zsh中第三个参数的自动完成功能

Question

我是一名有用的助手，可以为您翻译文本。

我有一个shell脚本，它的使用方法如下：

foo.sh <name> <type> <*.tar.gz>

我希望只使用第三个参数来设置完整内容。如果我按下第一个参数，只显示用法。

我能否使用zsh的zshcomp来完成这项工作？

例如：

foo.sh <tab>  # display usage
foo.sh a b <tab> # show files match with *.tar.gz

有没有类似的脚本可以供我参考？

- Daniel YC Lin

Answer 1

需要阅读的内容

这篇博客文章讨论了Z-Shell Completion System。

如果您想要更深入的讨论，请阅读这个unix.stackexchange的回答。

同时，阅读man pages！

编辑：忘记补充了：echo $fpath会显示zsh使用的函数路径。在OSX上，我有：/usr/local/share/zsh/4.3.17/functions（可能因人而异），其中包含所有的ZSH完成函数。查看一下_ssh、_ls、_tar等文件——它们都在那里，并且它们都有很多巧妙的功能可以学习。

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回答问题：你应该去的方向。

虽然需要几个步骤，但你所问的是可以实现的。

1. You need to write a z-shell completion function. It needs to be located on the fpath; the function-path that zsh uses for it's completion system functions. (If it's a small function, putting it into ~/.zshrc will also work, but isn't recommended).

2. You want completion on the 3rd parameter. To do that, your function would look something like the following:

   _arguments "3:<MENU>:<COMPLETION>"
   

   <MENU> is the menu description, which you'll see if you've enabled the menu descriptions. (That's done using zstyle; read the man pages, or the linked pages, for more information). <COMPLETION> is the things that you can complete with. For example, if you used:

   _arguments "3::(Foo Bar)"
   

   when you ran your script and pressed <TAB>, you'd have the option of either Foo or Bar. [NOTE: There is no <MENU> in that example. If you don't want a menu descriptor, you can omit it as shown].

3. You want completion on *.tar files. You can call _files to do that:

   _files -g \*.tar
   

4. Show usage on first parameter: that'd be a completion with no arguments (ie, argument 1). I'm not sure why you'd want completion on only the third option but not the first two (typical usage descriptions), so I don't know how to answer this. If your script is supposed to be used like this: script foo bar FILE.tar, wouldn't you want to complete the foo and bar arguments as well?
   Perhaps a better solution would be displaying the usage when the script is run without parameters.

完整的脚本应该如下所示：

#compdef myscript

_arguments "3:tar files:_files -g \*.tar"

- simont

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请注意，对于我来说 _arguments "3::(Foo Bar)" 不起作用。应该在冒号之间有空格，即 _arguments "3: :(Foo Bar)"。 - Aleksey