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- # concat-stream
-
- Writable stream that concatenates all the data from a stream and calls a callback with the result. Use this when you want to collect all the data from a stream into a single buffer.
-
- [![Build Status](https://travis-ci.org/maxogden/concat-stream.svg?branch=master)](https://travis-ci.org/maxogden/concat-stream)
-
- [![NPM](https://nodei.co/npm/concat-stream.png)](https://nodei.co/npm/concat-stream/)
-
- ### description
-
- Streams emit many buffers. If you want to collect all of the buffers, and when the stream ends concatenate all of the buffers together and receive a single buffer then this is the module for you.
-
- Only use this if you know you can fit all of the output of your stream into a single Buffer (e.g. in RAM).
-
- There are also `objectMode` streams that emit things other than Buffers, and you can concatenate these too. See below for details.
-
- ## Related
-
- `concat-stream` is part of the [mississippi stream utility collection](https://github.com/maxogden/mississippi) which includes more useful stream modules similar to this one.
-
- ### examples
-
- #### Buffers
-
- ```js
- var fs = require('fs')
- var concat = require('concat-stream')
-
- var readStream = fs.createReadStream('cat.png')
- var concatStream = concat(gotPicture)
-
- readStream.on('error', handleError)
- readStream.pipe(concatStream)
-
- function gotPicture(imageBuffer) {
- // imageBuffer is all of `cat.png` as a node.js Buffer
- }
-
- function handleError(err) {
- // handle your error appropriately here, e.g.:
- console.error(err) // print the error to STDERR
- process.exit(1) // exit program with non-zero exit code
- }
-
- ```
-
- #### Arrays
-
- ```js
- var write = concat(function(data) {})
- write.write([1,2,3])
- write.write([4,5,6])
- write.end()
- // data will be [1,2,3,4,5,6] in the above callback
- ```
-
- #### Uint8Arrays
-
- ```js
- var write = concat(function(data) {})
- var a = new Uint8Array(3)
- a[0] = 97; a[1] = 98; a[2] = 99
- write.write(a)
- write.write('!')
- write.end(Buffer.from('!!1'))
- ```
-
- See `test/` for more examples
-
- # methods
-
- ```js
- var concat = require('concat-stream')
- ```
-
- ## var writable = concat(opts={}, cb)
-
- Return a `writable` stream that will fire `cb(data)` with all of the data that
- was written to the stream. Data can be written to `writable` as strings,
- Buffers, arrays of byte integers, and Uint8Arrays.
-
- By default `concat-stream` will give you back the same data type as the type of the first buffer written to the stream. Use `opts.encoding` to set what format `data` should be returned as, e.g. if you if you don't want to rely on the built-in type checking or for some other reason.
-
- * `string` - get a string
- * `buffer` - get back a Buffer
- * `array` - get an array of byte integers
- * `uint8array`, `u8`, `uint8` - get back a Uint8Array
- * `object`, get back an array of Objects
-
- If you don't specify an encoding, and the types can't be inferred (e.g. you write things that aren't in the list above), it will try to convert concat them into a `Buffer`.
-
- If nothing is written to `writable` then `data` will be an empty array `[]`.
-
- # error handling
-
- `concat-stream` does not handle errors for you, so you must handle errors on whatever streams you pipe into `concat-stream`. This is a general rule when programming with node.js streams: always handle errors on each and every stream. Since `concat-stream` is not itself a stream it does not emit errors.
-
- We recommend using [`end-of-stream`](https://npmjs.org/end-of-stream) or [`pump`](https://npmjs.org/pump) for writing error tolerant stream code.
-
- # license
-
- MIT LICENSE
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