Crate mimetype_detector 

mimetype-detector

A comprehensive Rust library for detecting MIME types and file extensions based on magic numbers. This library provides fast, accurate, and thread-safe MIME type detection for ~450 file formats across all major categories.

Features

• Fast and precise MIME type detection using magic number analysis
• 527 supported formats including images, audio, video, documents, archives, and more
• Thread-safe operations with lazy initialization
• Zero unsafe code - built with RwLock and LazyLock for safety
• Memory efficient - reads only first 3KB of files
• Zero dependencies - pure Rust implementation

Quick Start

use mimetype_detector::{detect, detect_file};

// Detect from byte data
let data = b"\x89PNG\r\n\x1a\n";
let mime_type = detect(data);
println!("MIME type: {}", mime_type); // image/png
println!("Name: {}", mime_type.name()); // Portable Network Graphics
println!("Extension: {}", mime_type.extension()); // .png
assert!(!mime_type.name().is_empty());
println!("Kind: {}", mime_type.kind()); // IMAGE

// Detect from file
let mime_type = detect_file("test.png")?;
println!("File type: {}", mime_type);

Architecture

The library uses a hierarchical tree structure for MIME type detection:

• Tree-based detection: Organizes formats by priority and relationships
• Private matchers: Detection algorithms are encapsulated and not exposed
• Lazy initialization: MIME type tree is built on first use
• Static lifetime: All MIME type data lives for the entire program duration

Supported Formats

• Images: PNG, JPEG, GIF, WebP, TIFF, BMP, SVG, DDS, PCX, KTX, ASTC, and 20+ others
• Audio: MP3, FLAC, WAV, OGG, AAC, WavPack, TTA, DSF, DFF, and 15+ others
• Video: MP4, WebM, AVI, MKV, MPEG, and 8+ others
• Documents: PDF, HTML, XML, Office formats, and more
• Archives: ZIP, TAR, 7Z, RAR, GZIP, LZ4, and 15+ others
• Executables: ELF, PE/EXE, Mach-O, Java CLASS, WASM
• Fonts: TTF, OTF, WOFF, WOFF2, EOT, TTC
• 3D/CAD: Blender (.blend), PLY, GLB, GLTF, DWG, DXF
• Network/Debug: PCAP, PCAPNG for packet capture analysis
• And many more: See documentation for complete list

Custom Matchers

You can register custom detection functions for additional MIME types:

use mimetype_detector::{register_mime, match_mime};

// Register a custom matcher
register_mime("application/x-custom", |data| {
    data.starts_with(b"CUSTOM")
});

// Test the custom matcher
let data = b"CUSTOM file content";
assert!(match_mime(data, "application/x-custom"));

Re-exports

pub use mime_type::MimeType;

pub use kind::MimeKind;

pub use constants::*;

Modules

constants

Public constants for all supported MIME types.

kind

MIME type categorization using bitflags

mime_type

Functions

detect

Detects the MIME type of the given byte data.

detect_file

Detects the MIME type of a file at the given path.

detect_file_with_limit

Detects the MIME type of a file at the given path with a custom read limit.

detect_reader

Detects the MIME type by reading from a Read implementor.

detect_reader_with_limit

Detects the MIME type by reading from a Read implementor with a custom read limit.

detect_with_limit

Detects the MIME type of the given byte data with a custom read limit.

equals_any

Checks if a MIME type equals any of the provided types.

is_supported

Checks if a MIME type is supported by the library.

is_supported_extension

Checks if a file extension is supported by the library.

match_extension

Checks if the given data matches a specific file extension.

match_file

Checks if a file matches a specific MIME type.

match_file_extension

Checks if a file matches a specific file extension.

match_mime

Checks if the given data matches a specific MIME type.

match_reader

Checks if data from a reader matches a specific MIME type.

match_reader_extension

Checks if data from a reader matches a specific file extension.

register_extension

Registers a custom matcher function for a specific file extension.

register_mime

Registers a custom matcher function for a specific MIME type.