正则表达式查找美元金额但不匹配IP地址

Question

I have sections of text that may contain both dollar amounts, that may or may not be prepended with a dollar sign, and IP addresses. I need a regular expression that will identify the dollar amounts but not match portions of the IP addresses.

For example if the text is:

12.34 56.78.90.12 34.56

My starting attempt was:

([1-9]\d*\.\d{2})

This is what I want to match, but it matches parts of the IP addresses. I then tried:

[^\.]([1-9]\d*\.\d{2})[^\.]

But this was worse on almost all cases.

The regular expression needs to match "12.34" and "34.56", but not "56.78" or "90.12". Any help would be appreciated.

Answer 1

Use lookaround assertions and word boundary anchors to make sure that there are no dots around your match:

(?<!\.)\b[1-9]\d*\.\d{2}\b(?!\.)

Test it live on regex101.com.