{"success":true,"data":{"ext":"au","name":"NeXT/Sun Microsystems µ-Law audio file","description":"NeXT/Sun Microsystems µ-Law audio file is an audio file format developed by NeXT and later supported by Sun Microsystems for storing mu-law encoded sound data. It is used for simple audio playback, archival voice recordings, and legacy Unix audio workflows, especially on older systems and software. The format is largely legacy and poses no special security concerns beyond the usual risks associated with opening untrusted media files.","mime":["audio/basic"],"risk_level":"Safe","signatures":[{"hex":"2E 73 6E 64","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"},{"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":"2E 73 6E 64 00 00 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"}]},{"hex":"64 6E 73 2E","offset":0,"sources":[{"name":"Gary Kessler","url":"https://www.garykessler.net/library/file_sigs_GCK_latest.html"}]}],"related":["snd","aac","ac3","aif","aifc","aiff"],"usage":{"python":"def is_au(file_path: str) -> bool:\n    \"\"\"Check if file is a valid AU by magic bytes.\"\"\"\n    signature = bytes([0x2E, 0x73, 0x6E, 0x64])\n    with open(file_path, \"rb\") as f:\n        return f.read(4) == signature","node":"function isAU(buffer: Buffer): boolean {\n  const signature = Buffer.from([0x2E, 0x73, 0x6E, 0x64]);\n  return buffer.subarray(0, 4).equals(signature);\n}","go":"func IsAU(data []byte) bool {\n    signature := []byte{0x2E, 0x73, 0x6E, 0x64}\n    if len(data) < 4 {\n        return false\n    }\n    return bytes.Equal(data[:4], signature)\n}"},"category":"Audio"}}