A.hdfs dfs-cat test/readme.txt B.hdfs dfs-put test/readme.txt C.hdfs dfs-rm-R test/readme.txt D.hdfs dfs-copyFromLocal readme.txt test
A.hdfs dfs-ls test B.hdfs dfs-mkdir test C.hdfs dfs-cat test D.hdfs dfs-put test
A.讀 B.寫 C.隨機讀 D.合并