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pump

Tom Santiago
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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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Problems resolved by pump

When using standard source.pipe(dest) source will not be destroyed if dest emits close or an error. You are also unable to provide a callback to tell when then pipe has finished. pump does these two things for you.

Install pump

Using npm:

npm install pump

External links

pump usage

Pass the streams you want to pipe together to pump and add an optional callback.

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.

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
Notes:
  • pump attaches error handlers to the streams to do internal error handling, so if s2 emits an error in the above scenario, it will not trigger a proccess.on('uncaughtException') if you do not listen for it.
  • If you want to return a stream that combines both s1 and s2 to a single stream, use pumpify instead.

pump license

MIT

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