### 调用ECS DescribeInstances接口（默认单页）

Source: https://help.aliyun.com/zh/cli/aggregation-of-paging-interface-results

执行此命令仅返回实例信息列表的第一页数据。适用于需要单页数据或不关心全量数据的场景。

```bash
aliyun ecs DescribeInstances
```

--------------------------------

### ECS DescribeInstances接口默认单页查询结果示例

Source: https://help.aliyun.com/zh/cli/aggregation-of-paging-interface-results

展示了调用 `aliyun ecs DescribeInstances` 命令后返回的单页查询结果的JSON格式。注意其中分页相关的字段。

```json
{
    "PageNumber": 1,
    "TotalCount": 4,
    "PageSize": 10,
    "RequestId": "6EA82E70-9750-4A97-A738-E021D8A57F07",
    "Instances": {
        "Instance": [
            {
                "InstanceId": "i-m5edv0cqkr9hawls****",
                "ImageId": "win2012r2_64_dtc_9600_zh-cn_40G_alibase_20190318.vhd",
                "SerialNumber": "f06857e8-7f3c-443a-9f88-8e84eb51****",
                "Cpu": 1,
                "Memory": 2048,
                "DeviceAvailable": true,
                "SecurityGroupIds": {
                    "SecurityGroupId": [
                        "sg-bp1fgviwol82z8ap****"
                    ]
                }
            }
        ]
    }
}
```

--------------------------------

### 聚合分页类接口查询结果（指定参数）

Source: https://help.aliyun.com/zh/cli/aggregation-of-paging-interface-results

使用 `--pager` 选项并显式指定分页相关字段，可一次性获取所有分页中的实例信息。适用于需要全量数据的场景。

```bash
aliyun ecs DescribeInstances --pager PageNumber=PageNumber PageSize=PageSize TotalCount=TotalCount path=Instances.Instance
```