ruby - Pry 中的 ls 命令如何接受 -l 作为参数？

Question

我最近发现 pry 中的 ls 可以采用如下参数:ls -l。

我最初的问题是 -l 部分实际上是什么 - 它显然不是字符串或符号，并且没有定义局部变量或方法 l ，所以幕后还有其他事情发生吗？

作为我的问题的扩展，ls 只是 pry 定义的“正常”Ruby 方法，还是它的行为略有不同？

我还注意到，如果传递字符串 (ls 'l') 或符号 (ls :l)，您会得到不同的输出。是否有可能选项的完整引用？

Answer 1

传递 -l 的作用是通过 pry_eval 方法将整行计算为字符串。从这里开始，它将开头与现有命令进行匹配，并提取其余部分作为要传入的选项。来自 Pry 文档:

Nearly every piece of functionality in a Pry session is implemented as a command. Commands are not methods and must start at the beginning of a line, with no whitespace in between. Commands support a flexible syntax and allow 'options' in the same way as shell commands

您可以通过运行ls -h来查看完整的选项列表。这将返回:

-m, --methods               Show public methods defined on the Object (default)
-M, --instance-methods      Show methods defined in a Module or Class
-p, --ppp                   Show public, protected (in yellow) and private (in green) methods
-q, --quiet                 Show only methods defined on object.singleton_class and object.class
-v, --verbose               Show methods and constants on all super-classes (ignores Pry.config.ls.ceiling)
-g, --globals               Show global variables, including those builtin to Ruby (in cyan)
-l, --locals                Show locals, including those provided by Pry (in red)
-c, --constants             Show constants, highlighting classes (in blue), and exceptions (in purple)
-i, --ivars                 Show instance variables (in blue) and class variables (in bright blue)
-G, --grep                  Filter output by regular expression
-h, --help                  Show this message.