Iterating through all players in raid for buff

[labmixz]

I'm sure this has been answered 1000x over, but trying to search on [these] forums, with the keywords I've been using hasn't brought me any results.

I'm looking to iterate over all the players in a raid, scanning for a buff. Without getting it to be too complex. Just wondering what the best method for doing this is? Lets say I want to look for Shadowcore Oil [spell id: 320798].


One tutorial I've found, has something like below. However, I can't see how this would iterate through all players in the raid. This seems more like it's iterating through the buffs on the player, which I need to do as well, just need to expand it to also include every other play (in raid).

local buffFound = 0
for i=1,40 do
    local name, icon, _, _, _, etime = UnitBuff("player",i)
    if name == "Shadowcore Oil" then
        buffFound = buffFound + 1
    end
end

Thanks in advance!

Edit: Of course I put this in the wrong forum :'( If someone could move it, that would be great.