{"success":true,"data":{"ext":"wk4","name":"Lotus 1-2-3 spreadsheet","description":"Lotus 1-2-3 spreadsheet (WK4) is a legacy spreadsheet file format created by Lotus Development Corporation for the Lotus 1-2-3 application, later supported by IBM after its acquisition of Lotus. It was used for business spreadsheets, calculations, and tabular data exchange in desktop productivity suites such as Lotus 1-2-3 and compatible office software. The format is obsolete and, like other legacy spreadsheets, should be opened with trusted software when handling older files.","mime":["application/vnd.lotus-1-2-3;version=4"],"risk_level":"Safe","signatures":[{"hex":"00 00 1A 00 02 10 04 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 1A 00 02 10 04 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","123","wk1","apr","lwp","nsf"],"usage":{"python":"def is_wk4(file_path: str) -> bool:\n    \"\"\"Check if file is a valid WK4 by magic bytes.\"\"\"\n    signature = bytes([0x00, 0x00, 0x1A, 0x00, 0x02, 0x10, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00])\n    with open(file_path, \"rb\") as f:\n        return f.read(12) == signature","node":"function isWK4(buffer: Buffer): boolean {\n  const signature = Buffer.from([0x00, 0x00, 0x1A, 0x00, 0x02, 0x10, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00]);\n  return buffer.subarray(0, 12).equals(signature);\n}","go":"func IsWK4(data []byte) bool {\n    signature := []byte{0x00, 0x00, 0x1A, 0x00, 0x02, 0x10, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00}\n    if len(data) < 12 {\n        return false\n    }\n    return bytes.Equal(data[:12], signature)\n}"},"category":"Office"}}