如果没有，是否存在一个事实上的标准?基本上，我正在编写命令行帮助文本，如下所示:
usage: app_name [options] required_input required_input2
options:
-a, --argument Does something
-b required Does something with "required"
-c, --command required Something else
-d [optlistitem1 optlistitem 2 ... ] Something with list
我基本上只是阅读了各种工具的帮助文本，但是否有指南列表或其他内容?例如，我是用方括号还是圆括号?如何使用空格?如果参数是一个列表呢?谢谢!
当前回答
看一下docopt。它是用于记录(和自动解析)命令行参数的正式标准。
例如……
Usage:
my_program command --option <argument>
my_program [<optional-argument>]
my_program --another-option=<with-argument>
my_program (--either-that-option | <or-this-argument>)
my_program <repeating-argument> <repeating-argument>...
其他回答
我会以官方项目为例，比如tar。在我看来，帮助味精。需要尽可能的简单和描述性。使用的例子也很好。对“标准帮助”没有真正的需求。
我认为命令行使用没有标准的语法，但大多数人都使用这样的约定:
微软命令行语法，IBM有类似的命令行语法
没有括号或大括号的文本 必须按所示输入的项 <尖括号内的文本> 必须为其提供值的占位符 [方括号内的文本] 可选项目 {括号内的文本} 一套必需的项目;选择一个 竖条{a|b} 互斥项的分隔符;选择一个 <file>… 可以重复的项目
我们运行的是Linux，一个基本符合posix的操作系统。它应该是POSIX标准:实用程序参数语法。
An option is a hyphen followed by a single alphanumeric character, like this: -o. An option may require an argument (which must appear immediately after the option); for example, -o argument or -oargument. Options that do not require arguments can be grouped after a hyphen, so, for example, -lst is equivalent to -t -l -s. Options can appear in any order; thus -lst is equivalent to -tls. Options can appear multiple times. Options precede other nonoption arguments: -lst nonoption. The -- argument terminates options. The - option is typically used to represent one of the standard input streams.
微软有自己的命令行标准规范:
This document is focused at developers of command line utilities. Collectively, our goal is to present a consistent, composable command line user experience. Achieving that allows a user to learn a core set of concepts (syntax, naming, behaviors, etc) and then be able to translate that knowledge into working with a large set of commands. Those commands should be able to output standardized streams of data in a standardized format to allow easy composition without the burden of parsing streams of output text. This document is written to be independent of any specific implementation of a shell, set of utilities or command creation technologies; however, Appendix J - Using Windows Powershell to implement the Microsoft Command Line Standard shows how using Windows PowerShell will provide implementation of many of these guidelines for free.
没有标准，但是http://docopt.org/已经创建了他们版本的命令行工具的帮助文本规范。
