Tagged Image File Format (Legacy MIME)

import magic
# Modern Libmagic will output the standardized 'image/tiff' rather than the legacy 'x-tiff'
print(magic.from_file('scan.tiff', mime=True)) # Outputs 'image/tiff'

const mime = require('mime');
// JS libraries resolve .tiff strictly to the IANA standard image/tiff
console.log(mime.getType('scan.tiff')); // Outputs 'image/tiff'

// Manually detecting the TIFF magic bytes
const fs = require('fs');
const buffer = Buffer.alloc(4);
const fd = fs.openSync('scan.tiff', 'r');
fs.readSync(fd, buffer, 0, 4, 0);
fs.closeSync(fd);
const isLittleEndian = buffer[0] === 0x49 && buffer[1] === 0x49 && buffer[2] === 0x2A && buffer[3] === 0x00;
const isBigEndian = buffer[0] === 0x4D && buffer[1] === 0x4D && buffer[2] === 0x00 && buffer[3] === 0x2A;
console.log('Is TIFF:', isLittleEndian || isBigEndian);

import (
    "bytes"
    "net/http"
)
// Native Go HTTP detection reads the 'II*' or 'MM*' header
// mime := http.DetectContentType(buf) // Returns "image/tiff"

// Example of normalizing the legacy MIME type during a file upload in PHP
$mime = $_FILES['upload']['type'];
if ($mime === 'image/x-tiff') {
    $mime = 'image/tiff';
}
echo $mime;