# hadoop fs / hdfs

## hadoop 指令用起來就像 Linux 指令一般，但他以 `Hadoop fs`作為指令，而以 Linux 指令作為 args。

## 常見的如下：

> * **顯示目錄下所有檔案 :**
>
> > ### **`hadoop fs -ls <hdfs file path>`**
>
> * **取得檔案內容 :**
>
> > ### **`hadoop fs -cat <hdfs file path>`**
>
> * **取得 尾部1000 字節內的檔案內容(同 unix 系統的 tail)：**
>
> > ### **`hadoop fs -tail <hdfs file path>`**
>
> * **搬動檔案 :**
>
> > ### **`hadoop fs -mv <hdfs file path>`**
>
> * **複製檔案 :**
>
> > ### **`hadoop fs -cp <hdfs file path from> <hdfs file path destination>`**
>
> * **建立路徑 :**
>
> > ### **`hadoop fs -mkdir <hdfs file path>`**
>
> * **確認檔案狀態 -e:檔案是否存在, -z: 檔案是否為空,  -d: 是否是目錄 :**
>
> > ### **`hadoop fs -test [-ezd]`**
>
> * **將本地檔案置放到 hdfs 上**
>
> > ### **`hadoop fs -put <local file> <hdfs file path>`**
>
> * **刪除檔案**
>
> > ### **`hadoop -rm [-r] <hdfs file path>`**

### 以上範例使用 hadoop fs ，但在新版本裡頭，這已經處於 deplicate 的狀態，後續建議用 hdfs dfs 的指令。


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