66 lines
1.7 KiB
Markdown
66 lines
1.7 KiB
Markdown
# pump
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pump is a small node module that pipes streams together and destroys all of them if one of them closes.
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```
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npm install pump
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```
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[](http://travis-ci.org/mafintosh/pump)
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## What problem does it solve?
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When using standard `source.pipe(dest)` source will _not_ be destroyed if dest emits close or an error.
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You are also not able to provide a callback to tell when then pipe has finished.
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pump does these two things for you
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## Usage
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Simply pass the streams you want to pipe together to pump and add an optional callback
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``` js
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var pump = require('pump')
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var fs = require('fs')
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var source = fs.createReadStream('/dev/random')
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var dest = fs.createWriteStream('/dev/null')
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pump(source, dest, function(err) {
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console.log('pipe finished', err)
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})
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setTimeout(function() {
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dest.destroy() // when dest is closed pump will destroy source
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}, 1000)
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```
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You can use pump to pipe more than two streams together as well
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``` js
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var transform = someTransformStream()
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pump(source, transform, anotherTransform, dest, function(err) {
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console.log('pipe finished', err)
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})
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```
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If `source`, `transform`, `anotherTransform` or `dest` closes all of them will be destroyed.
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Similarly to `stream.pipe()`, `pump()` returns the last stream passed in, so you can do:
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```
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return pump(s1, s2) // returns s2
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```
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If you want to return a stream that combines *both* s1 and s2 to a single stream use
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[pumpify](https://github.com/mafintosh/pumpify) instead.
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## License
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MIT
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## Related
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`pump` is part of the [mississippi stream utility collection](https://github.com/maxogden/mississippi) which includes more useful stream modules similar to this one.
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