我正在尝试编写一个替换markdown样式链接的正则表达式,但它似乎不起作用。这就是我到目前为止所做的:
# ruby code:
text = "[link me up](http://www.example.com)"
text.gsub!(%r{\[(\+)\]\((\+)\)}x, %{<a target="_blank" href="\\1">\\2</a>})
我做错了什么?
答案 0 :(得分:38)
irb(main):001:0> text = "[link me up](http://www.example.com)"
irb(main):002:0> text.gsub /\[([^\]]+)\]\(([^)]+)\)/, '<a href="\2">\1</a>'
#=> "<a href=\"http://www.example.com\">link me up</a>"
我们可以使用Ruby的正则表达式的e x
趋势选项,使它看起来不像是跳到键盘上的猫:
def linkup( str )
str.gsub %r{
\[ # Literal opening bracket
( # Capture what we find in here
[^\]]+ # One or more characters other than close bracket
) # Stop capturing
\] # Literal closing bracket
\( # Literal opening parenthesis
( # Capture what we find in here
[^)]+ # One or more characters other than close parenthesis
) # Stop capturing
\) # Literal closing parenthesis
}x, '<a href="\2">\1</a>'
end
text = "[link me up](http://www.example.com)"
puts linkup(text)
#=> <a href="http://www.example.com">link me up</a>
请注意,对于其中包含右括号的网址,上述内容将失败,例如
linkup "[O](http://msdn.microsoft.com/en-us/library/ms533050(v=vs.85).aspx)"
# <a href="http://msdn.microsoft.com/en-us/library/ms533050(v=vs.85">O</a>.aspx)
如果这对您很重要,请将[^)]+
替换为\S+(?=\))
,这意味着“找到尽可能多的非空白字符,但请确保存在)
1}}之后“。
要回答你的问题“我做错了什么”,这就是你的正则表达式所说的:
%r{
\[ # Literal opening bracket (good)
( # Start capturing (good)
\+ # A literal plus character (OOPS)
) # Stop capturing (good)
\] # Literal closing bracket (good)
\( # Literal opening paren (good)
( # Start capturing (good)
\+ # A literal plus character (OOPS)
) # Stop capturing (good)
\) # Literal closing paren (good)
}x