大数据笔记 | HDFS 常用操作命令

一、HDFS 命令前缀

二、ls 命令

三、put 命令

HDFS 是 Hadoop Distributed File System 的简写，即 Hadoop 分布式文件系统。它是 Hadoop 项目的核心子项目，它为大数据分布式计算提供了海量数据的存储与管理。

既然 HDFS 是文件系统，那么它必然有一套对文件管理的命令，这里介绍一下 HDFS 常用的文件管理命令。

一、HDFS 命令前缀

所有操作 HDFS 的命令都需要前缀，它的前缀有两种，分别是 hadoop fs 或 hdfs dfs 两种。可以通过 hadoop fs -help 或 hdfs dfs -help 来查看其帮助文件。比如：

$ hadoop fs -help ls
-ls [-C] [-d] [-h] [-q] [-R] [-t] [-S] [-r] [-u] [<path> ...] :
  List the contents that match the specified file pattern. If path is not
  specified, the contents of /user/<currentUser> will be listed. For a directory a
  list of its direct children is returned (unless -d option is specified).

  Directory entries are of the form:
        permissions - userId groupId sizeOfDirectory(in bytes)
  modificationDate(yyyy-MM-dd HH:mm) directoryName

  and file entries are of the form:
        permissions numberOfReplicas userId groupId sizeOfFile(in bytes)
  modificationDate(yyyy-MM-dd HH:mm) fileName

    -C  Display the paths of files and directories only.
    -d  Directories are listed as plain files.
    -h  Formats the sizes of files in a human-readable fashion
        rather than a number of bytes.
    -q  Print ? instead of non-printable characters.
    -R  Recursively list the contents of directories.
    -t  Sort files by modification time (most recent first).
    -S  Sort files by size.
    -r  Reverse the order of the sort.
    -u  Use time of last access instead of modification for
        display and sorting.

或者使用 hdfs dfs 来查看帮助，命令如下：

$ hdfs dfs -help ls
-ls [-C] [-d] [-h] [-q] [-R] [-t] [-S] [-r] [-u] [<path> ...] :
  List the contents that match the specified file pattern. If path is not
  specified, the contents of /user/<currentUser> will be listed. For a directory a
  list of its direct children is returned (unless -d option is specified).

  Directory entries are of the form:
        permissions - userId groupId sizeOfDirectory(in bytes)
  modificationDa