使用Apache common-cli解析参数 [英] Using Apache common-cli to parse arguments

问题描述

Apache common-cli在其网站上有一个ls命令的示例:

Apache common-cli has a example on its web site for ls command:

options.addOption( "a", "all", false, "do not hide entries starting with ." );
options.addOption( "A", "almost-all", false, "do not list implied . and .." );
options.addOption( "b", "escape", false, "print octal escapes for nongraphic " + "characters" );
options.addOption( OptionBuilder.withLongOpt( "block-size" )
                                .withDescription( "use SIZE-byte blocks" )
                                .hasArg()
                                .withArgName("SIZE")
                                .create() );

这显示了这样的帮助:

-a, --all                  do not hide entries starting with .
-A, --almost-all           do not list implied . and ..
-b, --escape               print octal escapes for nongraphic characters
    --block-size=SIZE      use SIZE-byte blocks

1. 编写此代码时，它显示--block-size <SIZE>.我想显示这样的内容:-z,--block-size=SIZE(不只是 长选项).
2. PosixParser和GnuParser有什么区别?我变了 他们在代码中，我没有发现任何区别.
3. 例如，当我提供错误的选项h时，它不会throw任何ParseException.该程序将正常启动和结束.

1. When I write this code, it shows --block-size <SIZE>. I want to show something like this: -z,--block-size=SIZE(not just long option).
2. what is the difference of PosixParser and GnuParser? I changed them in the code, I didn't observed any difference.
3. When I provide wrong option for example h it doesn't throw any ParseException. The program starts and finishes normally.

推荐答案

1. 示例中的块大小选项只有长格式，这就是为什么没有显示短选项的原因.如果添加简短的别名，您将获得预期的结果

1. The block size option in the example has only a long format, that's why there is no short option shown. If you add a short alias you'll get the result you expect

PosixParser和GnuParser.一个新的统一解析器作为DefaultParser可用. posix解析器能够解析串联的短选项，例如tar -zxvf foo.tar.gz.

PosixParser and GnuParser are deprecated in the latest version of Commons CLI. A new unified parser is available as DefaultParser. The posix parser had the ability to parse concatenated short options, something like tar -zxvf foo.tar.gz.

其他选项要么作为应用程序的参数处理，要么触发异常，具体取决于stopAtNonOption解析器参数的值.

Extra options are either handled as arguments to the application or trigger an exception, depending of the value of the stopAtNonOption parser parameter.

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