Flexible ascii progress bar.
$ npm install progress
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);
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 completesThese 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 secondYou 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!
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
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.
MIT