AutoCAD Slide

import magic
# Libmagic will reliably detect the 'AutoCAD Slide' header string
print(magic.from_file('blueprint.sld', mime=True)) # May output 'image/vnd.sld' or 'application/octet-stream' depending on the definition file

const fs = require('fs');
// Manually detecting the AutoCAD Slide magic string
const buffer = Buffer.alloc(13);
const fd = fs.openSync('blueprint.sld', 'r');
fs.readSync(fd, buffer, 0, 13, 0);
fs.closeSync(fd);
const isSLD = buffer.toString('ascii') === 'AutoCAD Slide';
console.log('Is AutoCAD Slide:', isSLD);

import (
    "bytes"
    "net/http"
)
// http.DetectContentType will not natively recognize this format. Use a custom prefix check:
// isSLD := bytes.HasPrefix(buf, []byte("AutoCAD Slide"))

$mime = mime_content_type('blueprint.sld');
echo $mime; // Standard PHP installations often fall back to 'application/octet-stream'