@stdlib/streams-node-stdin

What is @stdlib/streams-node-stdin?

@stdlib/streams-node-stdin is a package that provides utilities for working with standard input (stdin) streams in Node.js. It allows you to read data from stdin in various ways, making it easier to handle input in command-line applications.

What are @stdlib/streams-node-stdin's main functionalities?

Read entire stdin as a string

This feature allows you to read the entire stdin input as a single string. The callback function receives the data once it has been fully read.

const stdin = require('@stdlib/streams-node-stdin');

stdin(function (error, data) {
  if (error) {
    console.error('Error reading stdin:', error);
    return;
  }
  console.log('Data:', data);
});

Read stdin line-by-line

This feature allows you to read stdin input line-by-line. Each line is emitted as a 'data' event, making it easy to process input incrementally.

const stdin = require('@stdlib/streams-node-stdin');

stdin.lineStream().on('data', function (line) {
  console.log('Line:', line);
});

Read stdin as a stream

This feature allows you to read stdin as a stream of data chunks. Each chunk is emitted as a 'data' event, which can be useful for processing large inputs incrementally.

const stdin = require('@stdlib/streams-node-stdin');

const stream = stdin.stream();
stream.on('data', function (chunk) {
  console.log('Chunk:', chunk.toString());
});

Other packages similar to @stdlib/streams-node-stdin

readline

The 'readline' module in Node.js provides an interface for reading data from a Readable stream (such as process.stdin) one line at a time. It is part of the Node.js standard library and offers similar functionality to @stdlib/streams-node-stdin for line-by-line input processing.

get-stdin

The 'get-stdin' package is a simple utility for getting stdin as a string or buffer. It is similar to @stdlib/streams-node-stdin's functionality for reading the entire stdin input at once.

split

The 'split' package is a transform stream that splits data on a delimiter, such as a newline character. It can be used to process stdin line-by-line, similar to the lineStream feature of @stdlib/streams-node-stdin.

README

About stdlib...

We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.

The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.

When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.

To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!

Standard Input

Standard input.

Installation

npm install @stdlib/streams-node-stdin

Usage

var stdin = require( '@stdlib/streams-node-stdin' );

stdin

Standard input as a Readable stream.

var string2buffer = require( '@stdlib/buffer-from-string' );
var Buffer = require( '@stdlib/buffer-ctor' );

var data = [];
var len = 0;

stdin.on( 'readable', onReadable );
stdin.on( 'error', onError );
stdin.on( 'end', onEnd );

function onReadable() {
    var chunk;
    while ( true ) {
        chunk = stdin.read();
        if ( chunk === null ) {
            break;
        }
        if ( typeof chunk === 'string' ) {
            chunk = string2buffer( chunk );
        }
        data.push( chunk );
        len += chunk.length;
    }
}

function onError( error ) {
    if ( error ) {
        console.error( error.message );
    }
}

function onEnd() {
    data = Buffer.concat( data, len );
    console.log( data.toString() );
    // => '...'
}

Examples

var proc = require( 'process' );
var stdin = require( '@stdlib/streams-node-stdin' );
var stdout = require( '@stdlib/streams-node-stdout' );

// Set the encoding:
stdin.setEncoding( 'utf8' );

// Create an echo stream:
stdin.pipe( stdout );

// Push data to `stdin`:
stdin.push( 'beep' );
stdin.push( ' ' );
stdin.push( 'boop' );
stdin.push( '\n' );

// End the stream:
stdin.push( null );

// Ensure the process closes:
setTimeout( proc.exit, 1000 );

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Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

Community

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License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.

Changelog

0.2.1 (2024-02-21)

No changes reported for this release.

</section> <!-- /.release --> <section class="release" id="v0.2.0">