From 37ed05b8c154fbd1c2afd02c603ebb48b8527232 Mon Sep 17 00:00:00 2001 From: Rich Trott Date: Mon, 7 Dec 2015 19:31:38 -0800 Subject: [PATCH] doc: copyedit child_process doc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit PR-URL: https://github.com/nodejs/node/pull/4188 Reviewed-By: Michaël Zasso Reviewed-By: Minwoo Jung --- doc/api/child_process.markdown | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-) diff --git a/doc/api/child_process.markdown b/doc/api/child_process.markdown index 322add74f46b81..e9e4b3711cbf72 100644 --- a/doc/api/child_process.markdown +++ b/doc/api/child_process.markdown @@ -10,9 +10,9 @@ It is possible to stream data through a child's `stdin`, `stdout`, and line-buffered I/O internally. That doesn't affect Node.js but it means data you send to the child process may not be immediately consumed.) -To create a child process use `require('child_process').spawn()` or +To create a child process, use `require('child_process').spawn()` or `require('child_process').fork()`. The semantics of each are slightly -different, and explained [below][]. +different as explained [below][]. For scripting purposes you may find the [synchronous counterparts][] more convenient. @@ -54,11 +54,11 @@ Emitted when: 1. The process could not be spawned, or 2. The process could not be killed, or -3. Sending a message to the child process failed for whatever reason. +3. Sending a message to the child process failed. -Note that the `'exit'` event may or may not fire after an error has occurred. If -you are listening on both events to fire a function, remember to guard against -calling your function twice. +Note that the `'exit'` event may or may not fire after an error has occurred. +If you are listening on both events to fire a function, remember to guard +against calling your function twice. See also [`ChildProcess#kill()`][] and [`ChildProcess#send()`][]. @@ -76,8 +76,7 @@ of the signal, otherwise `null`. Note that the child process stdio streams might still be open. Also, note that Node.js establishes signal handlers for `SIGINT` and -`SIGTERM`, so it will not terminate due to receipt of those signals, -it will exit. +`SIGTERM`. It will not terminate due to receipt of those signals. It will exit. See `waitpid(2)`. @@ -103,8 +102,8 @@ gracefully once there are no other connections keeping it alive. After calling this method the `.connected` flag will be set to `false` in both the parent and child, and it is no longer possible to send messages. -The `'disconnect'` event will be emitted when there are no messages in the process -of being received, most likely immediately. +The `'disconnect'` event will be emitted when there are no messages in the +process of being received, most likely immediately. Note that you can also call `process.disconnect()` in the child process when the child process has any open IPC channels with the parent (i.e [`fork()`][]). @@ -128,9 +127,9 @@ be sent `'SIGTERM'`. See `signal(7)` for a list of available signals. May emit an `'error'` event when the signal cannot be delivered. Sending a signal to a child process that has already exited is not an error but may -have unforeseen consequences: if the PID (the process ID) has been reassigned -to another process, the signal will be delivered to that process instead. -What happens next is anyone's guess. +have unforeseen consequences. Specifically, if the process identifier (PID) has +been reassigned to another process, the signal will be delivered to that +process instead. What happens next is anyone's guess. Note that while the function is called `kill`, the signal delivered to the child process may not actually kill it. `kill` really just sends a signal @@ -142,7 +141,7 @@ See `kill(2)` * {Integer} -The PID of the child process. +The process identifier (PID) of the child process. Example: @@ -183,7 +182,7 @@ And then the child script, `'sub.js'` might look like this: process.send({ foo: 'bar' }); -In the child the `process` object will have a `send()` method, and `process` +In the child, the `process` object will have a `send()` method, and `process` will emit objects each time it receives a message on its channel. There is a special case when sending a `{cmd: 'NODE_foo'}` message. All messages