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Hadoop之hdfs操作

HDFS的常见Shell操作

直接在命令行中输入hdfs dfs,可以查看dfs后面可以跟的所有参数
注意:这里面的[]表示是可选项,<>表示是必填项

  1. [root@bigdata01 hadoop-3.3.2]# hdfs dfs
  2. Usage: hadoop fs [generic options]
  3. [-appendToFile <localsrc> ... <dst>]
  4. [-cat [-ignoreCrc] <src> ...]
  5. [-checksum [-v] <src> ...]
  6. [-chgrp [-R] GROUP PATH...]
  7. [-chmod [-R] <MODE[,MODE]... | OCTALMODE> PATH...]
  8. [-chown [-R] [OWNER][:[GROUP]] PATH...]
  9. [-concat <target path> <src path> <src path> ...]
  10. [-copyFromLocal [-f] [-p] [-l] [-d] [-t <thread count>] [-q <thread pool queue size>] <localsrc> ... <dst>]
  11. [-copyToLocal [-f] [-p] [-crc] [-ignoreCrc] [-t <thread count>] [-q <thread pool queue size>] <src> ... <localdst>]
  12. [-count [-q] [-h] [-v] [-t [<storage type>]] [-u] [-x] [-e] [-s] <path> ...]
  13. [-cp [-f] [-p | -p[topax]] [-d] [-t <thread count>] [-q <thread pool queue size>] <src> ... <dst>]
  14. [-createSnapshot <snapshotDir> [<snapshotName>]]
  15. [-deleteSnapshot <snapshotDir> <snapshotName>]
  16. [-df [-h] [<path> ...]]
  17. [-du [-s] [-h] [-v] [-x] <path> ...]
  18. [-expunge [-immediate] [-fs <path>]]
  19. [-find <path> ... <expression> ...]
  20. [-get [-f] [-p] [-crc] [-ignoreCrc] [-t <thread count>] [-q <thread pool queue size>] <src> ... <localdst>]
  21. [-getfacl [-R] <path>]
  22. [-getfattr [-R] {-n name | -d} [-e en] <path>]
  23. [-getmerge [-nl] [-skip-empty-file] <src> <localdst>]
  24. [-head <file>]
  25. [-help [cmd ...]]
  26. [-ls [-C] [-d] [-h] [-q] [-R] [-t] [-S] [-r] [-u] [-e] [<path> ...]]
  27. [-mkdir [-p] <path> ...]
  28. [-moveFromLocal [-f] [-p] [-l] [-d] <localsrc> ... <dst>]
  29. [-moveToLocal <src> <localdst>]
  30. [-mv <src> ... <dst>]
  31. [-put [-f] [-p] [-l] [-d] [-t <thread count>] [-q <thread pool queue size>] <localsrc> ... <dst>]
  32. [-renameSnapshot <snapshotDir> <oldName> <newName>]
  33. [-rm [-f] [-r|-R] [-skipTrash] [-safely] <src> ...]
  34. [-rmdir [--ignore-fail-on-non-empty] <dir> ...]
  35. [-setfacl [-R] [{-b|-k} {-m|-x <acl_spec>} <path>]|[--set <acl_spec> <path>]]
  36. [-setfattr {-n name [-v value] | -x name} <path>]
  37. [-setrep [-R] [-w] <rep> <path> ...]
  38. [-stat [format] <path> ...]
  39. [-tail [-f] [-s <sleep interval>] <file>]
  40. [-test -[defswrz] <path>]
  41. [-text [-ignoreCrc] <src> ...]
  42. [-touch [-a] [-m] [-t TIMESTAMP (yyyyMMdd:HHmmss) ] [-c] <path> ...]
  43. [-touchz <path> ...]
  44. [-truncate [-w] <length> <path> ...]
  45. [-usage [cmd ...]]
  46. >Generic options supported are:
  47. -conf <configuration file> specify an application configuration file
  48. -D <property=value> define a value for a given property
  49. -fs <file:///|hdfs://namenode:port> specify default filesystem URL to use, overrides 'fs.defaultFS' property from configurations.
  50. -jt <local|resourcemanager:port> specify a ResourceManager
  51. -files <file1,...> specify a comma-separated list of files to be copied to the map reduce cluster
  52. -libjars <jar1,...> specify a comma-separated list of jar files to be included in the classpath
  53. -archives <archive1,...> specify a comma-separated list of archives to be unarchived on the compute machines
  54. >
  55. >The general command line syntax is:
  56. command [genericOptions] [commandOptions]

