{"success":true,"data":{"ext":"opt","name":"Developer Studio File Workspace Options subheader","description":"Developer Studio File Workspace Options subheader (OPT) is a legacy Microsoft file format used within Microsoft Developer Studio to store workspace configuration data. It supports development environments by preserving project settings, user preferences, and build options so the IDE can restore a developer’s workspace across sessions. The format is generally considered safe, though it is associated with older Visual Studio-era tooling and is rarely encountered outside legacy projects and archived development files.","mime":[],"risk_level":"Safe","signatures":[{"hex":"D0 CF 11 E0 A1 B1 1A E1","offset":0,"sources":[{"name":"Gary Kessler","url":"https://www.garykessler.net/library/file_sigs_GCK_latest.html"}]},{"hex":"FD FF FF FF 20 00 00 00","offset":512,"sources":[{"name":"Gary Kessler","url":"https://www.garykessler.net/library/file_sigs_GCK_latest.html"}]}],"related":["sou"],"usage":{"python":"def is_opt(file_path: str) -> bool:\n    \"\"\"Check if file is a valid OPT by magic bytes.\"\"\"\n    signature = bytes([0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1])\n    with open(file_path, \"rb\") as f:\n        return f.read(8) == signature","node":"function isOPT(buffer: Buffer): boolean {\n  const signature = Buffer.from([0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1]);\n  return buffer.subarray(0, 8).equals(signature);\n}","go":"func IsOPT(data []byte) bool {\n    signature := []byte{0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1}\n    if len(data) < 8 {\n        return false\n    }\n    return bytes.Equal(data[:8], signature)\n}"}}}