Hadoop学习笔记（五）---HDFS shell操作

1.查看hadoop上根目录的文件：

[root@localhost current]# hadoop fs -ls /

2.上传文件到hadoop：

[root@localhost hadoop]# vim aaa
[root@localhost hadoop]# hadoop fs -put aaa /
Warning: $HADOOP_HOME is deprecated.

[root@localhost hadoop]# hadoop fs -ls /
Warning: $HADOOP_HOME is deprecated.

Found 2 items
-rw-r--r--   1 root supergroup         11 2015-05-31 07:18 /aaa
drwxr-xr-x   - root supergroup          0 2015-05-31 03:19 /usr

我先创建了一个文件aaa，然后用命令hadoop fs -put aaa /，指的是把aaa这个文件上传到hadoop的根目录，然后我又查看了以下文件，发现hadoop下面有了我上传的文件

3.查看文件内容 hadoop fs -cat /aaa

[root@localhost hadoop]# hadoop fs -cat /aaa
Warning: $HADOOP_HOME is deprecated.

helloworld

4.改变权限 hadoop fs -chmod 777 /aaa

[root@localhost hadoop]# hadoop fs -chmod 777 /aaa
Warning: $HADOOP_HOME is deprecated.

[root@localhost hadoop]# hadoop fs -ls /
Warning: $HADOOP_HOME is deprecated.

Found 2 items
-rw-rw-rw-   1 root supergroup         11 2015-05-31 07:18 /aaa
drwxr-xr-x   - root supergroup          0 2015-05-31 03:19 /usr

hadoop是没有执行权限的，所以你即便是给文件可读，可写，可执行，hadoop也不会给他可执行权限

5.复制远程的内容到本地：

[root@localhost hadoop]# hadoop fs -get /aaa ./bbb
Warning: $HADOOP_HOME is deprecated.

[root@localhost hadoop]# ls
aaa  bbb  Desktop  Documents  Downloads  Music  Pictures  Public  Templates  Videos

这里说的是把hadoop根目录下面的aaa文件复制到本地当前目录下面的bbb文件，完成后你会发现多了一个bbb文件

6.统计远程的文件 ：

[root@localhost hadoop]# hadoop fs -count /
Warning: $HADOOP_HOME is deprecated.

           7            2                 15 hdfs://172.21.15.189:9000/

这里指的是hadoop根目录下面有7个文件夹，2个文件，占15个字节

7.hadoop复制文件：

[root@localhost hadoop]# hadoop fs -cp /aaa /bbb
Warning: $HADOOP_HOME is deprecated.

[root@localhost hadoop]# hadoop fs -ls /
Warning: $HADOOP_HOME is deprecated.

Found 3 items
-rw-rw-rw-   1 root supergroup         11 2015-05-31 07:18 /aaa
-rw-r--r--   1 root supergroup         11 2015-05-31 07:34 /bbb
drwxr-xr-x   - root supergroup          0 2015-05-31 03:19 /usr

你会发现根目录下面多了一个bbb文件

8.递归列出文件：

[root@localhost hadoop]# hadoop fs -lsr /
Warning: $HADOOP_HOME is deprecated.

-rw-rw-rw-   1 root supergroup         11 2015-05-31 07:18 /aaa
-rw-r--r--   1 root supergroup         11 2015-05-31 07:34 /bbb
drwxr-xr-x   - root supergroup          0 2015-05-31 03:19 /usr
drwxr-xr-x   - root supergroup          0 2015-05-31 03:19 /usr/local
drwxr-xr-x   - root supergroup          0 2015-05-31 03:19 /usr/local/hadoop
drwxr-xr-x   - root supergroup          0 2015-05-31 03:19 /usr/local/hadoop/tmp
drwxr-xr-x   - root supergroup          0 2015-05-31 03:19 /usr/local/hadoop/tmp/mapred
drwx------   - root supergroup          0 2015-05-31 03:36 /usr/local/hadoop/tmp/mapred/system
-rw-------   1 root supergroup          4 2015-05-31 03:36 /usr/local/hadoop/tmp/mapred/system/jobtracker.info

你会发现所有的文件都递归列出来了

9.创建文件夹

[root@localhost hadoop]# hadoop fs -mkdir /mydir
Warning: $HADOOP_HOME is deprecated.

[root@localhost hadoop]# hadoop fs -ls /
Warning: $HADOOP_HOME is deprecated.

Found 4 items
-rw-rw-rw-   1 root supergroup         11 2015-05-31 07:18 /aaa
-rw-r--r--   1 root supergroup         11 2015-05-31 07:34 /bbb
drwxr-xr-x   - root supergroup          0 2015-05-31 07:43 /mydir
drwxr-xr-x   - root supergroup          0 2015-05-31 03:19 /usr

10.移动或者重命名文件：

[root@localhost hadoop]# hadoop fs -mv /aaa /helloworld
Warning: $HADOOP_HOME is deprecated.

[root@localhost hadoop]# hadoop fs -ls /
Warning: $HADOOP_HOME is deprecated.

Found 4 items
-rw-r--r--   1 root supergroup         11 2015-05-31 07:34 /bbb
-rw-rw-rw-   1 root supergroup         11 2015-05-31 07:18 /helloworld
drwxr-xr-x   - root supergroup          0 2015-05-31 07:43 /mydir
drwxr-xr-x   - root supergroup          0 2015-05-31 03:19 /usr

11.删除文件或者文件夹：

文件：

[root@localhost hadoop]# hadoop fs -rm /bbb
Warning: $HADOOP_HOME is deprecated.

Deleted hdfs://172.21.15.189:9000/bbb
[root@localhost hadoop]# hadoop fs -ls /
Warning: $HADOOP_HOME is deprecated.

Found 3 items
-rw-rw-rw-   1 root supergroup         11 2015-05-31 07:18 /helloworld
drwxr-xr-x   - root supergroup          0 2015-05-31 07:43 /mydir
drwxr-xr-x   - root supergroup          0 2015-05-31 03:19 /usr

文件夹：

[root@localhost hadoop]# hadoop fs -rmr /mydir
Warning: $HADOOP_HOME is deprecated.

Deleted hdfs://172.21.15.189:9000/mydir
[root@localhost hadoop]# hadoop fs -ls /
Warning: $HADOOP_HOME is deprecated.

Found 2 items
-rw-rw-rw-   1 root supergroup         11 2015-05-31 07:18 /helloworld
drwxr-xr-x   - root supergroup          0 2015-05-31 03:19 /usr

12.创建文件：

[root@localhost hadoop]# hadoop fs -touchz /aaa
Warning: $HADOOP_HOME is deprecated.

[root@localhost hadoop]# hadoop fs -ls /
Warning: $HADOOP_HOME is deprecated.

Found 3 items
-rw-r--r--   1 root supergroup          0 2015-05-31 07:55 /aaa
-rw-rw-rw-   1 root supergroup         11 2015-05-31 07:18 /helloworld
drwxr-xr-x   - root supergroup          0 2015-05-31 03:19 /usr