^{Using my app is also a way to support me:}

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FileType

This tool detects a file’s MIME type using magic bytes and can retrieve the file extension based on the MIME type.
It can identify the MIME type of Data, based on Swime and ported from file-type.

The Extensions, mimeTypes, and mimeTypesAll data in the dependency package are all generated by scripts based on file-type.

The function for checking whether the bytes match the MimeType specification is generated from a mapping.js mapping file created using data from the file-type package.
Since the data may not always be accurate, it can be corrected by modifying the mapping.js file.

Installation

Swift Package Manager

Add CodeMirror to your project using Xcode:

1. In Xcode, go to File → Add Package Dependencies...
2. Enter the repository URL: https://github.com/jaywcjlove/FileType.git
3. Click Add Package

Or add it to your Package.swift file:

dependencies: [
    .package(url: "https://github.com/jaywcjlove/FileType.git", from: "1.0.0")
]

Usage

Inspect mime type

import FileType

let path = "/path/to/some-file.jpg"
let url = URL(fileURLWithPath: path, isDirectory: false)
let data = try! Data(contentsOf: url)
let mimeType = FileType.mimeType(data: data)

mimeType?.type == .jpg // true
mimeType! // MimeType(mime: "image/jpeg", ext: "jpg", type: .jpg)

Get the file extension from a MIME type

let avroMimeType = MimeType.mimeTypesAll.first { $0.mime == "application/avro" }
if let avroMimeType = avroMimeType {
    avroMimeType.mime   // "application/avro"
    avroMimeType.type   // .avro
    avroMimeType.type.rawValue // "avro"
}

let mimeTypes = MimeType.mimeTypes.first(where: { $0.key == "application/mp4" })
if let mimeTypes = mimeTypes {
    mimeTypes.compressible
    mimeTypes.extensions // ["mp4","mpg4","mp4s","m4p"]
}

Acknowledgments

Thanks to these projects:

• https://github.com/sendyhalim/Swime
• https://github.com/sindresorhus/file-type
• https://github.com/jshttp/mime-db

License

Licensed under the MIT License.