简介

本文主要介绍hdfs通过命令行操作文件

操作文件有几种方式，看个人习惯

hdfs dfs 
hdfs fs
hadoop fs

个人习惯使用 hadoop fs 可操作任何对象，命令基本上跟linux命令一样

Usage

[hadoop@hadoop01 ~]$ hadoop fs
Usage: hadoop fs [generic options]
	[-appendToFile <localsrc> ... <dst>]
	[-cat [-ignoreCrc] <src> ...]
	[-checksum <src> ...]
	[-chgrp [-R] GROUP PATH...]
	[-chmod [-R] <MODE[,MODE]... | OCTALMODE> PATH...]
	[-chown [-R] [OWNER][:[GROUP]] PATH...]
	[-copyFromLocal [-f] [-p] [-l] [-d] [-t <thread count>] [-q <thread pool queue size>] <localsrc> ... <dst>]
	[-copyToLocal [-f] [-p] [-crc] [-ignoreCrc] [-t <thread count>] [-q <thread pool queue size>] <src> ... <localdst>]
	[-count [-q] [-h] [-v] [-t [<storage type>]] [-u] [-x] [-e] <path> ...]
	[-cp [-f] [-p | -p[topax]] [-d] [-t <thread count>] [-q <thread pool queue size>] <src> ... <dst>]
	[-createSnapshot <snapshotDir> [<snapshotName>]]
	[-deleteSnapshot <snapshotDir> <snapshotName>]
	[-df [-h] [<path> ...]]
	[-du [-s] [-h] [-v] [-x] <path> ...]
	[-expunge [-immediate]]
	[-find <path> ... <expression> ...]
	[-get [-f] [-p] [-crc] [-ignoreCrc] [-t <thread count>] [-q <thread pool queue size>] <src> ... <localdst>]
	[-getfacl [-R] <path>]
	[-getfattr [-R] {-n name | -d} [-e en] <path>]
	[-getmerge [-nl] [-skip-empty-file] <src> <localdst>]
	[-head <file>]
	[-help [cmd ...]]
	[-ls [-C] [-d] [-h] [-q] [-R] [-t] [-S] [-r] [-u] [-e] [<path> ...]]
	[-mkdir [-p] <path> ...]
	[-moveFromLocal [-f] [-p] [-l] [-d] <localsrc> ... <dst>]
	[-moveToLocal <src> <localdst>]
	[-mv <src> ... <dst>]
	[-put [-f] [-p] [-l] [-d] [-t <thread count>] [-q <thread pool queue size>] <localsrc> ... <dst>]
	[-renameSnapshot <snapshotDir> <oldName> <newName>]
	[-rm [-f] [-r|-R] [-skipTrash] [-safely] <src> ...]
	[-rmdir [--ignore-fail-on-non-empty] <dir> ...]
	[-setfacl [-R] [{-b|-k} {-m|-x <acl_spec>} <path>]|[--set <acl_spec> <path>]]
	[-setfattr {-n name [-v value] | -x name} <path>]
	[-setrep [-R] [-w] <rep> <path> ...]
	[-stat [format] <path> ...]
	[-tail [-f] [-s <sleep interval>] <file>]
	[-test -[defswrz] <path>]
	[-text [-ignoreCrc] <src> ...]
	[-touch [-a] [-m] [-t TIMESTAMP (yyyyMMdd:HHmmss) ] [-c] <path> ...]
	[-touchz <path> ...]
	[-truncate [-w] <length> <path> ...]
	[-usage [cmd ...]]

Generic options supported are:
-conf <configuration file>        specify an application configuration file
-D <property=value>               define a value for a given property
-fs <file:///|hdfs://namenode:port> specify default filesystem URL to use, overrides 'fs.defaultFS' property from configurations.
-jt <local|resourcemanager:port>  specify a ResourceManager
-files <file1,...>                specify a comma-separated list of files to be copied to the map reduce cluster
-libjars <jar1,...>               specify a comma-separated list of jar files to be included in the classpath
-archives <archive1,...>          specify a comma-separated list of archives to be unarchived on the compute machines

The general command line syntax is:
command [genericOptions] [commandOptions]

创建文件夹

hadoop fs -mkdir -p /shura/test

-p 递归创建目录

创建文件

hadoop fs -touch /shura/1.txt

删除文件

[hadoop@hadoop01 ~]$ hadoop fs -rm -f -r /shura/1.txt
Deleted /shura/1.txt

上传文件

相当于 cp

hadoop fs –put [-f] [-p] <src> <dst>
-f          覆盖目标文件
-p          保留访问和修改时间、所有权和权限
localsrc    本地的文件
dst         hdfs的目录

hadoop fs -put hadoop-3.2.4.tar.gz /shura

查看目录内容

hadoop fs -ls /shura

-h 比较人性化的显示文件大小

-R 递归查找

[hadoop@hadoop01 ~]$ hadoop fs -ls /shura
Found 2 items
-rw-r--r-- 2 hadoop supergroup 492368219 2023-11-17 16:38 /shura/hadoop-3.2.4.tar.gz
drwxr-xr-x - hadoop supergroup 0 2023-11-17 16:35 /shura/test

[hadoop@hadoop01 ~]$ hadoop fs -ls -h /shura
Found 2 items
-rw-r--r--   2 hadoop supergroup    469.6 M 2023-11-17 16:38 /shura/hadoop-3.2.4.tar.gz
drwxr-xr-x   - hadoop supergroup          0 2023-11-17 16:35 /shura/test

上传并删除原文件

相当于 mv

hadoop fs –moveFromLocal src dest

查看文件内容

echo -e '123\n456' > test.txt
hadoop fs -put test.txt /shura/test
[hadoop@hadoop01 ~]$ hadoop fs -cat /shura/test/test.txt
1123
111

## 查看文件前1kb内容
[hadoop@hadoop01 ~]$ hadoop fs -head /shura/test/test.txt
1123
111

## 查看文件后1kb内容
[hadoop@hadoop01 ~]$ hadoop fs -tail /shura/test/test.txt
1123
111

下载文件

hadoop fs –get [-f] [-p] hdfs文件 本地文件
-f   覆盖目标文件
-p   保留文件信息

## 合并下载的文件
hadoop fs –getmerge [-nl] [-skip-empty-file] hdfs文件 本地文件
-nl   每个文件末尾添加换行符
-skip-empty-file   跳过空白文件

## 例如
hadoop fs –getmerge -nl -skip-empty-file /shura/test/* merge.txt

拷贝文件

hadoop fs –cp [-f] <src> <dest>
-f   覆盖目标文件

追加数据到文件

hadoop fs –appendToFile <src> <dest>
src  本地文件,
dest 目标文件不存在则创建

注意如果src为 “-”,那么数据将从标准输入读取

例如

[hadoop@hadoop01 ~]$ hadoop fs -appendToFile - /shura/test/test.txt
hello
shura
^C[hadoop@hadoop01 ~]$

[hadoop@hadoop01 ~]$ hadoop fs -tail  /shura/test/test.txt
1123
111
hello
shura

查看磁盘空间

[hadoop@hadoop01 ~]$ hadoop fs -df -h /
Filesystem       Size     Used  Available  Use%
hdfs://shura  294.5 G  946.7 M    252.9 G    0%

目录使用空间

[hadoop@hadoop01 ~]$ hadoop fs -du -s -h /shura
469.6 M  939.1 M  /shura

checksum校验码

[hadoop@hadoop01 ~]$ hadoop fs -checksum /shura/hadoop-3.2.4.tar.gz
/shura/hadoop-3.2.4.tar.gz	MD5-of-262144MD5-of-512CRC32C	000002000000000000040000cd85610e03aa708a87471aac4801e9da

修改文件所属 chown

hadoop fs -chown hadoop:hadoop /shura/hadoop-3.2.4.tar.gz

查找

[hadoop@hadoop01 ~]$ hadoop fs -find /shura test*
/shura
/shura/hadoop-3.2.4.tar.gz
/shura/test
/shura/test/test.txt

修改文件副本数

hadoop fs –setrep [-R] [-w] <rep> <path>

-R 递归
-w 客户端是否等待副本修改完毕


[hadoop@hadoop01 ~]$ hadoop fs -setrep -R -w 3 /shura/test/test.txt
Replication 3 set: /shura/test/test.txt
Waiting for /shura/test/test.txt .... done

总结

hdfs对文件常用的操作大致就是这些，后面我们开始yarn的部署

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