# pump
pump is a small node module that pipes streams together and destroys all of them if one of them closes.
```
npm install pump
```
[](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.
Similarly to `stream.pipe()`, `pump()` returns the last stream passed in, so you can do:
```
return pump(s1, s2) // returns s2
```
If you want to return a stream that combines *both* s1 and s2 to a single stream use
[pumpify](https://github.com/mafintosh/pumpify) instead.
## 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.
