# readline-ui [](https://www.npmjs.com/package/readline-ui) [](https://npmjs.org/package/readline-ui) [](https://npmjs.org/package/readline-ui) [](https://travis-ci.org/enquirer/readline-ui) > Create a readline interface with default settings to use in prompts. ## Install Install with [npm](https://www.npmjs.com/): ```sh $ npm install --save readline-ui ``` ## Usage ```js var UI = require('readline-ui'); var ui = new UI(); ``` ## Example  The following example shows how to create a basic input prompt. This example is a greatly simplified version of [prompt-base](https://github.com/enquirer/prompt-base). _(This code is also in [example.js](example.js) if you want to run it yourself.)_ ```js var cyan = require('ansi-cyan'); var UI = require('readline-ui'); var ui = new UI(); // first, we need to render the "question" // to display in the terminal var prompt = '? foo '; ui.render(prompt); // on keypress events, re-render the prompt // along with user input ui.on('keypress', function() { ui.render(prompt + ui.rl.line); }); // when the "line" event is emitted (from the "enter" keypress) // we `.end()` to unmute the output stream then pause the readline. ui.on('line', function(answer) { ui.render(prompt + cyan(answer)); ui.end(); ui.rl.pause(); console.log({color: answer}); }); ``` ## API ### [.onKeypress](index.js#L70) Handle `keypress` events. **Params** * `str` **{String}** * `key` **{Object}** * `returns` **{undefined}** ### [.render](index.js#L82) Render the prompt with the given `input` and optional `footer`. **Params** * `input` **{String}** * `footer` **{String}**: (optional) * `returns` **{undefined}** ### [.clearLines](index.js#L148) Remove `n` lines from the bottom of the terminal **Params** * `lines` **{Number}**: Number of lines to remove ### [.cacheCursorPos](index.js#L159) Cache the current cursor's column and line position. * `returns` **{Object}**: UI instance. ### [.restoreCursorPos](index.js#L170) Restore the cursor position to the cached column and line. * `returns` **{Object}**: UI instance. ### [.resume](index.js#L180) Resume the input stream. ### [.pause](index.js#L189) Pause the input stream, allowing it to be resumed later if necessary. ### [.close](index.js#L201) Close the `readline.Interface` instance and relinquish control over the input and output streams. Also removes event listeners, and restores/unmutes prompt functionality. ### [.forceClose](index.js#L211) Close the interface when the keypress is `^C` ### [.finish](index.js#L222) Returns an "indentity" function that calls `.close()`, which can be used as the final `.then()` function with promises. ### [.end](index.js#L237) Default method for writing a prompt to the terminal. This can be overridden. ### [.mute](index.js#L260) Mutes the output stream that was used to create the readline interface, and returns a function for unmuting the stream. This is useful in unit tests. * `returns` **{Function}** **Example** ```js // mute the stream var unmute = ui.mute(); // unmute the stream unmute(); ``` ### [.log](index.js#L280) Unmute then write to the output stream that was used to create the readline interface, then re-mute the stream. Useful for debugging prompts. ## Attribution Inspired by the "screen manager" code in Inquirer. ## About ### Related projects * [enquirer](https://www.npmjs.com/package/enquirer): Intuitive, plugin-based prompt system for node.js. | [homepage](http://enquirer.io "Intuitive, plugin-based prompt system for node.js.") * [prompt-choices](https://www.npmjs.com/package/prompt-choices): Create an array of multiple choice objects for use in prompts. | [homepage](https://github.com/enquirer/prompt-choices "Create an array of multiple choice objects for use in prompts.") * [prompt-question](https://www.npmjs.com/package/prompt-question): Question object, used by Enquirer and prompt plugins. | [homepage](https://github.com/enquirer/prompt-question "Question object, used by Enquirer and prompt plugins.") * [readline-utils](https://www.npmjs.com/package/readline-utils): Readline utils, for moving the cursor, clearing lines, creating a readline interface, and more. | [homepage](https://github.com/enquirer/readline-utils "Readline utils, for moving the cursor, clearing lines, creating a readline interface, and more.") ### Contributing Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](../../issues/new). Please read the [contributing guide](.github/contributing.md) for advice on opening issues, pull requests, and coding standards. ### Building docs _(This project's readme.md is generated by [verb](https://github.com/verbose/verb-generate-readme), please don't edit the readme directly. Any changes to the readme must be made in the [.verb.md](.verb.md) readme template.)_ To generate the readme, run the following command: ```sh $ npm install -g verbose/verb#dev verb-generate-readme && verb ``` ### Running tests Running and reviewing unit tests is a great way to get familiarized with a library and its API. You can install dependencies and run tests with the following command: ```sh $ npm install && npm test ``` ### Author **Jon Schlinkert** * [github/jonschlinkert](https://github.com/jonschlinkert) * [twitter/jonschlinkert](https://twitter.com/jonschlinkert) ### License Copyright © 2017, [Jon Schlinkert](https://github.com/jonschlinkert). Released under the [MIT License](LICENSE). *** _This file was generated by [verb-generate-readme](https://github.com/verbose/verb-generate-readme), v0.6.0, on June 04, 2017._