Usage: hadoop fs [generic options]
[-appendToFile ... ]
[-cat [-ignoreCrc] ...]
[-checksum ...]
[-chgrp [-R] GROUP PATH...]
[-chmod [-R] <MODE[,MODE]... | OCTALMODE> PATH...]
[-chown [-R] [OWNER][:[GROUP]] PATH...]
[-copyFromLocal [-f] [-p] [-l] [-d] [-t ] ... ]
[-copyToLocal [-f] [-p] [-ignoreCrc] [-crc] ... ]
[-count [-q] [-h] [-v] [-t []] [-u] [-x] [-e] ...]
[-cp [-f] [-p | -p[topax]] [-d] ... ]
[-createSnapshot []]
[-deleteSnapshot ]
[-df [-h] [ ...]]
[-du [-s] [-h] [-v] [-x] ...]
[-expunge]
[-find ... ...]
[-get [-f] [-p] [-ignoreCrc] [-crc] ... ]
[-getfacl [-R] ]
[-getfattr [-R] {-n name | -d} [-e en] ]
[-getmerge [-nl] [-skip-empty-file] ]
[-head ]
[-help [cmd ...]]
[-ls [-C] [-d] [-h] [-q] [-R] [-t] [-S] [-r] [-u] [-e] [ ...]]
[-mkdir [-p] ...]
[-moveFromLocal ... ]
[-moveToLocal ]
[-mv ... ]
[-put [-f] [-p] [-l] [-d] ... ]
[-renameSnapshot ]
[-rm [-f] [-r|-R] [-skipTrash] [-safely] ...]
[-rmdir [--ignore-fail-on-non-empty] ...]
[-setfacl [-R] [{-b|-k} {-m|-x <acl_spec>} ]|[--set <acl_spec> ]]
[-setfattr {-n name [-v value] | -x name} ]
[-setrep [-R] [-w] ...]
[-stat [format] ...]
[-tail [-f] [-s ] ]
[-test -[defsz] ]
[-text [-ignoreCrc] ...]
[-touch [-a] [-m] [-t TIMESTAMP ] [-c] ...]
[-touchz ...]
[-truncate [-w] ...]
[-usage [cmd ...]]
Generic options supported are:
-conf specify an application configuration file
-D <property=value> define a value for a given property
-fs file:///|hdfs://namenode:port specify default filesystem URL to use, overrides 'fs.defaultFS' property from configurations.
-jt <local|resourcemanager:port> specify a ResourceManager
-files <file1,...> specify a comma-separated list of files to be copied to the map reduce cluster
-libjars <jar1,...> specify a comma-separated list of jar files to be included in the classpath
-archives <archive1,...> specify a comma-separated list of archives to be unarchived on the compute machines
The general command line syntax is:
command [genericOptions] [commandOptions]
hadoop fs -appendToFile 命令
"hdfs -appendToFile"命令用于Hadoop分布式文件系统（HDFS）中的文件追加操作。它允许您将内容追加到现有文件的末尾，而不会覆盖现有数据。
以下是该命令的一般语法：
hadoop fs -appendToFile
是您要追加到HDFS文件的本地文件或目录。 指定了HDFS中要追加数据的目标文件。 例如，如果您的本地机器上有一个名为"data.txt"的文件，您想将其内容追加到HDFS中的一个名为"hdfsfile.txt"的现有文件中，您可以使用以下命令：
hadoop fs -appendToFile data.txt hdfs://localhost:9000/user/hadoop/hdfsfile.txt
请确保将HDFS文件路径（hdfs://localhost:9000/user/hadoop/hdfsfile.txt）替换为实际的HDFS目标文件路径。
请注意，您需要具有写入HDFS文件的必要权限。
hadoop -cat 命令