How would I write a RegEx to:
Find a match where the first instance of a > character is before the first instance of a < character.
(I am looking for bad HTML where the closing > initially in a line has no opening <.)
views:
48answers:
3
A:
^[^<>]*>
if you need the corresponding < as well,
^[^<>]*>[^<]*<
If there is a possibility of tags before the first >,
^[^<>]*(?:<[^<>]+>[^<>]*)*>
Note that it can give false positives, e.g.
<!-- > -->
is a valid HTML, but the RegEx will complain.
KennyTM
2010-08-17 14:48:21
It seems as if this won't catch this a line with: <tag1> badtag2>
Mark Wilkins
2010-08-17 15:22:12
+1
A:
Would this work?
string =~ /^[^<]*>/
This should start at the beginning of the line, look for all characters that aren't an open '<' and then match if it finds a close '>' tag.
spig
2010-08-17 14:51:29
I think that's a problem with the question. This will do what he asked it to do. To get the previous lines opens up the can-of-worms with using a regular expression to check a non-regular language.
spig
2010-08-17 15:06:25
In perl/ruby and other languages you can use the "m" modifier which will treat the entire string as one line regardless of line breaks. I re-read his question and he doesn't necessarily specify that it would be all on one line. `string =~ /^[^<]*>/m`
spig
2010-08-17 15:32:42
+1
A:
It's a pretty bad idea to try to parse html with regex, or even try to detect broken html with a regex.
What happens when there is a linebreak so that the > character is the first character on the line for example (valid html).
You might get some mileage from reading the answers to this question also: http://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags
Alexander Kjäll
2010-08-17 14:53:14