-ls:查询指定路径信息

查看hdfs根目录下的内容,默认情况下hdfs中什么都没有

  1. [root@bigdata01 hadoop-3.3.2]# hdfs dfs -ls hdfs://bigdata01:9000/
  2. Found 23 items
  3. -rw-r--r-- 2 root supergroup 15217 2022-04-04 16:19 hdfs://bigdata01:9000/LICENSE.txt
  4. -rw-r--r-- 3 30329 supergroup 482 2022-04-19 16:47 hdfs://bigdata01:9000/MapFile
  5. -rw-r--r-- 2 root supergroup 1541 2022-04-04 16:19 hdfs://bigdata01:9000/NOTICE.txt
  6. -rw-r--r-- 3 30329 supergroup 482 2022-04-19 16:50 hdfs://bigdata01:9000/SeqFile
  7. -rw-r--r-- 2 root supergroup 1860100000 2022-04-20 13:14 hdfs://bigdata01:9000/hello_10000000.dat
  8. drwxr-xr-x - root supergroup 0 2022-04-10 12:14 hdfs://bigdata01:9000/log
  9. drwxr-xr-x - 30329 supergroup 0 2022-04-19 16:50 hdfs://bigdata01:9000/mapFile
  10. drwxr-xr-x - root supergroup 0 2022-04-12 17:37 hdfs://bigdata01:9000/out
  11. drwxr-xr-x - root supergroup 0 2022-04-12 17:51 hdfs://bigdata01:9000/out1
  12. drwxr-xr-x - root supergroup 0 2022-04-19 17:18 hdfs://bigdata01:9000/out10
  13. drwxr-xr-x - root supergroup 0 2022-04-20 16:32 hdfs://bigdata01:9000/out10000000
  14. drwxr-xr-x - root supergroup 0 2022-04-19 17:28 hdfs://bigdata01:9000/out11
  15. drwxr-xr-x - root supergroup 0 2022-04-19 17:30 hdfs://bigdata01:9000/out12
  16. drwxr-xr-x - root supergroup 0 2022-04-12 18:05 hdfs://bigdata01:9000/out2
  17. drwxr-xr-x - root supergroup 0 2022-04-13 19:31 hdfs://bigdata01:9000/out4
  18. drwxr-xr-x - root supergroup 0 2022-04-13 19:51 hdfs://bigdata01:9000/out5
  19. drwxr-xr-x - root supergroup 0 2022-04-13 20:03 hdfs://bigdata01:9000/out6
  20. drwxr-xr-x - root supergroup 0 2022-04-28 21:25 hdfs://bigdata01:9000/outqueue
  21. -rw-r--r-- 2 root supergroup 161 2022-04-29 08:23 hdfs://bigdata01:9000/relation.dat
  22. drwxr-xr-x - root supergroup 0 2022-04-12 17:30 hdfs://bigdata01:9000/test
  23. drwx------ - root supergroup 0 2022-04-13 19:51 hdfs://bigdata01:9000/tmp
  24. drwx------ - root supergroup 0 2022-04-10 11:04 hdfs://bigdata01:9000/user
  25. -rw-r--r-- 3 30329 supergroup 13 2022-04-05 20:58 hdfs://bigdata01:9000/user1.txt

其实后面hdfs的url这一串内容在使用时默认是可以省略的,因为hdfs在执行的时候会根据HDOOP_HOME自动识别配置文件中的fs.defaultFS属性
所以这样简写也是可以的

