From 781290b61d7194e142526cc22fb24abeaf82153e Mon Sep 17 00:00:00 2001 From: Robert Jefe Lindstaedt Date: Fri, 19 Feb 2016 21:17:24 +0100 Subject: [PATCH] doc: refine child_process detach behaviour this adds an example of a long running node process that actually executes node code. Also it mentions the not to harmonic detach behaviours of the different platforms, whereas detaching on unix requires ignoring the child_process' stdio explicitely. PR-URL: https://github.com/nodejs/node/pull/5330 Reviewed-By: Colin Ihrig Reviewed-By: James M Snell --- doc/api/child_process.markdown | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-) diff --git a/doc/api/child_process.markdown b/doc/api/child_process.markdown index c4be598ecd9ab2..ae0b8ac9ed0afb 100644 --- a/doc/api/child_process.markdown +++ b/doc/api/child_process.markdown @@ -405,8 +405,27 @@ Doing so will cause the parent's event loop to not include the child in its reference count, allowing the parent to exit independently of the child, unless there is an established IPC channel between the child and parent. -Example of detaching a long-running process and redirecting its output to a -file: +When using the `detached` option to start a long-running process, the process +will not stay running in the background after the parent exits unless it is +provided with a `stdio` configuration that is not connected to the parent. +If the parent's `stdio` is inherited, the child will remain attached to the +controlling terminal. + +Example of a long-running process, by detaching and also ignoring its parent +`stdio` file descriptors, in order to ignore the parent's termination: + +```js +const spawn = require('child_process').spawn; + +const child = spawn(process.argv[0], ['child_program.js'], { + detached: true, + stdio: ['ignore'] +}); + +child.unref(); +``` + +Alternatively one can redirect the child process' output into files: ```js const fs = require('fs'); @@ -422,12 +441,6 @@ const child = spawn('prg', [], { child.unref(); ``` -When using the `detached` option to start a long-running process, the process -will not stay running in the background after the parent exits unless it is -provided with a `stdio` configuration that is not connected to the parent. -If the parent's `stdio` is inherited, the child will remain attached to the -controlling terminal. - #### options.stdio The `options.stdio` option is used to configure the pipes that are established