:

import { exit } from 'node:process';

// This is an example of what *not* to do:
if (someConditionNotMet()) {
  printUsageToStdout();
  exit(1);
}const { exit } = require('node:process');

// This is an example of what *not* to do:
if (someConditionNotMet()) {
  printUsageToStdout();
  exit(1);
}

The reason this is problematic is because writes to process.stdout in Node.js are sometimes asynchronous and may occur over multiple ticks of the Node.js event loop. Calling process.exit(), however, forces the process to exit before those additional writes to stdout can be performed.

Rather than calling process.exit() directly, the code should set the process.exitCode and allow the process to exit naturally by avoiding scheduling any additional work for the event loop:

import process from 'node:process';

// How to properly set the exit code while letting
// the process exit gracefully.
if (someConditionNotMet()) {
  printUsageToStdout();
  process.exitCode = 1;
}const process = require('node:process');

// How to properly set the exit code while letting
// the process exit gracefully.
if (someConditionNotMet()) {
  printUsageToStdout();
  process.exitCode = 1;
}

If it is necessary to terminate the Node.js process due to an error condition, throwing an uncaught error and allowing the process to terminate accordingly is safer than calling process.exit().

In Worker threads, this function stops the current thread rather than the current process.