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Questions tagged [child-process]

For questions regarding child-process

In Unix, a child process is typically created as a copy of the parent, using the fork system call. The child process can then overlay itself with a different program (using exec) as required.

Each process may create many child processes but will have at most one parent process; if a process does not have a parent this usually indicates that it was created directly by the kernel.

The inter communication between a child process and a parent process can be done through normal communication schemes such as pipes, sockets, message queues, shared memories.

When a child process terminates, some information is returned to the parent process. When a child process terminates before the parent has called wait, the kernel retains some information about the process, such as its exit status, to enable its parent to call wait later

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child_process.fork not starting an express server inside of packaged electron app

I have an electron app where I need not only to run the interface to the user but also start an express server that will serve files for people connected through the network. I have everything working if I start both electron and the express server…
Victor Ivens
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Spawning a child process with tty in node.js

I am trying to do some work on a remote server using ssh--and ssh is called on the local machine from node.js A stripped down version of the script looks like this: var execSync = require("child_process").execSync; var command = 'ssh -qt…
user1739757
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Node.js: child_process.spawn no output standard output unless 'inherit'

I'm trying to capture standard output from a spawned child_process in Node.js (0.10.29). Right now I'm just trying with ping. The following code doesn't print (but does ping) var exec = require('child_process').exec; var spawn =…
dbenny
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Find all child processes of my own .NET process / find out if a given process is a child of my own?

I have a .NET class library that spins up a secondary process which is kept running until I dispose of the object. Due to some occurances of the program lingering in memory, I've decided to add an integration test to ensure that if I let the object…
Lasse V. Karlsen
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bash: Why can't I set a trap for SIGINT in a background shell?

Here's a simple program that registers two trap handlers and then displays them with trap -p. Then it does the same thing, but in a child background process. Why does the background process ignore the SIGINT trap? #!/bin/bash echo "Traps on…
Stuart Berg
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Using a pipe character | with child_process spawn

I'm running nodejs on a raspberry pi and I want to run a child process to spawn a webcam stream. Outside of node my command is: raspivid -n -mm matrix -w 320 -h 240 -fps 18 -g 100 -t 0 -b 5000000 -o - | ffmpeg -y -f h264 -i - -c:v copy -map 0:0 -f…
Titan
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Stream stdout from child process to browser via expressjs

We have an app built using nodejs, express and child_process.spawn. One requirement is that we need to spawn a process at runtime and capture it's output and present it to the user. We have that working. However, we need to figure out a way to…
user2787799
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Using SSH over Node.js

I'm trying to run a ssh child process in node.js and control it through my program. My code: var util = require('util'); var spawn = require('child_process').spawn; var ssh = spawn('ssh', ['cloudstudios.ch']); ssh.stdout.on('data', function…
Van Coding
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Detach child process from parent

When a child process forked from a parent dies, it still exists to some extent and is left in a zombie state, until it is reaped from a wait() call. Is is possible to detach this parent-child relationship and have the children be automatically…
Shaggi
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Node.js - Sending a big object to child_process is slow

My Use-case is as follows: I make plenty of rest API calls from my node server to public APIs. Sometime the response is big and sometimes its small. My use-case demands me to stringify the response JSON. I know a big JSON as response is going to…
Vinoth
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spawning node.js child processes results in zombie processes on cloud foundry

I have a node.js app, and I want to spawn child processes using the code listed below. When I run this app locally, each of the 'ps' commands nicely trigger the close and exit events. On our cloud foundry (pivotal.io) app however, the stdout.close…
mweststrate
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How to stream to/from a file descriptor in node?

The fs.createReadStream() and fs.createWriteStream() only support file paths but I need to read (or write) from a file descriptor (passed to/from a child process). Note I need Streams, so fs.open/fs.read/fs.write are not sufficient.
Bartvds
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Stdout of Node.js child_process exec is cut short

In Node.js I'm using the exec command of the child_process module to call an algorithm in Java that returns a large amount of text to standard out which I then parse and use. I'm able to capture it mostly, but when it exceeds a certain number of…
Alex H Hadik
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how to get a child process memory usage in node.js?

I know there is a api process.memoryUsage() to get memory usage in current process. But if I start a new child process by child_process.spawn(command, [args], [options]) and I get a ChildProcess object, then how can I get the new process memory…
CALL ME TZ
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Sklearn Model (Python) with NodeJS (Express): how to connect both?

I have a web server using NodeJS - Express and I have a Scikit-Learn (machine learning) model pickled (dumped) in the same machine. What I need is to demonstrate the model by sending/receiving data from it to the server. I want to load the model on…
Jean Phelippe
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