about云源码分析之hadoop2.x（2.7.1为例）二次开发：hadoop是如何定义命令行的

接上文
about云源码分析之hadoop2.x（2.7.1为例）二次开发基础：命令行添加
我们有了基础，那么只需要找到hadoop源码是如何添加、定义命令行即可。
同样我们找到宝

package org.apache.hadoop.util中GenericOptionsParser

private static Options buildGeneralOptions(Options opts) {
    Option fs = OptionBuilder.withArgName("local|namenode:port")
    .hasArg()
    .withDescription("specify a namenode")
    .create("fs");
    Option jt = OptionBuilder.withArgName("local|resourcemanager:port")
    .hasArg()
    .withDescription("specify a ResourceManager")
    .create("jt");
    Option oconf = OptionBuilder.withArgName("configuration file")
    .hasArg()
    .withDescription("specify an application configuration file")
    .create("conf");
    Option property = OptionBuilder.withArgName("property=value")
    .hasArg()
    .withDescription("use value for given property")
    .create('D');
    Option libjars = OptionBuilder.withArgName("paths")
    .hasArg()
    .withDescription("comma separated jar files to include in the classpath.")
    .create("libjars");
    Option files = OptionBuilder.withArgName("paths")
    .hasArg()
    .withDescription("comma separated files to be copied to the " +
           "map reduce cluster")
    .create("files");
    Option archives = OptionBuilder.withArgName("paths")
    .hasArg()
    .withDescription("comma separated archives to be unarchived" +
                     " on the compute machines.")
    .create("archives");
    
    // file with security tokens
    Option tokensFile = OptionBuilder.withArgName("tokensFile")
    .hasArg()
    .withDescription("name of the file with the tokens")
    .create("tokenCacheFile");

    opts.addOption(fs);
    opts.addOption(jt);
    opts.addOption(oconf);
    opts.addOption(property);
    opts.addOption(libjars);
    opts.addOption(files);
    opts.addOption(archives);
    opts.addOption(tokensFile);

    return opts;
  }
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