What is foreground-child?
The foreground-child npm package is used to run a child process in the foreground, ensuring that signals such as SIGINT, SIGTERM, and exit codes are properly forwarded from the child process to the parent. This is particularly useful when you want to ensure that a child process is treated as if it were the main process, especially in the context of command-line tools and scripts.
What are foreground-child's main functionalities?
Running a child process in the foreground
This feature allows you to run a child process as if it were the main process. The code sample demonstrates how to use foreground-child to run a Node.js script in the foreground.
const foregroundChild = require('foreground-child');
const cmd = 'node';
const args = ['my-script.js'];
foregroundChild(cmd, args);
Other packages similar to foreground-child
cross-spawn
cross-spawn is a cross-platform solution for spawning child processes with support for handling command line arguments properly. It is similar to foreground-child in that it deals with child processes, but it does not specifically focus on running them in the foreground.
execa
execa is a wrapper for child_process methods that provides a more user-friendly API. It supports synchronous and asynchronous execution of child processes and also allows for running processes in the foreground, similar to foreground-child, but with additional features such as promise support and result parsing.
child-process-promise
child-process-promise provides promise-based wrappers for the child_process module. While it simplifies working with asynchronous child processes, it does not have a specific focus on running child processes in the foreground like foreground-child does.
foreground-child
Run a child as if it's the foreground process. Give it stdio. Exit
when it exits.
Mostly this module is here to support some use cases around wrapping
child processes for test coverage and such.
USAGE
var foreground = require('foreground-child')
var child = foreground('cat', [__filename])
A callback can optionally be provided, if you want to perform an action
before your foreground-child exits:
var child = foreground('cat', [__filename], function (done) {
return done()
})
Caveats
The "normal" standard IO file descriptors (0, 1, and 2 for stdin,
stdout, and stderr respectively) are shared with the child process.
Additionally, if there is an IPC channel set up in the parent, then
messages are proxied to the child on file descriptor 3.
However, in Node, it's possible to also map arbitrary file descriptors
into a child process. In these cases, foreground-child will not map
the file descriptors into the child. If file descriptors 0, 1, or 2
are used for the IPC channel, then strange behavior may happen (like
printing IPC messages to stderr, for example).