* From 1.0.0 until 1.1.1, `md5` is a function to compute an MD5 hash ([Read about it here.](https://github.com/richardgirges/express-fileupload/releases/tag/v1.0.0-alpha.1)).
safeFileNames | <ul><li><code>false</code> **(default)**</li><li><code>true</code></li><li>regex</li></ul> | Strips characters from the upload's filename. You can use custom regex to determine what to strip. If set to `true`, non-alphanumeric characters _except_ dashes and underscores will be stripped. This option is off by default.<br/><br/>**Example #1 (strip slashes from file names):** `app.use(fileUpload({ safeFileNames: /\\/g }))`<br/>**Example #2:** `app.use(fileUpload({ safeFileNames: true }))`
preserveExtension | <ul><li><code>false</code> **(default)**</li><li><code>true</code></li><li><code>*Number*</code></li></ul> | Preserves filename extension when using <code>safeFileNames</code> option. If set to <code>true</code>, will default to an extension length of 3. If set to <code>*Number*</code>, this will be the max allowable extension length. If an extension is smaller than the extension length, it remains untouched. If the extension is longer, it is shifted.<br/><br/>**Example #1 (true):**<br/><code>app.use(fileUpload({ safeFileNames: true, preserveExtension: true }));</code><br/>*myFileName.ext* --> *myFileName.ext*<br/><br/>**Example #2 (max extension length 2, extension shifted):**<br/><code>app.use(fileUpload({ safeFileNames: true, preserveExtension: 2 }));</code><br/>*myFileName.ext* --> *myFileNamee.xt*
abortOnLimit | <ul><li><code>false</code> **(default)**</li><li><code>true</code></ul> | Returns a HTTP 413 when the file is bigger than the size limit if true. Otherwise, it will add a <code>truncated = true</code> to the resulting file structure.
responseOnLimit | <ul><li><code>'File size limit has been reached'</code> **(default)**</li><li><code>*String*</code></ul> | Response which will be send to client if file size limit exceeded when abortOnLimit set to true.
limitHandler | <ul><li><code>false</code> **(default)**</li><li><code>function(req, res, next)</code></li></ul> | User defined limit handler which will be invoked if the file is bigger than configured limits.
useTempFiles | <ul><li><code>false</code> **(default)**</li><li><code>true</code></ul> | By default this module uploads files into RAM. Setting this option to True turns on using temporary files instead of utilising RAM. This avoids memory overflow issues when uploading large files or in case of uploading lots of files at same time.
tempFileDir | <ul><li><code>String</code> **(path)**</li></ul> | Path to store temporary files.<br/>Used along with the <code>useTempFiles</code> option. By default this module uses 'tmp' folder in the current working directory.<br/>You can use trailing slash, but it is not necessary.
parseNested | <ul><li><code>false</code> **(default)**</li><li><code>true</code></li></ul> | By default, req.body and req.files are flattened like this: <code>{'name': 'John', 'hobbies[0]': 'Cinema', 'hobbies[1]': 'Bike'}</code><br/><br/>When this option is enabled they are parsed in order to be nested like this: <code>{'name': 'John', 'hobbies': ['Cinema', 'Bike']}</code>
debug | <ul><li><code>false</code> **(default)**</li><li><code>true</code></ul> | Turn on/off upload process logging. Can be useful for troubleshooting.
uploadTimeout | <ul><li><code>60000</code> **(default)**</li><li><code>Integer</code></ul> | This defines how long to wait for data before aborting. Set to 0 if you want to turn off timeout checks.
[Brian White](https://github.com/mscdex) for his stellar work on the [Busboy Package](https://github.com/mscdex/busboy) and the [connect-busboy Package](https://github.com/mscdex/connect-busboy)