Hadoop command line samples

Refer to the following command to set or export your HADOOP_HOME environment variable.

set HADOOP_HOME=C:\java\hadoop-2.2.0
export HADOOP_HOME="/home/victortch/java/hadoop-2.2.0"

Use the following command to set or export a PATH to include the Hadoop bin folder:

set PATH=%PATH%;%HADOOP_HOME%\bin
export PATH=$PATH:$HADOOP_HOME/bin

Use the following command to check the Hadoop version:

hadoop version
Hadoop 2.2.0
Subversion https://svn.apache.org/repos/asf/hadoop/common -r 1529768
Compiled by hortonmu on 2013-10-07T06:28Z
Compiled with protoc 2.5.0
From source with checksum 79e53ce7994d1628b240f09af91e1af4
This command was run using /C:/java/hadoop-2.2.0/share/hadoop/common/hadoop-comm on-2.2.0.jar

$ hadoop version
Hadoop 2.2.0
Subversion https://svn.apache.org/repos/asf/hadoop/common -r 1529768
Compiled by hortonmu on 2013-10-07T06:28Z
Compiled with protoc 2.5.0
From source with checksum 79e53ce7994d1628b240f09af91e1af4
This command was run using
/home/victortch/java/hadoop-2.2.0/share/hadoop/common/hadoop-common-2.2.0.jar

Use the following command to copy the remote HDFS server file to a local folder:

hadoop fs -copyToLocal  hdfs://labhadoop01:8020/user/devuser/README.txt

Use the following command to copy the local file to a remote HDFS server with forced override.

hadoop fs -copyFromLocal -f README.txt hdfs://labhadoop01:8020/user/devuser