regex matching an open and close tag and a certain text patterns inside that tag [duplicate]

This question already has answers here: What to do Regular expression pattern doesn't match anywhere in string? (8 answers) Closed 7 years ago.

Here is a sample custom tag i have from a sitemap.xml

<url>
  <loc>http://sitename.com/programming/php/?C=D;O=A</loc>
  <changefreq>weekly</changefreq>
  <priority>0.64</priority>
</url>

There are many entries like this and if you see loc tag it has c=d;0=a at the end. I want to remove all entries 开发者_StackOverflow社区starting with <url> ending with </url> which contains C=D;0=A or similar patterns like that.

The following expression matched the whole of the above specified tag

<url>(.|\r\n)*?<\/url>

but I want to match like what i had specified in the above statement.

How do we form regex to match such conditions(patterns) ?

---

Try this:

/<url>(?:(?!<\/url>).)*C=D;O=A.*?<\/url>/m

The negative lookahead guaranties that you do not match multiple nodes.

See here: rubular

---

It is not a good idea to use regex for XML. Depending on the language you should use some XML reader, extract the <url> node and then use regex to match the content of the node. One useful language for querying XML data, which is supported by many XML libraries is XPath.

---

If you absolutely have to use regex, this one:

<([a-z][a-z0-9]*)\b[^>]*>(.*?)(C=D;O=A){1}(.*?)</\1>

will get you the line:

http://sitename.com/programming/php/?C=D;O=A

I would then traverse up to the parent tag and do whatever I wanted with it.