What is progress?
The 'progress' npm package is used to create a flexible text progress bar in the console. It is useful for tracking the progress of an operation in command-line applications.
What are progress's main functionalities?
Basic Progress Bar
This code sample demonstrates how to create a simple progress bar that updates every 100 milliseconds until it's complete.
const ProgressBar = require('progress');
let bar = new ProgressBar(':bar', { total: 10 });
let timer = setInterval(() => {
bar.tick();
if (bar.complete) {
console.log('\nComplete!');
clearInterval(timer);
}
}, 100);
Custom Tokens
This code sample shows how to use custom tokens within the progress bar format to display additional information.
const ProgressBar = require('progress');
let bar = new ProgressBar(':current/:total (:percent) :bar :custom', { total: 20, width: 30 });
bar.tick({ custom: 'Token' });
Increment with Step
This code sample illustrates how to increment the progress bar by a step greater than one.
const ProgressBar = require('progress');
let bar = new ProgressBar(':bar', { total: 10 });
bar.tick(2);
Other packages similar to progress
cli-progress
cli-progress is a full-featured progress bar for Node.js command line applications. It offers more customization options than 'progress', such as multiple bars, custom bar characters, and payload handling.
nanobar
nanobar is a very lightweight progress bar without jQuery. While it is not directly comparable to 'progress' since it's for browser use, it serves a similar purpose in providing visual feedback for progress in a minimalistic way.
node-progress-bars
node-progress-bars is another alternative to 'progress' that allows for multiple simultaneous progress bars in the terminal. It provides a different API and additional features like color support.
Flexible ascii progress bar.
Installation
$ npm install progress
Usage
First we create a ProgressBar
, giving it a format string
as well as the total
, telling the progress bar when it will
be considered complete. After that all we need to do is tick()
appropriately.
var ProgressBar = require('progress');
var bar = new ProgressBar(':bar', { total: 10 });
var timer = setInterval(function () {
bar.tick();
if (bar.complete) {
console.log('\ncomplete\n');
clearInterval(timer);
}
}, 100);
Options
These are keys in the options object you can pass to the progress bar along with
total
as seen in the example above.
curr
current completed indextotal
total number of ticks to completewidth
the displayed width of the progress bar defaulting to totalstream
the output stream defaulting to stderrhead
head character defaulting to complete charactercomplete
completion character defaulting to "="incomplete
incomplete character defaulting to "-"renderThrottle
minimum time between updates in milliseconds defaulting to 16clear
option to clear the bar on completion defaulting to falsecallback
optional function to call when the progress bar completes
Tokens
These are tokens you can use in the format of your progress bar.
:bar
the progress bar itself:current
current tick number:total
total ticks:elapsed
time elapsed in seconds:percent
completion percentage:eta
estimated completion time in seconds:rate
rate of ticks per second
Custom Tokens
You can define custom tokens by adding a {'name': value}
object parameter to your method (tick()
, update()
, etc.) calls.
var bar = new ProgressBar(':current: :token1 :token2', { total: 3 })
bar.tick({
'token1': "Hello",
'token2': "World!\n"
})
bar.tick(2, {
'token1': "Goodbye",
'token2': "World!"
})
The above example would result in the output below.
1: Hello World!
3: Goodbye World!
Examples
Download
In our download example each tick has a variable influence, so we pass the chunk
length which adjusts the progress bar appropriately relative to the total
length.
var ProgressBar = require('progress');
var https = require('https');
var req = https.request({
host: 'download.github.com',
port: 443,
path: '/visionmedia-node-jscoverage-0d4608a.zip'
});
req.on('response', function(res){
var len = parseInt(res.headers['content-length'], 10);
console.log();
var bar = new ProgressBar(' downloading [:bar] :rate/bps :percent :etas', {
complete: '=',
incomplete: ' ',
width: 20,
total: len
});
res.on('data', function (chunk) {
bar.tick(chunk.length);
});
res.on('end', function () {
console.log('\n');
});
});
req.end();
The above example result in a progress bar like the one below.
downloading [===== ] 39/bps 29% 3.7s
Interrupt
To display a message during progress bar execution, use interrupt()
var ProgressBar = require('progress');
var bar = new ProgressBar(':bar :current/:total', { total: 10 });
var timer = setInterval(function () {
bar.tick();
if (bar.complete) {
clearInterval(timer);
} else if (bar.curr === 5) {
bar.interrupt('this message appears above the progress bar\ncurrent progress is ' + bar.curr + '/' + bar.total);
}
}, 1000);
You can see more examples in the examples
folder.
License
MIT