sudo tar -zxvf hadoop-3.1.2.tar.gz -C /usr/local/

sudo mv hadoop-3.1.2/ ./hadoop

sudo chown -R hosea ./hadoop/
ls -al

vim ./etc/hadoop/hadoop-env.sh
export JAVA_HOME=/usr/local/jdk/jdk1.8.0_212

vim ./etc/hadoop/core-site.xml

<configuration>
        <property>
                <name>fs.defaultFS</name>
                <value>hdfs://localhost:9000</value>
        </property>
</configuration>

vim ./etc/hadoop/hdfs-site.xml

<configuration>
        <property>
                <name>dfs.replication</name>
                <value>1</value>
        </property>
</configuration>

ssh-keygen -t rsa -P '' -f ~/.ssh/id_rsa
cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
chmod 0600 ~/.ssh/authorized_keys

./bin/hdfs namenode -format
./sbin/start-dfs.sh
./bin/hdfs dfs -mkdir /user
./bin/hdfs dfs -mkdir /user/hosea

./bin/hdfs dfs -mkdir input
./bin/hdfs dfs -put etc/hadoop/*.xml input
./bin/hadoop jar share/hadoop/mapreduce/hadoop-mapreduce-examples-3.1.2.jar grep input output 'dfs[a-z.]+'
./bin/hdfs dfs -get output output
cat output/*