@johnls/readline-password v1.1.0

Readline for Passwords

• Package: readline-password
  • Class: Interface
  • Event: close
  • Event: SIGINT
  • Method: close()
  • Method: password(options, callback)
  • Method: passwordAsync(options)

Package: readline-password

This is a readline for passwords. It has a similar interface to the Node.js readline. Node's readline does not have any functionality to not echo the output of the question() method to the screen. It also has lots of other functionality such as history and tab completion that is not relevant to entering passwords.

This implementation also provides for optionally echoing the password characters to the screen as *.

Here is an example of the usage:

import readlinePassword from "@johnls/readline-password"

const rl = readlinePassword.createInstance(process.stdin, process.stdout)

rl.on("SIGINT", () => process.exit(1))

rl.password("Password: \u{1F511} ", (password) => {
  console.log(password)
  rl.close()
  process.stdin.unref() // Do this only when we are all done with input
})

You can also use promises:

import readlinePassword from "@johnls/readline-password"

const rl = readlinePassword.createInstance(process.stdin, process.stdout)

rl.on("SIGINT", () => process.exit(1))
;(async () => {
  const password = await rl.passwordAsync("Password: \u{1F511} ")

  console.log(password)
  rl.close()
  process.stdin.unref() // See above
})()

A call to unref() or something similar is needed to cause the Node.js event loop to exit, and is needed even with the built-in readline package.

Class: Interface

Construct with a call to createInterface() or with new Interface().

Event: close

Occurs when:

• The close() method is called

Event: SIGINT

Occurs when:

• The user types Control+C while entering a password

Method: close()

Closes the Interface and relinquishes control over the input and output streams.

Method: password(options, callback)

If options is a string, displays it as the text prompt and begins receiving a password. When the user hits Enter or Return the callback() function is called. This method follows the standard node convention of (err, value) => ... where value is the entered password string. err will always be null. This allows the call to be wrapped with util.promisify().

If options is an object it can contain:

• prompt. String to display for the prompt
• echo. Whether to echo a * everytime an character is entered

The only editing that is supported is Backspace to delete the last character entered, and Control+V or Command+V to paste a password.

Method: passwordAsync(options)

Like password() but returns a Promise.