  1. [root@bigdata01 hadoop-3.3.2]# hdfs dfs -ls /
  2. Found 23 items
  3. -rw-r--r-- 2 root supergroup 15217 2022-04-04 16:19 /LICENSE.txt
  4. -rw-r--r-- 3 30329 supergroup 482 2022-04-19 16:47 /MapFile
  5. -rw-r--r-- 2 root supergroup 1541 2022-04-04 16:19 /NOTICE.txt
  6. -rw-r--r-- 3 30329 supergroup 482 2022-04-19 16:50 /SeqFile
  7. -rw-r--r-- 2 root supergroup 1860100000 2022-04-20 13:14 /hello_10000000.dat
  8. drwxr-xr-x - root supergroup 0 2022-04-10 12:14 /log
  9. drwxr-xr-x - 30329 supergroup 0 2022-04-19 16:50 /mapFile
  10. drwxr-xr-x - root supergroup 0 2022-04-12 17:37 /out
  11. drwxr-xr-x - root supergroup 0 2022-04-12 17:51 /out1
  12. drwxr-xr-x - root supergroup 0 2022-04-19 17:18 /out10
  13. drwxr-xr-x - root supergroup 0 2022-04-20 16:32 /out10000000
  14. drwxr-xr-x - root supergroup 0 2022-04-19 17:28 /out11
  15. drwxr-xr-x - root supergroup 0 2022-04-19 17:30 /out12
  16. drwxr-xr-x - root supergroup 0 2022-04-12 18:05 /out2
  17. drwxr-xr-x - root supergroup 0 2022-04-13 19:31 /out4
  18. drwxr-xr-x - root supergroup 0 2022-04-13 19:51 /out5
  19. drwxr-xr-x - root supergroup 0 2022-04-13 20:03 /out6
  20. drwxr-xr-x - root supergroup 0 2022-04-28 21:25 /outqueue
  21. -rw-r--r-- 2 root supergroup 161 2022-04-29 08:23 /relation.dat
  22. drwxr-xr-x - root supergroup 0 2022-04-12 17:30 /test
  23. drwx------ - root supergroup 0 2022-04-13 19:51 /tmp
  24. drwx------ - root supergroup 0 2022-04-10 11:04 /user
  25. -rw-r--r-- 3 30329 supergroup 13 2022-04-05 20:58 /user1.txt

-put: 从本地上传文件

接下来我们向hdfs中上传一个文件,使用Hadoop中的README.txt,直接上传到hdfs的根目录即可

  1. [root@bigdata01 hadoop-3.3.2]# hdfs dfs -put README.txt /

上传成功之后没有任何提示,注意,没有提示就是最好的结果
确认一下刚才上传的文件

  1. [root@bigdata01 hadoop-3.3.2]# hdfs dfs -ls /

在这里可以发现使用hdfs中的ls查询出来的信息和在linux中执行ll查询出来的信息是类似的
在这里能看到这个文件就说明刚才的上传操作是成功的

-cat: 查看HDFS文件内容

文件上传上去以后,查看一下HDFS中文件的内容,使用cat即可

  1. [root@bigdata01 hadoop-3.3.2]# hdfs dfs -cat /README.txt

-get: 下载文件到本地

如果我们想把hdfs中的文件下载到本地linux文件系统中需要怎么做呢?使用get即可实现

  1. [root@bigdata01 hadoop-3.3.2]# hdfs dfs -get /README.txt

-mkdir[-p]: 创建文件夹

后期我们需要在hdfs中维护很多文件,所以就需要创建文件夹来进行分类管理了
下面我们来创建一个文件夹,hdfs中使用mkdir命令

  1. [root@bigdata01 hadoop-3.3.2]# hdfs dfs -mkdir /test

如果要递归创建多级目录,还需要再指定-p参数

  1. [root@bigdata01 hadoop-3.3.2]# hdfs dfs -mkdir -o /abc/xyz

想要递归显示所有目录的信息,可以在ls后面添加-R参数

  1. [root@bigdata01 hadoop-3.3.2]# hdfs dfs -ls -R /

-rm[-r]: 删除文件/文件夹

如果想要删除hdfs中的目录或者文件,可以使用rm
删除文件

  1. [root@bigdata01 hadoop-3.3.2]# hdfs dfs -rm /README.txt

删除目录,注意,删除目录需要指定-r参数

  1. [root@bigdata01 hadoop-3.3.2]# hdfs dfs -rm -r /abc
标签: hadoop hdfs big data

本文转载自: https://blog.csdn.net/qq_52150032/article/details/124786520
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