HFDS的Shell操作
1．基本语法
bin/hadoop fs 具体命令
2．命令大全
[atguigu@hadoop102 hadoop-2.7.2]$ bin/hadoop fs

    [-appendToFile <localsrc> ... <dst>]
    [-cat [-ignoreCrc] <src> ...]
    [-checksum <src> ...]
    [-chgrp [-R] GROUP PATH...]
    [-chmod [-R] <MODE[,MODE]... | OCTALMODE> PATH...]
    [-chown [-R] [OWNER][:[GROUP]] PATH...]
    [-copyFromLocal [-f] [-p] <localsrc> ... <dst>]
    [-copyToLocal [-p] [-ignoreCrc] [-crc] <src> ... <localdst>]
    [-count [-q] <path> ...]
    [-cp [-f] [-p] <src> ... <dst>]
    [-createSnapshot <snapshotDir> [<snapshotName>]]
    [-deleteSnapshot <snapshotDir> <snapshotName>]
    [-df [-h] [<path> ...]]
    [-du [-s] [-h] <path> ...]
    [-expunge]
    [-get [-p] [-ignoreCrc] [-crc] <src> ... <localdst>]
    [-getfacl [-R] <path>]
    [-getmerge [-nl] <src> <localdst>]
    [-help [cmd ...]]
    [-ls [-d] [-h] [-R] [<path> ...]]
    [-mkdir [-p] <path> ...]
    [-moveFromLocal <localsrc> ... <dst>]
    [-moveToLocal <src> <localdst>]
    [-mv <src> ... <dst>]
    [-put [-f] [-p] <localsrc> ... <dst>]
    [-renameSnapshot <snapshotDir> <oldName> <newName>]
    [-rm [-f] [-r|-R] [-skipTrash] <src> ...]
    [-rmdir [--ignore-fail-on-non-empty] <dir> ...]
    [-setfacl [-R] [{-b|-k} {-m|-x <acl_spec>} <path>]|[--set <acl_spec> <path>]]
    [-setrep [-R] [-w] <rep> <path> ...]
    [-stat [format] <path> ...]
    [-tail [-f] <file>]
    [-test -[defsz] <path>]
    [-text [-ignoreCrc] <src> ...]
    [-touchz <path> ...]
    [-usage [cmd ...]]

3．常用命令实操
（0）启动Hadoop集群（方便后续的测试）

    [atguigu@hadoop102 hadoop-2.7.2]$ sbin/start-dfs.sh
    [atguigu@hadoop103 hadoop-2.7.2]$ sbin/start-yarn.sh

（1）-help：输出这个命令参数

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -help rm

（2）-ls: 显示目录信息

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -ls /

（3）-mkdir：在hdfs上创建目录

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -mkdir -p /sanguo/shuguo

（4）-moveFromLocal从本地剪切粘贴到hdfs

    [atguigu@hadoop102 hadoop-2.7.2]$ touch kongming.txt
    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs  -moveFromLocal  ./kongming.txt  /sanguo/shuguo

（5）-appendToFile ：追加一个文件到已经存在的文件末尾

    [atguigu@hadoop102 hadoop-2.7.2]$ touch liubei.txt
    [atguigu@hadoop102 hadoop-2.7.2]$ vi liubei.txt

输入
san gu mao lu

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -appendToFile liubei.txt /sanguo/shuguo/kongming.txt

（6）-cat：显示文件内容

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -cat /sanguo/shuguo/kongming.txt

（7）-tail：显示一个文件的末尾

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -tail /sanguo/shuguo/kongming.txt

（8）-chgrp 、-chmod、-chown：linux文件系统中的用法一样，修改文件所属权限

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs  -chmod  666  /sanguo/shuguo/kongming.txt
    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs  -chown  atguigu:atguigu   /sanguo/shuguo/kongming.txt

（9）-copyFromLocal：从本地文件系统中拷贝文件到hdfs路径去

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -copyFromLocal README.txt /

（10）-copyToLocal：从hdfs拷贝到本地

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -copyToLocal /sanguo/shuguo/kongming.txt ./

（11）-cp ：从hdfs的一个路径拷贝到hdfs的另一个路径

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -cp /sanguo/shuguo/kongming.txt /zhuge.txt

（12）-mv：在hdfs目录中移动文件

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -mv /zhuge.txt /sanguo/shuguo/

（13）-get：等同于copyToLocal，就是从hdfs下载文件到本地

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -get /sanguo/shuguo/kongming.txt ./

（14）-getmerge ：合并下载多个文件，比如hdfs的目录 /aaa/下有多个文件:log.1, log.2,log.3,...

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -getmerge /user/atguigu/test/* ./zaiyiqi.txt

（15）-put：等同于copyFromLocal

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -put ./zaiyiqi.txt /user/atguigu/test/

（16）-rm：删除文件或文件夹

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -rm /user/atguigu/test/jinlian2.txt

（17）-rmdir：删除空目录

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -mkdir /test
    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -rmdir /test

（18）-du统计文件夹的大小信息

    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -du -s -h /user/atguigu/test
    2.7 K  /user/atguigu/test
    [atguigu@hadoop102 hadoop-2.7.2]$ hadoop fs -du  -h /user/atguigu/test
    1.3 K  /user/atguigu/test/README.txt
    15     /user/atguigu/test/jinlian.txt
    1.4 K  /user/atguigu/test/zaiyiqi.txt