# send

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Send is a library for streaming files from the file system as a http response
supporting partial responses (Ranges), conditional-GET negotiation, high test
coverage, and granular events which may be leveraged to take appropriate actions
in your application or framework.

Looking to serve up entire folders mapped to URLs? Try [serve-static](https://www.npmjs.org/package/serve-static).

## Installation

This is a [Node.js](https://nodejs.org/en/) module available through the
[npm registry](https://www.npmjs.com/). Installation is done using the
[`npm install` command](https://docs.npmjs.com/getting-started/installing-npm-packages-locally):

```bash
$ npm install send
```

## API

```js
var send = require('send')
```

### send(req, path, [options])

Create a new `SendStream` for the given path to send to a `res`. The `req` is
the Node.js HTTP request and the `path` is a urlencoded path to send (urlencoded,
not the actual file-system path).

#### Options

##### acceptRanges

Enable or disable accepting ranged requests, defaults to true.
Disabling this will not send `Accept-Ranges` and ignore the contents
of the `Range` request header.

##### cacheControl

Enable or disable setting `Cache-Control` response header, defaults to
true. Disabling this will ignore the `maxAge` option.

##### dotfiles

Set how "dotfiles" are treated when encountered. A dotfile is a file
or directory that begins with a dot ("."). Note this check is done on
the path itself without checking if the path actually exists on the
disk. If `root` is specified, only the dotfiles above the root are
checked (i.e. the root itself can be within a dotfile when when set
to "deny").

  - `'allow'` No special treatment for dotfiles.
  - `'deny'` Send a 403 for any request for a dotfile.
  - `'ignore'` Pretend like the dotfile does not exist and 404.

The default value is _similar_ to `'ignore'`, with the exception that
this default will not ignore the files within a directory that begins
with a dot, for backward-compatibility.

##### end

Byte offset at which the stream ends, defaults to the length of the file
minus 1. The end is inclusive in the stream, meaning `end: 3` will include
the 4th byte in the stream.

##### etag

Enable or disable etag generation, defaults to true.

##### extensions

If a given file doesn't exist, try appending one of the given extensions,
in the given order. By default, this is disabled (set to `false`). An
example value that will serve extension-less HTML files: `['html', 'htm']`.
This is skipped if the requested file already has an extension.

##### index

By default send supports "index.html" files, to disable this
set `false` or to supply a new index pass a string or an array
in preferred order.

##### lastModified

Enable or disable `Last-Modified` header, defaults to true. Uses the file
system's last modified value.

##### maxAge

Provide a max-age in milliseconds for http caching, defaults to 0.
This can also be a string accepted by the
[ms](https://www.npmjs.org/package/ms#readme) module.

##### root

Serve files relative to `path`.

##### start

Byte offset at which the stream starts, defaults to 0. The start is inclusive,
meaning `start: 2` will include the 3rd byte in the stream.

#### Events

The `SendStream` is an event emitter and will emit the following events:

  - `error` an error occurred `(err)`
  - `directory` a directory was requested
  - `file` a file was requested `(path, stat)`
  - `headers` the headers are about to be set on a file `(res, path, stat)`
  - `stream` file streaming has started `(stream)`
  - `end` streaming has completed

#### .pipe

The `pipe` method is used to pipe the response into the Node.js HTTP response
object, typically `send(req, path, options).pipe(res)`.

### .mime

The `mime` export is the global instance of of the
[`mime` npm module](https://www.npmjs.com/package/mime).

This is used to configure the MIME types that are associated with file extensions
as well as other options for how to resolve the MIME type of a file (like the
default type to use for an unknown file extension).

## Error-handling

By default when no `error` listeners are present an automatic response will be
made, otherwise you have full control over the response, aka you may show a 5xx
page etc.

## Caching

It does _not_ perform internal caching, you should use a reverse proxy cache
such as Varnish for this, or those fancy things called CDNs. If your
application is small enough that it would benefit from single-node memory
caching, it's small enough that it does not need caching at all ;).

## Debugging

To enable `debug()` instrumentation output export __DEBUG__:

```
$ DEBUG=send node app
```

## Running tests

```
$ npm install
$ npm test
```

## Examples

### Small example

```js
var http = require('http')
var parseUrl = require('parseurl')
var send = require('send')

var app = http.createServer(function onRequest (req, res) {
  send(req, parseUrl(req).pathname).pipe(res)
}).listen(3000)
```

### Custom file types

```js
var http = require('http')
var parseUrl = require('parseurl')
var send = require('send')

// Default unknown types to text/plain
send.mime.default_type = 'text/plain'

// Add a custom type
send.mime.define({
  'application/x-my-type': ['x-mt', 'x-mtt']
})

var app = http.createServer(function onRequest (req, res) {
  send(req, parseUrl(req).pathname).pipe(res)
}).listen(3000)
```

### Serving from a root directory with custom error-handling

```js
var http = require('http')
var parseUrl = require('parseurl')
var send = require('send')

var app = http.createServer(function onRequest (req, res) {
  // your custom error-handling logic:
  function error (err) {
    res.statusCode = err.status || 500
    res.end(err.message)
  }

  // your custom headers
  function headers (res, path, stat) {
    // serve all files for download
    res.setHeader('Content-Disposition', 'attachment')
  }

  // your custom directory handling logic:
  function redirect () {
    res.statusCode = 301
    res.setHeader('Location', req.url + '/')
    res.end('Redirecting to ' + req.url + '/')
  }

  // transfer arbitrary files from within
  // /www/example.com/public/*
  send(req, parseUrl(req).pathname, {root: '/www/example.com/public'})
  .on('error', error)
  .on('directory', redirect)
  .on('headers', headers)
  .pipe(res);
}).listen(3000)
```

## License 

[MIT](LICENSE)

[npm-image]: https://img.shields.io/npm/v/send.svg
[npm-url]: https://npmjs.org/package/send
[travis-image]: https://img.shields.io/travis/pillarjs/send/master.svg?label=linux
[travis-url]: https://travis-ci.org/pillarjs/send
[appveyor-image]: https://img.shields.io/appveyor/ci/dougwilson/send/master.svg?label=windows
[appveyor-url]: https://ci.appveyor.com/project/dougwilson/send
[coveralls-image]: https://img.shields.io/coveralls/pillarjs/send/master.svg
[coveralls-url]: https://coveralls.io/r/pillarjs/send?branch=master
[downloads-image]: https://img.shields.io/npm/dm/send.svg
[downloads-url]: https://npmjs.org/package/send
[gratipay-image]: https://img.shields.io/gratipay/dougwilson.svg
[gratipay-url]: https://www.gratipay.com/dougwilson/