正则表达式并忽略空格 [英] Regex and ignore whitespace

问题描述

我有以下正则表达式，用于在文件字符串搜索中匹配各种信用卡号.但是，如果要匹配的模式前后有空格，则匹配将失败.

I have the following regex that I am using to match on various credit card numbers within a string search of files. However, if there is a space before or after the pattern to match, then the match will fail.

$CC_Regex = "^(\d{4}-){3}\d{4}$|^(\d{4} ){3}\d{4}$|^\d{16}$"

例如，它会匹配前三名，但不会匹配后三名.

For example, it will match the top three, but will not match the bottom three.

1111-2323-2312-3434
1234343425262837
1111 2323 2312 3434

1111-2323-2312-3434 
 1234343425262837
 1111 2323 2312 3434 

在后三个中，第一个末尾有一个空格，第二个前面有一个空格，第三个前后有一个空格.

Out of the bottom three, the first one has a space at the end of it, the second one has a space before it, and the third one has a space before and after it.

预先感谢您的帮助.

推荐答案

扩充正则表达式以处理前端和末尾的空格很容易:

It would be easy enough to augment the regex to handle whitespace at the front and end:

^\s*(?:(\d{4}-){3}\d{4}|(\d{4} ){3}\d{4}|\d{16})\s*$

但取字符串似乎更谨慎，删除除数字以外的所有内容，然后检查它是否为 16 位数字:

but it seems more prudent to take the string, remove everything except digits, and then check if it's a 16-digit number:

$result = $subject -creplace '[^0-9]+', ''
$found = $result -cmatch '^[0-9]{16}$'

毕竟，谁知道人们可能对格式有什么想法 - 组之间的几个空格，空格和破折号的混合等等...

After all, who knows what ideas people might have for formatting - several spaces between groups, mixes of spaces and dashes etc...

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