ruby - $:<< "." do to Ruby's require path? 是什么意思

Question

我不明白$:<< "."的意思在 Ruby 中。

我将 Ruby 升级到 1.9.1，但程序无法运行。我的同学告诉我，我应该添加 $:<< "."

什么是$:<< "."做？

Answer 1

1. $:是包含构成 Ruby 加载路径的路径数组的变量
2. <<将一个项目追加到数组的末尾

3. .引用当前目录

   1   2  3
   |   |  |
   V   V  V
   $: << "."
   

所以你正在将当前目录添加到 Ruby 的加载路径

引用资料:

1. 可以在 Execution Environment Variables 中找到此页面的一部分来自 The Pragmatic Programmers Guide

   An array of strings, where each string specifies a directory to be searched for Ruby scripts and binary extensions used by the load and require methods. The initial value is the value of the arguments passed via the -I command-line option, followed by an installation-defined standard library location, followed by the current directory (“.”)[Obviously this link is for an older version of Ruby as this is still in there]. This variable may be set from within a program to alter the default search path; typically, programs use $: << dir to append dir to the path.

2. 可以在 docs for array 中找到在 ruby​​-doc.org。

   Append—Pushes the given object on to the end of this array. This expression returns the array itself, so several appends may be chained together.