export HADOOP_HOME=/usr/local/hadoop
 export PATH=$PATH:$HADOOP_HOME/bin
 export PATH=$PATH:$HADOOP_HOME/sbin
 export HADOOP_MAPRED_HOME=${HADOOP_HOME}
 export HADOOP_COMMON_HOME=${HADOOP_HOME}
 export HADOOP_HDFS_HOME=${HADOOP_HOME}
 export YARN_HOME=${HADOOP_HOME}