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  1. Hadoop Common
  2. HADOOP-9267

hadoop -help, -h, --help should show usage instructions

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Minor
    • Resolution: Fixed
    • Affects Version/s: 3.0.0-alpha1
    • Fix Version/s: 2.1.0-beta
    • Component/s: None
    • Labels:
      None
    • Target Version/s:
    • Hadoop Flags:
      Reviewed

      Description

      It's not friendly for new users when the command line scripts don't show usage instructions when passed the defacto Unix usage flags. Imagine this sequence of commands:

      -> % hadoop --help
      Error: No command named `--help' was found. Perhaps you meant `hadoop -help'
      -> % hadoop -help
      Error: No command named `-help' was found. Perhaps you meant `hadoop help'
      -> % hadoop help
      Exception in thread "main" java.lang.NoClassDefFoundError: help
      Caused by: java.lang.ClassNotFoundException: help
      	at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
      	at java.security.AccessController.doPrivileged(Native Method)
      	at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
      	at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
      	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
      	at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
      Could not find the main class: help.  Program will exit.
      

      Same applies for the `hdfs` script.

        Attachments

        1. hadoop-9267-1.patch
          1 kB
          Andrew Wang
        2. hadoop-9267-2.patch
          2 kB
          Andrew Wang

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            • Assignee:
              andrew.wang Andrew Wang
              Reporter:
              andrew.wang Andrew Wang
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              Dates

              • Created:
                Updated:
                Resolved: