Hide console's user input after return/new line

Question

What I'd like to do is hiding/erasing all users input from a nodejs console app once entered, so that when the user inserts some text and then types enter, he won't be able to read what he just entered in the console anymore (so basically remove the line right after it's been entered).

This should be pretty simple to achieve but I have no idea how to do it =).

Thank you in advance

EDIT: Let's say we have this code:

const readline = require('readline')

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
 })

rl.question('How ya doin?\n', input => {
    console.log('seems like you\'r doing ' + input.toString())  
})

The app prompts a question
The user answers "Fine" (This line shouldn't be there anymore after the user presses enter)
The program says "seems like .... Fine"

Have you tried this [How to clear console](https://stackoverflow.com/questions/9006988/node-js-on-windows-how-to-clear-console) ? — LEQADA, Jul 17 '17 at 14:59
I don't want to clear the console. I want to clear the user input only (not the program output) — razorxan, Jul 17 '17 at 15:04
Honestly not clear to me what exactly you want to do. Maybe try to explain with example? — LEQADA, Jul 17 '17 at 15:11
Like this `process.stdout.write('\033[1A seems like you\'r doing ' + input.toString());` ? — LEQADA, Jul 17 '17 at 15:44
@TusharGupta I believe the duplicate target is wrong. There is indeed a difference in this question and the one you linked. This one here, wants to clear console *input*, not everything in it. — Félix Adriyel Gagnon-Grenier, Jul 17 '17 at 15:57

score 8 · Answer 1 · answered Jul 18 '17 at 08:05

8

Looks like readline can already handle this for you..

const readline = require('readline')

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
 })

rl.question('How ya doin?\n', input => {
    readline.moveCursor(process.stdout, 0,-1)
    console.log('seems like you\'r doing ' + input.toString())  
})

answered Jul 18 '17 at 08:05

davobutt

161
2

RTM here -> https://nodejs.org/api/readline.html#readline_readline_movecursor_stream_dx_dy – davobutt Jul 18 '17 at 08:06

score 4 · Accepted Answer · edited Jun 20 '20 at 09:12

4

According to Bash HOWTO

Move the cursor up N lines:

\033[<N>A

To overwrite user's 1 line input with your output you should move 1 line up and print your output. It will look like this:

console.log('\033[1A' + 'seems like you\'r doing ' + input.toString());

UPDATE: Found a nice answer :)

How do you edit existing text (and move the cursor around) in the terminal?

edited Jun 20 '20 at 09:12

Community

1
1

answered Jul 17 '17 at 16:13

LEQADA

1,913
3
22
41

It doesn't effect anything to security? i think this way just ANSI color way.. – JaeIL Ryu Nov 26 '21 at 03:37

Hide console's user input after return/new line

2 Answers2