I have an executable and I want to call it from NodeJS CLI application. This is what I have so far:
var exec = require('child_process').exec;
exec(`./${name_of_executable}`, (err, stdout, stderr) => {
// I want to take user input on which this executable depends on
});
How can I do this?
If you want to pass some arguments you can go with:
const { execFile } = require('child_process');
const child = execFile('node', ['--version'], (error, stdout, stderr) => {
if (error) {
throw error;
}
console.log(stdout);
});
If you want to pass custom stream as standard input to the child process use spawn:
const { spawn } = require('child_process');
// Child will use parent's stdios
spawn('prg', [], { stdio: 'inherit' });
// Spawn child sharing only stderr
spawn('prg', [], { stdio: ['pipe', 'pipe', process.stderr] });
// Open an extra fd=4, to interact with programs presenting a
// startd-style interface.
spawn('prg', [], { stdio: ['pipe', null, null, null, 'pipe'] });
All examples from the docs: https://nodejs.org/api/child_process.html#child_process_options_stdio
node is the name of the file I'd like to execute, and in the [] brackets I put the user arguments. Is that correct?
node --version will be called. If your subprocess requests any data from stdin during execution (e.g. via prompt or readline) you need to glue your subprocess with main process via stdio pipe hooks. It's more complicated than passing command line params, but if you go through the docs, you'll figure it out.
exec()can contain space-separated arguments following the executable name.exec(). The user enters the arguments after the executable file has been called.