Learning Hadoop Commands

FS Commands
http://hadoop.apache.org/docs/r2.2.0/hadoop-project-dist/hadoop-common/FileSystemShell.html

appendToFile
hdfs dfs -appendToFile localfile hdfs://nn.example.com/hadoop/hadoopfile
hdfs dfs -appendToFile - hdfs://nn.example.com/hadoop/hadoopfile Reads the input from stdin.

hdfs dfs -cat hdfs://nn1.example.com/file1 hdfs://nn2.example.com/file2
hdfs dfs -chgrp [-R] GROUP URI [URI ...]
hdfs dfs -chmod [-R] <MODE[,MODE]... | OCTALMODE> URI [URI ...]
hdfs dfs -chown [-R] [OWNER][:[GROUP]] URI [URI ]
hdfs dfs -copyFromLocal <localsrc> URI
hdfs dfs -copyToLocal [-ignorecrc] [-crc] URI <localdst>
hdfs dfs -count [-q] <paths>
hdfs dfs -cp [-f] URI [URI ...] <dest>

hdfs dfs -du [-s] [-h] URI [URI ...]
Displays sizes of files and directories contained in the given directory or the length of a file in case its just a file.
The -s option will result in an aggregate summary of file lengths being displayed, rather than the individual files.
The -h option will format file sizes in a "human-readable" fashion (e.g 64.0m instead of 67108864)

hdfs dfs -expunge
Empty the Trash.

hdfs dfs -dus <args>
Displays a summary of file lengths. This is an alternate form of hdfs dfs -du -s.

hdfs dfs -get [-ignorecrc] [-crc] <src> <localdst>
Copy files to the local file system.
hdfs dfs -get hdfs://nn.example.com/user/hadoop/file localfile

hdfs dfs -ls <args>
hdfs dfs -mkdir [-p] <paths>
hdfs dfs -rm [-skipTrash] URI [URI ...]
Delete files specified as args. Only deletes non empty directory and files

hdfs dfs -rmr [-skipTrash] URI [URI ...]  ==> usr rm -r
Recursive version of delete.

http://hadoop.apache.org/docs/r2.2.0/hadoop-yarn/hadoop-yarn-site/YarnCommands.html
yarn jar <jar> [mainClass] args
yarn application -list
yarn node -list