tra-analysis/website/functions/node_modules/pump/README.md

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2019-01-06 19:14:45 +00:00
# pump
pump is a small node module that pipes streams together and destroys all of them if one of them closes.
```
npm install pump
```
[![build status](http://img.shields.io/travis/mafintosh/pump.svg?style=flat)](http://travis-ci.org/mafintosh/pump)
## What problem does it solve?
When using standard `source.pipe(dest)` source will _not_ be destroyed if dest emits close or an error.
You are also not able to provide a callback to tell when then pipe has finished.
pump does these two things for you
## Usage
Simply pass the streams you want to pipe together to pump and add an optional callback
``` js
var pump = require('pump')
var fs = require('fs')
var source = fs.createReadStream('/dev/random')
var dest = fs.createWriteStream('/dev/null')
pump(source, dest, function(err) {
console.log('pipe finished', err)
})
setTimeout(function() {
dest.destroy() // when dest is closed pump will destroy source
}, 1000)
```
You can use pump to pipe more than two streams together as well
``` js
var transform = someTransformStream()
pump(source, transform, anotherTransform, dest, function(err) {
console.log('pipe finished', err)
})
```
If `source`, `transform`, `anotherTransform` or `dest` closes all of them will be destroyed.
## License
MIT
## Related
`pump` is part of the [mississippi stream utility collection](https://github.com/maxogden/mississippi) which includes more useful stream modules similar to this one.