Perl:如何在许多独立脚本之间共享大量模块的导入? [英] Perl: how to share the import of a large list of modules between many independent scripts?

问题描述

我有很多独立脚本.它们唯一共享的是，它们使用()大量的CPAN模块(每个模块都导出多个功能).我想集中列出这些模块.我发现了几种方法.哪一个最好?

I have many standalone scripts. The only thing they share, is that they use() a large set of CPAN modules (that each export several functions). I would like to centralize this list of modules. I found several methods. Which one is the best?

1. 我可以创建SharedModules.pm来导入所有内容，然后使用Exporter将所有内容手动导出到main ::.

1. I could create SharedModules.pm that imports everything and then manually exports everything to main:: using Exporter.

我可以创建以"package main;"开头的SharedModules.pm.因此它将直接导入main ::.看来行得通.这是不好的做法吗?为什么?

I could create SharedModules.pm that starts with "package main;" so it will import directly into main::. It seems to work. Is it bad practice and why?

我可能需要()一个sharedmodules.pl，似乎也将所有内容导入到main ::中.我不喜欢这种方法，因为require()在mod_perl下无法正常工作.

I could require() a sharedmodules.pl that seems to import everything into main:: as well. I don't like this method as require() doesn't work that well under mod_perl.

第二个对我来说看起来最好，但是我想知道为什么Modern :: Perl不能那样工作.

Number two looks best to me, however I wonder why for example Modern::Perl doesn't work that way.

我认为这个问题是

I figured this question has been asked before.

推荐答案

您提出的所有三种解决方案的问题是，该模块可能是从另一个模块中use d的，在这种情况下，应将符号导出到use正在添加模块的软件包，而不是放入main.

The problem with all three of your proposed solutions is that the module may be used from another module, in which case the symbols should be exported into the useing module's package, not into main.

bvr使用caller直接将内容导入该程序包的解决方案是朝正确方向迈出的重要一步，但阻止了真实"程序包使用use ShareableModules qw( foo bar baz);仅选择性地导入其实际需要的内容.

bvr's solution of using caller to import things directly into that package is a major step in the right direction, but prevents the 'real' package from using use ShareableModules qw( foo bar baz); to selectively import only what it actually needs.

不幸的是，要保留选择性导入的能力，将需要您从基础模块中导入所有相关符号，然后从ShareableModules中重新导出它们.您不能仅将导入委派给每个基础模块的import方法(如Modern::Perl一样)，因为如果import要求输入不由该模块导出的符号，则会死掉.但是，如果这不是问题，那么Modern::Perl的处理方式可能是最干净，最简单的选择.

Unfortunately, preserving the ability to import selectively will require you to import all relevant symbols from the underlying modules and then re-export them from ShareableModules. You can't just delegate the import to each underlying module's import method (as Modern::Perl does) because import dies if it's asked for a symbol that isn't exported by that module. If that's not an issue, though, then Modern::Perl's way of doing it is probably the cleanest and simplest option.

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