Portable Anymap

import magic
# Libmagic will typically resolve PNM files specifically to their sub-format (e.g., 'image/x-portable-pixmap' for P3/P6)
print(magic.from_file('image.pnm', mime=True))

const fs = require('fs');
// Manually checking the PNM magic bytes (P1 through P6)
const buffer = Buffer.alloc(2);
const fd = fs.openSync('image.pnm', 'r');
fs.readSync(fd, buffer, 0, 2, 0);
fs.closeSync(fd);
const isPNM = buffer[0] === 0x50 && buffer[1] >= 0x31 && buffer[1] <= 0x36;
console.log('Is Portable Anymap (PNM):', isPNM);

import (
    "bytes"
    "net/http"
)
// Native Go HTTP detection might not map specifically to the 'anymap' umbrella.
// Check directly for the P1-P6 signatures:
// isPNM := len(buf) >= 2 && buf[0] == 'P' && buf[1] >= '1' && buf[1] <= '6'

$mime = mime_content_type('image.pnm');
echo $mime; // Standard PHP setups will likely return the specific sub-type like 'image/x-portable-pixmap'