{"success":true,"data":{"ext":"chi","name":"Microsoft Compiled HTML Help File","description":"Microsoft Compiled HTML Help is a proprietary help file format developed and maintained by Microsoft for Windows-based documentation systems. It stores compressed HTML pages, images, and navigation data for application help manuals, reference materials, and software assistance. The format is now largely legacy, and compiled help files have historically been associated with security concerns because they may contain active content, so files from untrusted sources should be opened cautiously.","mime":[],"risk_level":"Safe","signatures":[{"hex":"49 54 53 46","offset":0,"sources":[{"name":"Gary Kessler","url":"https://www.garykessler.net/library/file_sigs_GCK_latest.html"}]}],"related":["chm"],"usage":{"python":"def is_chi(file_path: str) -> bool:\n    \"\"\"Check if file is a valid CHI by magic bytes.\"\"\"\n    signature = bytes([0x49, 0x54, 0x53, 0x46])\n    with open(file_path, \"rb\") as f:\n        return f.read(4) == signature","node":"function isCHI(buffer: Buffer): boolean {\n  const signature = Buffer.from([0x49, 0x54, 0x53, 0x46]);\n  return buffer.subarray(0, 4).equals(signature);\n}","go":"func IsCHI(data []byte) bool {\n    signature := []byte{0x49, 0x54, 0x53, 0x46}\n    if len(data) < 4 {\n        return false\n    }\n    return bytes.Equal(data[:4], signature)\n}"}}}