正则表达式匹配字符串

时间：2016-07-06 23:56:25

标签： php regex

我正在开发PHP中的“文字过滤器”类，除其他外，需要捕获故意拼写错误的单词。这些单词由用户输入为句子。让我展示一个用户输入的句子的简单例子：

I want a coke, sex, drugs and rock'n'roll

以上示例是正确的短语写法。我的班级会找到可疑的单词sex和drugs，并且会很好。

但我认为用户会试图阻止对单词的检测并将内容写得稍微不同。实际上，他有许多不同的方法来编写相同的单词，以便它对某些类型的人仍然可读。例如，单词sex可以写为s3x或5ex或53x或s e x或s 3 x或s33x或5533xxx ss 33 xxx等等。

我知道正则表达式的基础知识并尝试了下面的模式：

/(\b[\w][\w .'-]+[\w]\b)/g

因为

  • \b字边界
  • [\w]这个词可以以一个字母或一个数字开头......
  • [\w .'-] ...后跟任何字母，数字，空格，点，引号或破折号......
  • + ...一次或多次......
  • [\w] ...以一个字母或一个数字结尾。
  • \b字边界

这部分有效。

如果示例短语写为I want a coke, 5 3 x, druuu95 and r0ck'n'r011，我会得到3个匹配项：

  • I want a coke
  • 5 3 x
  • druuu95 and r0ck'n'r011

我需要的是8场比赛

  • I
  • want
  • a
  • coke
  • 5 3 x
  • druuu95
  • and
  • r0ck'n'r011

为了缩短，我需要一个正则表达式给我一个句子的每个单词，即使单词以数字开头，包含可变数量的数字，空格，点，短划线和引号，并以字母结尾或数字。

任何帮助将不胜感激。

1 个答案:

答案 0 :(得分：3)

描述

通常好的单词长度为2个或更多字母（I和a除外）并且不包含数字。这种表达方式并不完美，但确实有助于说明为什么进行这种类型的语言匹配是非常困难的，因为它是创造性的人试图表达自己而不被抓住之间的军备竞赛，以及正在尝试的开发团队抓住瑕疵。

(?:\s+|\A)[#'"[({]?(?!(?:[a-z]{2}\s+){3})(?:[a-zA-Z'-]{2,}|[ia]|i[nst]|o[fnr])[?!.,;:'")}\]]?(?=(?:\s|\Z))|((?:[a-z]{2}\s+){3}|.*?\b)

Regular expression visualization

**要更好地查看图像，只需右键单击图像并在新窗口中选择视图

此正则表达式将执行以下操作：

  • 找到所有可接受的单词
  • 查找所有其余内容并将其存储在Capture Group 1
    • 中

实施例

现场演示

https://regex101.com/r/cL2bN1/1

解释

NODE                     EXPLANATION
----------------------------------------------------------------------
  (?:                      group, but do not capture:
----------------------------------------------------------------------
    \s+                      whitespace (\n, \r, \t, \f, and " ") (1
                             or more times (matching the most amount
                             possible))
----------------------------------------------------------------------
   |                        OR
----------------------------------------------------------------------
    \A                       the beginning of the string
----------------------------------------------------------------------
  )                        end of grouping
----------------------------------------------------------------------
  [#'"[({]?                any character of: '#', ''', '"', '[', '(',
                           '{' (optional (matching the most amount
                           possible))
----------------------------------------------------------------------
  (?!                      look ahead to see if there is not:
----------------------------------------------------------------------
    (?:                      group, but do not capture (3 times):
----------------------------------------------------------------------
      [a-z]{2}                 any character of: 'a' to 'z' (2 times)
----------------------------------------------------------------------
      \s+                      whitespace (\n, \r, \t, \f, and " ")
                               (1 or more times (matching the most
                               amount possible))
----------------------------------------------------------------------
    ){3}                     end of grouping
----------------------------------------------------------------------
  )                        end of look-ahead
----------------------------------------------------------------------
  (?:                      group, but do not capture:
----------------------------------------------------------------------
    [a-zA-Z'-]{2,}           any character of: 'a' to 'z', 'A' to
                             'Z', ''', '-' (at least 2 times
                             (matching the most amount possible))
----------------------------------------------------------------------
   |                        OR
----------------------------------------------------------------------
    [ia]                     any character of: 'i', 'a'
----------------------------------------------------------------------
   |                        OR
----------------------------------------------------------------------
    i                        'i'
----------------------------------------------------------------------
    [nst]                    any character of: 'n', 's', 't'
----------------------------------------------------------------------
   |                        OR
----------------------------------------------------------------------
    o                        'o'
----------------------------------------------------------------------
    [fnr]                    any character of: 'f', 'n', 'r'
----------------------------------------------------------------------
  )                        end of grouping
----------------------------------------------------------------------
  [?!.,;:'")}\]]?          any character of: '?', '!', '.', ',', ';',
                           ':', ''', '"', ')', '}', '\]' (optional
                           (matching the most amount possible))
----------------------------------------------------------------------
  (?=                      look ahead to see if there is:
----------------------------------------------------------------------
    (?:                      group, but do not capture:
----------------------------------------------------------------------
      \s                       whitespace (\n, \r, \t, \f, and " ")
----------------------------------------------------------------------
     |                        OR
----------------------------------------------------------------------
      \Z                       before an optional \n, and the end of
                               the string
----------------------------------------------------------------------
    )                        end of grouping
----------------------------------------------------------------------
  )                        end of look-ahead
----------------------------------------------------------------------
 |                        OR
----------------------------------------------------------------------
  (                        group and capture to \1:
----------------------------------------------------------------------
    (?:                      group, but do not capture (3 times):
----------------------------------------------------------------------
      [a-z]{2}                 any character of: 'a' to 'z' (2 times)
----------------------------------------------------------------------
      \s+                      whitespace (\n, \r, \t, \f, and " ")
                               (1 or more times (matching the most
                               amount possible))
----------------------------------------------------------------------
    ){3}                     end of grouping
----------------------------------------------------------------------
   |                        OR
----------------------------------------------------------------------
    .*?                      any character except \n (0 or more times
                             (matching the least amount possible))
----------------------------------------------------------------------
    \b                       the boundary between a word char (\w)
                             and something that is not a word char
----------------------------------------------------------------------
  )                        end of \1
----------------------------------------------------------------------
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