hadoop常用命令实例

1、查看指定目录下内容：hadoop fs –ls [文件目录]
[root@cdh01 tmp]# hadoop fs -ls -h /tmp
Found 2 items
drwxrwxrwx - hdfs supergroup 0 2016-01-21 10:24 /tmp/.cloudera_health_monitoring_canary_files
drwx-wx-wx - hive supergroup 0 2016-01-21 10:02 /tmp/hive
[root@cdh01 tmp]# hadoop fs -ls -h /
Found 2 items
drwxrwxrwx - hdfs supergroup 0 2016-01-21 10:02 /tmp
drwxrwxr-x - hdfs supergroup 0 2016-01-21 10:01 /user

2、将本地文件夹存储至hadoop上：hadoop fs –put [本地目录] [hadoop目录]
[root@cdh01 /]# mkdir test_put_dir #创建目录
[root@cdh01 /]# chown hdfs:hadoop test_put_dir #赋目录权限给hadoop用户
[root@cdh01 /]# su hdfs #切换到hadoop用户
[hdfs@cdh01 /]$ls bin boot dev dfs dfs_bak etc home lib lib64 lost+found media misc mnt net opt proc root sbin selinux srv sys test_put_dir tmp usr var wawa.txt wbwb.txt wyp.txt [hdfs@cdh01 /]$ hadoop fs -put test_put_dir /
[hdfs@cdh01 /]$ hadoop fs -ls /
Found 4 items
drwxr-xr-x - hdfs supergroup 0 2016-01-21 11:07 /hff
drwxr-xr-x - hdfs supergroup 0 2016-01-21 15:25 /test_put_dir
drwxrwxrwt - hdfs supergroup 0 2016-01-21 10:39 /tmp
drwxr-xr-x - hdfs supergroup 0 2016-01-21 10:39 /user

3、在hadoop指定目录内创建新目录：hadoop fs –mkdir [目录地址]
[root@cdh01 /]# su hdfs
[hdfs@cdh01 /]$ hadoop fs -mkdir /hff

4、在hadoop指定目录下新建一个空文件，使用touchz命令：
[hdfs@cdh01 /]$hadoop fs -touchz /test_put_dir/test_new_file.txt [hdfs@cdh01 /]$ hadoop fs -ls /test_put_dir
Found 1 items
-rw-r–r– 3 hdfs supergroup 0 2016-01-21 15:29 /test_put_dir/test_new_file.txt

5、将本地文件存储至hadoop上：hadoop fs –put [本地地址] [hadoop目录]
[hdfs@cdh01 /]$hadoop fs -put wyp.txt /hff #直接目录 [hdfs@cdh01 /]$ hadoop fs -put wyp.txt hdfs://cdh01.cap.com:8020/hff #服务器目录
注：文件wyp.txt放在/根目录下，结构如：
bin dfs_bak lib64 mnt root sys var
boot etc lost+found net sbin test_put_dir wawa2.txt
dev home media opt selinux tmp wbwb.txt
dfs lib misc proc srv usr wyp.txt

6、打开某个已存在文件：hadoop fs –cat [file_path]
[hdfs@cdh01 /]$ hadoop fs -cat /hff/wawa.txt
1 张三 男 135
2 刘丽 女 235
3 王五 男 335

7、将hadoop上某个文件重命名hadoop fs –mv [旧文件名] [新文件名]
[hdfs@cdh01 /]$ hadoop fs -mv /tmp /tmp_bak #修改文件夹名

8、将hadoop上某个文件down至本地已有目录下：hadoop fs -get [文件目录] [本地目录]
[hdfs@cdh01 /]$hadoop fs -get /hff/wawa.txt /test_put_dir [hdfs@cdh01 /]$ ls -l /test_put_dir/
total 4
-rw-r–r– 1 hdfs hdfs 42 Jan 21 15:39 wawa.txt

9、删除hadoop上指定文件：hadoop fs -rm [文件地址]
[hdfs@cdh01 /]$hadoop fs -ls /test_put_dir/ Found 2 items -rw-r–r– 3 hdfs supergroup 0 2016-01-21 15:41 /test_put_dir/new2.txt -rw-r–r– 3 hdfs supergroup 0 2016-01-21 15:29 /test_put_dir/test_new_file.txt [hdfs@cdh01 /]$ hadoop fs -rm /test_put_dir/new2.txt
16/01/21 15:42:24 INFO fs.TrashPolicyDefault: Namenode trash configuration: Deletion interval = 1440 minutes, Emptier interval = 0 minutes.
Moved: ‘hdfs://cdh01.cap.com:8020/test_put_dir/new2.txt’ to trash at: hdfs://cdh01.cap.com:8020/user/hdfs/.Trash/Current
[hdfs@cdh01 /]$ hadoop fs -ls /test_put_dir/
Found 1 items
-rw-r–r– 3 hdfs supergroup 0 2016-01-21 15:29 /test_put_dir/test_new_file.txt

10、删除hadoop上指定文件夹（包含子目录等）：hadoop fs –rm -r [目录地址]
[hdfs@cdh01 /]$hadoop fs -rmr /test_put_dir 16/01/21 15:50:59 INFO fs.TrashPolicyDefault: Namenode trash configuration: Deletion interval = 1440 minutes, Emptier interval = 0 minutes. Moved: ‘hdfs://cdh01.cap.com:8020/test_put_dir’ to trash at: hdfs://cdh01.cap.com:8020/user/hdfs/.Trash/Current [hdfs@cdh01 /]$ hadoop fs -ls /
Found 3 items
drwxr-xr-x - hdfs supergroup 0 2016-01-21 11:07 /hff
drwxrwxrwt - hdfs supergroup 0 2016-01-21 10:39 /tmp
drwxr-xr-x - hdfs supergroup 0 2016-01-21 15:42 /user

11、将hadoop指定目录下所有内容保存为一个文件，同时down至本地
hadoop dfs –getmerge /user /home/t

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12、将正在运行的hadoop作业kill掉
hadoop job –kill [job-id]