qrcode-terminal

To use qrcode-terminal as a standalone command-line tool, install it globally with npm:

npm install -g qrcode-terminal

$ npm install -g qrcode-terminal

Import the library using require('qrcode-terminal'). You can generate QR codes directly to the terminal, set error correction levels, or capture the QR code as a string via a callback.

var qrcode = require('qrcode-terminal');

// Basic usage: displays to terminal
qrcode.generate('This will be a QRCode, eh!');

// Set error level (default is 'L')
qrcode.setErrorLevel('Q');
qrcode.generate('This will be a QRCode with error level Q!');

// Get QR code as a string via callback (does not display to terminal)
qrcode.generate('http://github.com', function (qrcode) {
    console.log(qrcode);
});

// Small output mode
qrcode.generate('This will be a small QRCode, eh!', {small: true});

// Small output mode with callback
qrcode.generate('This will be a small QRCode, eh!', {small: true}, function (qrcode) {
    console.log(qrcode);
});

To use qrcode-terminal as a Node.js library in your project, install it using npm:

npm install qrcode-terminal

$ npm install qrcode-terminal

The generate(input, opts, cb) method creates a QR code from the provided input string and outputs it to the terminal or via a callback.

Parameters:

• input (string): The data to encode in the QR code.
• opts (object, optional): Configuration options.
  • small (boolean): If true, uses special Unicode block characters (█, ▀, ▄) to render a more compact QR code. If false (default), uses ANSI color codes for a standard block output.
• cb (function, optional): A callback function that receives the generated string output. If no callback is provided, the output is printed directly to console.log.

Behavior:

• If opts is omitted, it defaults to an empty object.
• If opts is passed as a function, it is treated as the callback cb.

The setErrorLevel(error) method sets the error correction level for subsequent generate() calls. It uses levels defined in the internal QRErrorCorrectLevel mapping.

Parameters:

• error (string): The name of the error correction level. If the provided string does not match a valid level, the current level is retained.

Note: The default error level is QRErrorCorrectLevel.L.

The following flags and arguments are supported by the qrcode-terminal command-line interface:

Usage: qrcode-terminal <message>

Options:
  -h, --help           output usage information
  -v, --version        output version number