Mime

.NET wrapper for libmagic

Install

PM> Install-Package Mime

Requirements

Supported runtimes:

linux-musl-x64
linux-x64
osx-arm64(tested on macOS 13 Ventura)
osx-x64
win-x64

Basic usage

using HeyRed.Mime;

// (Optionally) You can set path to magic database file manually.
MimeGuesser.MagicFilePath = "/path/to/magic.mgc";

// Guess mime type of file(overloaded method takes byte array or stream as arg.)
MimeGuesser.GuessMimeType("path/to/file"); //=> image/jpeg

// Get extension of file(overloaded method takes byte array or stream as arg.)
MimeGuesser.GuessExtension("path/to/file"); //=> jpeg

// Get mime type and extension of file(overloaded method takes byte array or stream as arg.)
MimeGuesser.GuessFileType("path/to/file"); //=> FileType

Advanced

Want more than just the mime type? Use the Magic class:

string calc = @"C:\Windows\System32\calc.exe";
using var magic = new Magic(MagicOpenFlags.MAGIC_NONE);
magic.Read(calc); //=> PE32+ executable (GUI) x86-64, for MS Windows

// Check encoding:
string textFile = @"F:\Temp\file.txt";
using var magic = new Magic(MagicOpenFlags.MAGIC_MIME_ENCODING);
magic.Read(textFile); //=> Output: utf-8

Also, we can combine flags with "|" operator. See all flags for more info.

Remarks

The Magic class is not thread safe, but if you use different instances on different threads it seems to work fine.
The MimeGuesser is thread safe, since it generates a new instance of Magic class on each use.

Possible problems

Exception	Solution
DllNotFoundException	Make sure that your `bin` folder contains runtimes directory. If you publishing platform dependent app, then `bin` should be contains `libmagic-1`(.dll, .so or .dylib) and `magic.mgc` files.
BadImageFormatException	Make sure when you target the `AnyCPU` platform the `Prefer 32-bit` option is unchecked. Or try to target `x64/arm64` instead.
MagicException: Could not find any valid magic files!	Make sure your magic.mgc file contains in one of /runtimes/ subdirs or along with libmagic-1.[dll\|lib\|dylib]. Or set path to custom database as described in basic usage