Question

我有以下正则表达式（粗略匹配看起来像URLS的东西）

(https?://\S*)

但是，这是为了在句子中提取URL，因此尾随点可能可能句子的结尾而不是URL的合法部分。

让捕获组忽略尾随句号，逗号，冒号，分号等的神奇咒语是什么？

（我知道匹配的URL是一个噩梦，这只需要支持松散匹配，因此非常简单的正则表达式）

这是我的测试字符串：

lorem http://www.example.com lorem https://example.com lorem 
http://www.example.com.
lorem https://example.com.

这应匹配所有example.com实例。

（我正在用Expresso和.NET测试它）

带尾随点和新行的测试结果：

  Expected string length 62 but was 64. Strings differ at index 31.
  Expected: "<a href="http://www.example.com">http://www.example.com</a>.\n\r"
  But was:  "<a href="http://www.example.com.\n">http://www.example.com.\n</a>\r"
  ------------------------------------------^

示例代码

public class HyperlinkParser
{
    private readonly Regex _regex =
        new Regex(
            @"(https?://\S*[^\.])");

    public string Parse(string original)
    {
        var parsed = _regex.Replace(original, "<a href=\"$1\">$1</a>");
        return parsed;
    }
}

示例测试

[TestFixture]
public class HyperlinkParserTests
{
    private readonly HyperlinkParser _parser = new HyperlinkParser();
    private const string NO_HYPERLINKS = "dummy-text";
    private const string FULL_URL = "http://www.example.com";
    private const string FULL_URL_PARSED = "<a href=\"" + FULL_URL + "\">" + FULL_URL + "</a>";
    private const string FULL_URL_TRAILING_DOT = FULL_URL + ".";
    private const string FULL_URL_TRAILING_DOT_PARSED = "<a href=\"" + FULL_URL + "\">" + FULL_URL + "</a>.";
    private const string TRAILING_DOT_AND_NEW_LINE = FULL_URL_TRAILING_DOT + "\n\r";
    private const string TRAILING_DOT_AND_NEW_LINE_PARSED = FULL_URL_TRAILING_DOT_PARSED + "\n\r";

    private const string COMPLEX_TEXT = "Leading stuff http://www.example.com.  Other stuff.";
    private const string COMPLEX_TEXT_PARSED = "Leading stuff <a href=\"http://www.example.com\">http://www.example.com</a>.  Other stuff.";

    [TestCase(NO_HYPERLINKS, NO_HYPERLINKS)]
    [TestCase(FULL_URL, FULL_URL_PARSED)]
    [TestCase(FULL_URL_TRAILING_DOT, FULL_URL_TRAILING_DOT_PARSED)]
    [TestCase(TRAILING_DOT_AND_NEW_LINE, TRAILING_DOT_AND_NEW_LINE_PARSED)]
    [TestCase(COMPLEX_TEXT, COMPLEX_TEXT_PARSED)]
    public void Parsing(string original, string expected)
    {
        var actual = _parser.Parse(original);

        Assert.That(actual, Is.EqualTo(expected));
    }
}

Answer 1

试试这个，它禁止将dot作为最后一个字符：

(https?://\S*[^.])

E.g。在cygwin下，有egrep：

$ cat ~/tmp.txt
lorem http://www.example.com lorem https://example.com lorem
http://www.example.com.
lorem https://example.com.
$ cat ~/tmp.txt | egrep -o 'https?://\S*[^.]'
http://www.example.com
https://example.com
http://www.example.com
https://example.com

（-o选项告诉egrep只打印匹配。）

如果有的话，正则表达式忽略尾随点

1 个答案: