第3章 HDFS：分布式文件系统
3.5 HDFS基本命令
HDFS命令官方文档：
http://hadoop.apache.org/docs/r2.7.3/hadoop-project-dist/hadoop-hdfs/HDFSCommands.html
3.5.1 用法
[root@node1 ~]# hdfs dfs
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] <localsrc> ... <dst>]
[-copyToLocal [-p] [-ignoreCrc] [-crc] <src> ... <localdst>]
[-count [-q] [-h] [-v] [-x] <path> ...]
[-cp [-f] [-p | -p[topax]] <src> ... <dst>]
[-createSnapshot <snapshotDir> [<snapshotName>]]
[-deleteSnapshot <snapshotDir> <snapshotName>]
[-df [-h] [<path> ...]]
[-du [-s] [-h] [-x] <path> ...]
[-expunge]
[-find <path> ... <expression> ...]
[-get [-p] [-ignoreCrc] [-crc] <src> ... <localdst>]
[-getfacl [-R] <path>]
[-getfattr [-R] {-n name | -d} [-e en] <path>]
[-getmerge [-nl] <src> <localdst>]
[-help [cmd ...]]
[-ls [-C] [-d] [-h] [-q] [-R] [-t] [-S] [-r] [-u] [<path> ...]]
[-mkdir [-p] <path> ...]
[-moveFromLocal <localsrc> ... <dst>]
[-moveToLocal <src> <localdst>]
[-mv <src> ... <dst>]
[-put [-f] [-p] [-l] <localsrc> ... <dst>]
[-renameSnapshot <snapshotDir> <oldName> <newName>]
[-rm [-f] [-r|-R] [-skipTrash] <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] <file>]
[-test -[defsz] <path>]
[-text [-ignoreCrc] <src> ...]
[-touchz <path> ...]
[-usage [cmd ...]]
Generic options supported are
-conf <configuration file> specify an application configuration file
-D <property=value> use value for given property
-fs <local|namenode:port> specify a namenode
-jt <local|resourcemanager:port> specify a ResourceManager
-files <comma separated list of files> specify comma separated files to be copied to the map reduce cluster
-libjars <comma separated list of jars> specify comma separated jar files to include in the classpath.
-archives <comma separated list of archives> specify comma separated archives to be unarchived on the compute machines.
The general command line syntax is
bin/hadoop command [genericOptions] [commandOptions]3.5.2 hdfs dfs -mkdir
The -p option behavior is much like Unix mkdir -p, creating parent directories along the path.
[root@node1 ~]# hdfs dfs -mkdir -p input
[root@node1 ~]# hdfs dfs -mkdir -p /abchdfs创建的目录默认会放到/user/{username}/目录下面，其中{username}是当前用户名。所以input目录应该在/user/root/下面。
在HDFS根目录下创建abc目录。
3.5.3 hdfs dfs -ls
[root@node1 ~]# hdfs dfs -ls /
Found 2 items
drwxr-xr-x - root supergroup 0 2017-05-14 09:40 /abc
drwxr-xr-x - root supergroup 0 2017-05-14 09:37 /user
[root@node1 ~]# hdfs dfs -ls /user
Found 1 items
drwxr-xr-x - root supergroup 0 2017-05-14 09:37 /user/root
[root@node1 ~]# hdfs dfs -ls /user/root
Found 1 items
drwxr-xr-x - root supergroup 0 2017-05-14 09:37 /user/root/input3.5.4 hdfs dfs -put
Usage: hdfs dfs -put …
Copy single src, or multiple srcs from local file system to the destination file system. Also reads input from stdin and writes to destination file system.
hdfs dfs -put localfile /user/hadoop/hadoopfile
hdfs dfs -put localfile1 localfile2 /user/hadoop/hadoopdir
hdfs dfs -put localfile hdfs://nn.example.com/hadoop/hadoopfile
hdfs dfs -put - hdfs://nn.example.com/hadoop/hadoopfile Reads the input from stdin.
Exit Code:
Returns 0 on success and -1 on error.