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# Split (matcher)
[](http://travis-ci.org/dominictarr/split)
Break up a stream and reassemble it so that each line is a chunk. matcher may be a `String`, or a `RegExp`
Example, read every line in a file ...
``` js
fs.createReadStream(file)
.pipe(split())
.on('data', function (line) {
//each chunk now is a separate line!
})
```
`split` takes the same arguments as `string.split` except it defaults to '/\r?\n/' instead of ',', and the optional `limit` parameter is ignored.
[String#split](https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/split)
`split` takes an optional options object on its third argument.
``` js
split(matcher, mapper, options)
```
Valid options:
* maxLength - The maximum buffer length without seeing a newline or `matcher`,
if a single line exceeds this, the split stream will emit an error.
``` js
split(JSON.parse, null, { maxLength: 2})
```
* trailing - By default the last buffer not delimited by a newline or `matcher` will be emitted. To prevent this set `options.trailing` to `false`.
``` js
split(JSON.parse, null, { trailing: false })
```
## keep matched splitter
As with `String#split`, if you split by a regular expression with a matching group,
the matches will be retained in the collection.
```
stdin
.pipe(split(/(\r?\n)/))
... //lines + separators.
```
# NDJ - Newline Delimited Json
`split` accepts a function which transforms each line.
``` js
fs.createReadStream(file)
.pipe(split(JSON.parse))
.on('data', function (obj) {
//each chunk now is a a js object
})
.on('error', function (err) {
//syntax errors will land here
//note, this ends the stream.
})
```
# License
MIT
|
