MimeTypeCore – All the MIME/file extension pairs you will ever need

4 months ago 17

Fast MIME type mapping library for the .NET ecosystem. Supports almost any Core and Framework version, including netstandard1.2, net40, and net8.0. Extensively tested, focused on performance, and working out of the box. Get your MIME type or extension and be done with it fast. The mapping is zero-config by default and sourced from authoritative sources, such as IANA, and MimeType. About 2,000 extensions and MIME types are mapped. MimeTypeCore builds upon MimeTypeMap.

Install the package:

dotnet add package MimeTypeCore

Get MIME type from an extension, or vice versa:

using MimeTypeCore; MimeTypeMap.TryGetMimeType(".png", out string mimeTypePng); // image/png MimeTypeMap.TryGetExtension("image/png", out string extension); // .png

⭐ That's it! Please consider starring this repository if you find it helpful.

Sometimes, one extension can have multiple MIME types associated. For example, .ts might be text/typescript, or video/mpeg (ts stands for Transport Stream in this case). To resolve the collision, provide Stream to the file, so the header can be sampled for a known sequence of magic bytes:

using FileStream streamVideo = File.Open("files/video.ts", FileMode.Open); using FileStream streamTypescript = File.Open("files/typescript.ts", FileMode.Open); MimeTypeMap.TryGetMimeType(streamVideo, out string mimeTypeVideo); // video/mpeg MimeTypeMap.TryGetMimeType(streamTypescript, out string mimeTypeTypescript); // text/typescript

When dealing with user-provided files, whether from Blazor or MVC, your input is likely to be IBrowserFile or IFormFile. These streams don't support synchronous reading, use MimeTypeMap.TryGetMimeTypeAsync:

IBrowserFile file; // for example from InputFileChangeEventArgs try { // 500 MB, use reasonable limits out there await using Stream stream = file.OpenReadStream(512_000_000); // null if not recognized, your MIME type otherwise string? mimeType = await MimeTypeMap.TryGetMimeTypeAsync(args.File.Name, stream); } catch (Exception e) // the file size is probably over the OpenReadStream limit { }

To contribute, check the mapping file for the hardcoded mappings, and add new entries. Please follow the code style and alphabetical ordering. Magic headers can be contributed to this file. If you are touching anything beyond that, provide relevant test cases. Thank you.

This library is licensed under the MIT license. 💜

Read Entire Article

MimeTypeCore – All the MIME/file extension pairs you will ever need

Related

GitSocial

LLMs can hide text in other text of the same length

You Don't Own Your Reputation