熟悉常用的HDFS操作

cd /usr/local/hadoop
touch linux.txt
cat linux.txt

./sbin/start-dfs.sh
./bin/hdfs dfs -mkdir -p /user/hadoop
./bin/hdfs dfs -mkdir input
./bin/hdfs dfs -put ./linux.txt input

./bin/hdfs dfs -ls    
./bin/hdfs dfs -ls input

./bin/hdfs dfs -cat input/linux.txt

./bin/hdfs dfs -rm -ls input/linux.txt

./bin/hdfs dfs -get input/test.txt ~/linux.txt

if $(hdfs dfs -test -e text.txt);
then $(hdfs dfs -appendToFile local.txt text.txt);
else $(hdfs dfs -copyFromLocal -f local.txt text.txt);
fi

if $(hdfs dfs -test -e file:///usr/hadoop/text.txt);
then $(hdfs dfs -copyToLocal text.txt ./text2.txt); 
else $(hdfs dfs -copyToLocal text.txt ./text.txt); 
fi

hdfs dfs -cat text.txt

hdfs dfs -ls -h text.txt

hdfs dfs -ls -R -h /user/hadoop

if $(hdfs dfs -test -d dir1/dir2);
then $(hdfs dfs -touchz dir1/dir2/filename); 
else $(hdfs dfs -mkdir -p dir1/dir2 && hdfs dfs -touchz dir1/dir2/filename); 
fi
删除文件：hdfs dfs -rm dir1/dir2/filename

创建目录：hdfs dfs -mkdir -p dir1/dir2
删除目录（如果目录非空则会提示not empty，不执行删除）：hdfs dfs -rmdir dir1/dir2
强制删除目录：hdfs dfs -rm -R dir1/dir2

追加到文件末尾：hdfs dfs -appendToFile local.txt text.txt
追加到文件开头：
（由于没有直接的命令可以操作，方法之一是先移动到本地进行操作，再进行上传覆盖）：
hdfs dfs -get text.txt
cat text.txt >> local.txt
hdfs dfs -copyFromLocal -f text.txt text.txt

hdfs dfs -rm text.txt

删除目录（如果目录非空则会提示not empty，不执行删除）：hdfs dfs -rmdir dir1/dir2
强制删除目录：hdfs dfs -rm -R dir1/dir2

hdfs dfs -mv text.txt text2.txt