hadoop(五): shell命令

hdfs dfs

  • -cat URI : 查看文件内容
    1. hdfs dfs -cat hdfs dfs -cat hdfs://mycluster/user/root/rcc1
    2. hdfs dfs -cat file:///usr/hdp/2.4.2.0-258/hadoop/bin/rcc
  • -ls <args>: 查文件列表
    1. 返回格式:permissions number_of_replicas userid groupid filesize modification_date modification_time filename
      [root@hdp2 ~]# hdfs dfs -ls Found 4 items drwx------ - root hdfs 0 2016-09-01 21:00 .Trash drwxr-xr-x - root hdfs 0 2016-08-12 12:29 .hiveJars -rw-r--r-- 3 root hdfs        531 2016-09-01 12:53 mapred -rw-r--r-- 3 root hdfs       1857 2016-09-01 12:44 rcc1
  • -mkdir <paths>   : 创建目录
    1. The behavior is much like unix mkdir -p creating parent directories along the path
      [root@hdp2 ~]# hdfs dfs -ls Found 4 items drwx------ - root hdfs 0 2016-09-01 21:00 .Trash drwxr-xr-x - root hdfs 0 2016-08-12 12:29 .hiveJars -rw-r--r-- 3 root hdfs        531 2016-09-01 12:53 mapred -rw-r--r-- 3 root hdfs       1857 2016-09-01 12:44 rcc1 [root@hdp2 ~]# hdfs dfs -mkdir hdfs://mycluster/user/root/zhu
      [root@hdp2 ~]# hdfs dfs -ls Found 5 items drwx------ - root hdfs 0 2016-09-01 21:00 .Trash drwxr-xr-x - root hdfs 0 2016-08-12 12:29 .hiveJars -rw-r--r-- 3 root hdfs        531 2016-09-01 12:53 mapred -rw-r--r-- 3 root hdfs       1857 2016-09-01 12:44 rcc1 drwxr-xr-x - root hdfs 0 2016-09-02 04:35 zhu
  • -copyFromLocal <localsrc> URI: 上传文件,类似于put
  • -put <localsrc> … <dst>
[root@hdp2 ~]# hdfs dfs -ls /user/root/zhu [root@hdp2 ~]# hdfs dfs -put /usr/zhu/a1.png /user/root/zhu [root@hdp2 ~]# hdfs dfs -copyFormLocal /usr/zhu/a2.png /user/root/zhu -copyFormLocal: Unknown command [root@hdp2 ~]# hdfs dfs -copyFromLocal /usr/zhu/a2.png /user/root/zhu [root@hdp2 ~]# hdfs dfs -ls /user/root/zhu Found 2 items -rw-r--r-- 3 root hdfs      86908 2016-09-02 04:48 /user/root/zhu/a1.png -rw-r--r-- 3 root hdfs      55823 2016-09-02 04:49 /user/root/zhu/a2.png [root@hdp2 ~]#

 

  • -copyToLocal [-ignorecrc] [-crc] URI <localdst> : 下载到本地
  • -get [-ignorecrc] [-crc] <src> <localdst>
    [root@hdp2 ~]# clear [root@hdp2 ~]# hdfs dfs -ls /user/root/zhu Found 2 items -rw-r--r-- 3 root hdfs      86908 2016-09-02 04:48 /user/root/zhu/a1.png -rw-r--r-- 3 root hdfs      55823 2016-09-02 04:49 /user/root/zhu/a2.png [root@hdp2 ~]# hdfs dfs -copyToLocal hdfs://mycluster/user/root/zhu/a1.png /usr/zhu/tmp
    [root@hdp2 ~]# hdfs dfs -get /usr/root/zhu/a2.png /usr/zhu/tmp get: `/usr/root/zhu/a2.png': No such file or directory
    [root@hdp2 ~]# hdfs dfs -get /user/root/zhu/a2.png /usr/zhu/tmp [root@hdp2 ~]# cd /usr/zhu/tmp [root@hdp2 tmp]# ll total 144 -rw-r--r-- 1 root root 86908 Sep  2 04:54 a1.png -rw-r--r-- 1 root root 55823 Sep  2 04:55 a2.png [root@hdp2 tmp]# 
    1.  

  • -count [-q] <paths> :统计
    1. The output columns with -count are: DIR_COUNT, FILE_COUNT, CONTENT_SIZE FILE_NAME
    2. The output columns with -q are: QUOTA, REMAINING_QUATA, SPACE_QUOTA, REMAINING_SPACE_QUOTA
      [root@hdp2 tmp]# hdfs dfs -count /user/root/zhu 1            2             142731 /user/root/zhu [root@hdp2 tmp]# hdfs dfs -count -q /user/root/zhu none inf none inf 1            2             142731 /user/root/zhu [root@hdp2 tmp]# 
    3.  

  • -du [-s] [-h] URI [URI …]:  统计大小
    1. The -s option will result in an aggregate summary of file lengths being displayed, rather than the individual file
    2. The -h option will format file sizes in a “human-readable” fashion (e.g 64.0m instead of 67108864)
      [root@hdp2 tmp]# hdfs dfs -du -h /user/root/zhu 84.9 K /user/root/zhu/a1.png 54.5 K /user/root/zhu/a2.png [root@hdp2 tmp]# 
  • -rm -r [-skipTrash] URI [URI …]
    1. -r: Recursive version of delete
      [root@hdp2 tmp]# hdfs dfs -ls /user/root/zhu Found 1 items -rw-r--r-- 3 root hdfs      86908 2016-09-02 05:03 /user/root/zhu/a1.png [root@hdp2 tmp]# hdfs dfs -rm -r /user/root/zhu 16/09/02 05:04:29 INFO fs.TrashPolicyDefault: Namenode trash configuration: Deletion interval = 360 minutes, Emptier interval = 0 minutes. Moved: 'hdfs://mycluster/user/root/zhu' to trash at: hdfs://mycluster/user/root/.Trash/Current
      [root@hdp2 tmp]# hdfs dfs -ls /user/root/zhu ls: `/user/root/zhu': No such file or directory
      [root@hdp2 tmp]# 
  • -touchz URI [URI …]
    1. Create a file of zero length
      [root@hdp2 tmp]# hdfs dfs -ls Found 4 items drwx------ - root hdfs 0 2016-09-02 05:02 .Trash drwxr-xr-x - root hdfs 0 2016-08-12 12:29 .hiveJars -rw-r--r-- 3 root hdfs        531 2016-09-01 12:53 mapred -rw-r--r-- 3 root hdfs       1857 2016-09-01 12:44 rcc1 [root@hdp2 tmp]# hdfs dfs -touchz a.txt [root@hdp2 tmp]# hdfs dfs -ls Found 5 items drwx------ - root hdfs 0 2016-09-02 05:02 .Trash drwxr-xr-x - root hdfs 0 2016-08-12 12:29 .hiveJars -rw-r--r-- 3 root hdfs          0 2016-09-02 05:08 a.txt -rw-r--r-- 3 root hdfs        531 2016-09-01 12:53 mapred -rw-r--r-- 3 root hdfs       1857 2016-09-01 12:44 rcc1 [root@hdp2 tmp]# hdfs dfs -cat /user/root/a.txt [root@hdp2 tmp]# 
  • 小结:
  •  本质就是linux文件操作命令
    原文作者:DFS
    原文地址: https://www.cnblogs.com/tgzhu/p/5830845.html
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