sniff static method
Implementation
static UDocKind sniff(Uint8List head) {
if (head.length >= 5 && head[0] == 0x25 && head[1] == 0x50 && head[2] == 0x44 && head[3] == 0x46 && head[4] == 0x2D) return UDocKind.pdf;
if (head.length >= 4 && head[0] == 0x50 && head[1] == 0x4B && (head[2] == 0x03 || head[2] == 0x05 || head[2] == 0x07)) return UDocKind.epub;
for (int i = 0; i + 4 < head.length && i < 1024; i++) {
if (head[i] == 0x25 && head[i + 1] == 0x50 && head[i + 2] == 0x44 && head[i + 3] == 0x46) return UDocKind.pdf;
}
return UDocKind.unknown;
}