parse non-linear binary file format

[blissful valve]

std.fs.File has seek* and getPos

it also has seekableStream

[unborn lion]

as for the readUN() methods, the are available throught file.reader()

const file = try std.fs.cwd().openFile("path", .{});
defer file.close();
const reader = file.reader();
const magic = try reader.readIntLittle(u16);

this is just a std.io.Reader(...)