how can I use a callback tor a promise correctly to get the result from a node exec in the condole.log()
function?
import { exec } from 'child_process';
const check = () => {
exec(`...`, (err, stdout) => {
if (err) {
return false
}
else {
return true
}
})
}
console.log(check()) // getting undefined
I've tried using .on('exit')
but none worked... would love to get some help here. THANKS!!
You can either use the Promise constructor to do it yourself or you can use the util module to convert a callback invoking function into one that returns a promise
Using the util module
const util = require("util");
const exec = util.promisify(require("child_process").exec);
const check = async () => {
const output = await exec(`echo hi`);
console.log(output);
};
check();
Wrapping with the Promise constructor
import { exec } from "child_process";
const check = async () => {
return new Promise((resolve, reject) => {
exec(`echo hi`, (err, stdout) => {
if (err) {
reject(err);
} else {
resolve(stdout);
}
});
});
};