how to execute js script file as child process node.js

Question

I have a problem, I'm trying to execute file that sending mail using nodemailer and I need to execute it from another JS file I tried to do it like this:

const  exec  = require('child_process').exec;
       exec('"C:/Users/NikitaSeliverstov/node_modules/.bin/send.js"');

but mail is not sending. I don't need to send params the file send.js just sending text file with fully specified path . Sorry for obvious question but I can't figure it out. Also I tried to do it like this:

 const  exec  = require('child_process').exec;
        exec('"node C:/Users/NikitaSeliverstov/node_modules/.bin/send.js"');

can you show what error you're getting? – Hussain Ali Akbar Dec 11 '18 at 09:40 — Hussain Ali Akbar, Dec 11 '18 at 09:40
I'm not having any err – Nikita Seliverstov Dec 11 '18 at 09:41 — Nikita Seliverstov, Dec 11 '18 at 09:41

score 8 · Accepted Answer · answered Dec 11 '18 at 09:46

8

you need to specify a callback function which will be called after your exec command is executed:

i created 2 files:

anotherTest.js

console.log('another test');

test.js

const exec = require('child_process').exec;

const child = exec('node anotherTest.js',
    (error, stdout, stderr) => {
        console.log(`stdout: ${stdout}`);
        console.log(`stderr: ${stderr}`);
        if (error !== null) {
            console.log(`exec error: ${error}`);
        }
});

this is the output:

stdout: another test

stderr:

you run the test.js script by doing "node test.js" in the terminal/console. you can change the arguments of the exec command with the arguments that you want.

answered Dec 11 '18 at 09:46

Hussain Ali Akbar

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That's works thank you. So the problem is that without callback it won't work? – Nikita Seliverstov Dec 11 '18 at 09:48
1

yup. You need to define a callback function whenever you need to perform an asynchronous operation. Or else, the code wont wait for the operation to complete. – Hussain Ali Akbar Dec 11 '18 at 09:50
1

depending on the node version that you're on, you can replace/wrap callbacks with promises and async await. – Hussain Ali Akbar Dec 11 '18 at 09:50
glad i could help. – Hussain Ali Akbar Dec 11 '18 at 10:00

how to execute js script file as child process node.js

1 Answers1