pig的基本操作介绍

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pig是什么？

我的理解是： pig就相当于 shell ,  hadoop就相当于linux  (所以我尽可能的会使用pig操作hadoop的文件)

1.进入HADOOP_HOME目录。
2.执行sh bin/hadoop
我们可以看到更多命令的说明信息：
Usage: hadoop [--config confdir] COMMAND
where COMMAND is one of:
  namenode -format     format the DFS filesystem
  secondarynamenode    run the DFS secondary namenode
  namenode             run the DFS namenode
  datanode             run a DFS datanode
  dfsadmin             run a DFS admin client
  fsck                 run a DFS filesystem checking utility
  fs                   run a generic filesystem user client
  balancer             run a cluster balancing utility
  jobtracker           run the MapReduce job Tracker node
  pipes                run a Pipes job
  tasktracker          run a MapReduce task Tracker node
  job                  manipulate MapReduce jobs
  queue                get information regarding JobQueues
  version              print the version
  jar            run a jar file
  distcp copy file or directories recursively
  archive -archiveName NAME * create a hadoop archive
  daemonlog            get/set the log level for each daemon
 or
  CLASSNAME            run the class named CLASSNAME
Most commands print help when invoked w/o parameters.

常用pig命令

ls/ pwd/ cd 

例如： 查看文件大小

grunt> fs -du -h -s 文件名
19.4 G  文件名

grunt> help

Commands:
; - See the PigLatin manual for details: http://hadoop.apache.org/pig
File system commands:
    fs - Equivalent to Hadoop dfs command: http://hadoop.apache.org/common/docs/current/hdfs_shell.html
Diagnostic commands:
    describe [::    explain [-script ] [-out ] [-brief] [-dot|-xml] [-param =]
        [-param_file ] [] - Show the execution plan to compute the alias or for entire script.
        -script - Explain the entire script.
        -out - Store the output into directory rather than print to stdout.
        -brief - Don't expand nested plans (presenting a smaller graph for overview).
        -dot - Generate the output in .dot format. Default is text format.
        -xml - Generate the output in .xml format. Default is text format.
        -param         -param_file - See parameter substitution for details.
        alias - Alias to explain.
    dump - Compute the alias and writes the results to stdout.
Utility Commands:
    exec [-param =param_value] [-param_file ]