如果该命令不确定类的位置，将打开一个窗口并显示一列可以进行选择的选项。
If the command is unsure about the class's location, a window opens with a list of options for you to choose from.
为了生成运行更加快捷并易于维护的代码，使用散列表存储命令行选项并使用散列验证用户指定的输入，这种方法非常有帮助。
To produce code that runs faster and is easy to maintain, it makes far more sense to use a hash table that stores the command-line options, then USES the hash to validate the user-specified input.
在清单18中，列出了所有运行getty命令的进程；我们使用- o选项来自指定将要显示的列。
In Listing 18, all processes running the getty command are listed; we use the -o option to specify the columns that will be displayed.
编译器选项可以在开发环境中设定，也可以在命令列设定。
Compiler options can be set either in the development environment or on the command line.
编译器选项可以在开发环境中设定，也可以在命令列设定。
Compiler options can be set either in the development environment or on the command line.
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