{"success":true,"data":{"ext":"wk1","name":"Lotus 1-2-3 spreadsheet","description":"Lotus 1-2-3 spreadsheet (WK1) is a legacy spreadsheet file format developed by Lotus Development Corporation for use in the Lotus 1-2-3 application. It is used to store worksheets, formulas, and basic business data, and was common in early DOS-based office workflows and compatible spreadsheet programs. The format is obsolete but generally safe to open, though older files may not preserve all features when imported into modern software.","mime":["application/vnd.lotus-1-2-3;version=2"],"risk_level":"Safe","signatures":[{"hex":"00 00 02 00 06 04 06 00 08 00 00 00 00 00","offset":0,"sources":[{"name":"Wikipedia","url":"https://en.wikipedia.org/wiki/List_of_file_signatures"},{"name":"Gary Kessler","url":"https://www.garykessler.net/library/file_sigs_GCK_latest.html"}]},{"hex":"00 00 02 00 06 04 06 00 08 00","offset":0,"sources":[{"name":"Apache Tika","url":"https://raw.githubusercontent.com/apache/tika/main/tika-core/src/main/resources/org/apache/tika/mime/tika-mimetypes.xml"}]}],"related":["wk3","wk4","apr","lwp","nsf","123"],"usage":{"python":"def is_wk1(file_path: str) -> bool:\n    \"\"\"Check if file is a valid WK1 by magic bytes.\"\"\"\n    signature = bytes([0x00, 0x00, 0x02, 0x00, 0x06, 0x04, 0x06, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00])\n    with open(file_path, \"rb\") as f:\n        return f.read(14) == signature","node":"function isWK1(buffer: Buffer): boolean {\n  const signature = Buffer.from([0x00, 0x00, 0x02, 0x00, 0x06, 0x04, 0x06, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00]);\n  return buffer.subarray(0, 14).equals(signature);\n}","go":"func IsWK1(data []byte) bool {\n    signature := []byte{0x00, 0x00, 0x02, 0x00, 0x06, 0x04, 0x06, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00}\n    if len(data) < 14 {\n        return false\n    }\n    return bytes.Equal(data[:14], signature)\n}"},"category":"Office"}}