p = peripheral.wrap("back")

function isPlayerOnline(playerName)
  local data = p.getPlayers()
  local playerCounter = 0
  local playerList = {}

  for i,j in pairs(data) do
    playerCounter = playerCounter + 1
    playerList[i] = j["name"]
    print(j["name"])
  end

  for i,j in pairs(playerList) do
    if j == playerName then
      return true
    else
      return false
    end
  end
end

print(isPlayerOnline("awade_"))