function main(){
    while(ture){
        var pos = exchange.GetPosition()
        var ticker = exchange.GetTicekr()
        if(!ticker){return '无法获取ticker'}
        if(!pos || pos.length == 0 ){return '已无持仓'}
        for(var i=0;i<pos.length;i++){
            if(pos[i].Type == PD_LONG){
                exchange.SetContractType(pos[i].ContractType)
                exchange.SetDirection('closebuy')
                exchange.Sell(ticker.Buy, pos[i].Amount - pos[i].FrozenAmount)