Erlang正则表达式的例子

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本文介绍在Zotonic源代码中如何运用正则表达式进行字符串匹配及分割操作，并通过示例展示了正则表达式的编译与运行过程。

http://zotonic.com/documentation/908/just-enough-zotonic-source-part-3-regular-expressions

27> re:run("E-mail: xyz@pdq.com", "[a-zA-Z0-9]+@[a-zA-Z0-9]+\.[a-z]{2,3}").
{match,[{8,11}]}

Note: DO NOT use this pattern in production. It needs more refinement and much more testing.

What other goodies does re offer?

split(Subject, RE) -> SplitList

and

split(Subject, RE, Options) -> SplitList

Examples:

28> re:split("this/is/my/path","/").
[<<"this">>,<<"is">>,<<"my">>,<<"path">>]

If you wish to use a pattern multiple times and boost perfomance, you can compile it with re:compile/1.

Example:

29>  {_, P} = re:compile("[a-zA-Z0-9]+@[a-zA-Z0-9]+\.[a-z]{2,3}").
{ok,{re_pattern,0,0,
                <<69,82,67,80,164,0,0,0,0,0,0,0,5,0,0,0,0,0,0,0,0,0,64,
                  ...>>}}
30> re:run("E-mail: xyz@pdq.com", P).
{match,[{8,11}]}

How are regular expressions used in Zotonic source?

For one of many examples, look at ../zotonic/src/markdown/get_url/1.

get_url(String) ->
    HTTP_regex = "^(H|h)(T|t)(T|t)(P|p)(S|s)*://",
    case re:run(String, HTTP_regex) of
        nomatch    -> not_url;
        {match, _} -> get_url1(String, [])
    end.