红宝石 - 替换根路径的新根路径

Question

好吧，所以我想采取我有的文件路径，删除已知的根路径，并追加一个新的。

我会尝试打一个比方：

# This one is a path object 
original_path = '/home/foo/bar/path/to/file.txt' 
# This one is a string 
root_path = '/home/foo/bar/' 
# This is also a string 
new_root = '/home/new/root/' 

所以，我有original_path，这是一个路径对象。我想从中删除root_path，并在其前面应用new_root。我怎样才能做到这一点？

编辑：

这是我真正的问题，对不起，以前穷的解释：

require 'pathname' 

# This one is a path object 
original_path = Pathname.new('/home/foo/bar/path/to/file.txt') 
# This one is a string 
root_path = '/home/foo/bar/' 
# This is also a string 
new_root = '/home/new/root/' 

现在，你如何替换那些？

Answer 1

如果你只是想获得一个新的字符串，你可以这样做

# This one is a path object 
original_path = '/home/foo/bar/path/to/file.txt' 
# This one is a string 
root_path = '/home/foo/bar/' 
# This is also a string 
new_root = '/home/new/root/' 

new_path = original_path.gsub(root_path, new_root) 

编辑

，您仍然可以使用sub代替gsub如果original_path是Pathname

new_path = original_path.sub(root_path, new_root)