Perl:如何通过要求脚本中的要求脚本提供变量 [英] Perl: how to make variables from requiring script available in required script

问题描述

示例

out.pl:

(my|our|local|global|whatever???) var = "test";
require("inside.pm");

inside.pm:

inside.pm:

print $var;

我不想使用软件包-它压倒了我的需求:) 谢谢！

I don't want to use packages - it's overwhelming my needs :) thanks!

推荐答案

它将与our一起使用.

$ cat out.pl
our $var = "test";
require("inside.pm");

$ cat inside.pm 
print "Testing...\n";
print "$var\n";

$ perl out.pl
Testing...
test

之所以起作用，是因为our使$var成为全局变量，并且inside.pm在定义了$var的作用域中执行.不确定是否建议使用该技术，但这仍然是一个有趣的问题！

This works because our makes $var global, and inside.pm is being executed in the scope with $var defined. Not sure it is recommended technique, but it is an interesting question nevertheless!

编辑:需要根据评论来澄清(好的补丁)答案:

EDIT: Need to clarify (okay patch) the answer based on a comment:

来自有关Perl函数our 的文档:

From the documentation on the Perl function our:

our将简单名称与当前包中的包(读取:全局)变量相关联，以在当前词法范围内使用.换句话说，our具有与my或state相同的作用域规则，但不一定创建变量.

our associates a simple name with a package (read: global) variable in the current package, for use within the current lexical scope. In other words, our has the same scoping rules as my or state, but does not necessarily create a variable.

因此，使用our，我们将使用当前软件包(此处可能是main)获得$var，并且可以在其范围内使用它.实际上，它是您需要输入的文件中的代码的全局".

So using our, we get $var with the current package (here probably main) and we can use it in its scope. In effect it is then "global" to the code in the file you are requiring-in.

引入了 true全局，而没有our，因为变量默认为global.但是我不认识会推荐他们的人.

A true global is introduced without the our, because variables default to global. But I don't know anyone that would recommend them.

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