Find a text, but not inside another one

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August 7th, 2012, 10:07 AM

Torsten79

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Find a text, but not inside another one

Hi all,

I'm searching for a regex which will find a text, but this text should not be inside another text (comment).

e.g. searching string "<data>" inside the following comment sign (starting "") should not be found

Code:

<!---
this is a comment about my <data>.
but the <data> should not be found 
--->

but on the other hand in this case are two possible hits

Code:

<data> hits first here.
<!---
this is a comment about my <data>.
but the <data> should not be found 
--->
And here comes hit no. 2 for <data>

Thanks in advance for your helps.

August 7th, 2012, 11:35 AM

requinix

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If that's XML then you should be using XML methods, not regular expressions. Exactly how depends on what language(s) you're using.

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August 8th, 2012, 01:55 AM

Torsten79

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Hi requinix,

Thanks for your reply.

But its no XML, its a Coldfusion source file - so you should expect it as a normal string. I will also not only search for certain tags, but searching for normal text too.

With "()" I can find any comment. My question is now how to invert this regex, so it would find any text outside of any comment and at the next step this regex should also find the text I'm searching for ("<data>" in the example above).

August 8th, 2012, 02:00 AM

requinix

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Then it's HTML (or looks like it)? DOM is the answer.

I'm trying to steer you away from regular expressions because it's a nightmare to write something that respects HTML or XML grammar. Simply ignoring comments is not simple.

August 8th, 2012, 02:45 AM

Jacques1

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Hi,

You might look for both comments and the actual search pattern and then skip the comments afterwards.

i. e.

Code:

/<!---.*?--->|YOURPATTERN/

However, this isn't really a good solution. I fully agree with requinix that you should use a parser rather than fumble with regular expressions.

August 9th, 2012, 02:52 AM

Torsten79

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Well, thanks for your efforts. So it seems that there is no way to skip text within a search.

I solved it now with two steps as suggested by Jaques1. First I delete all unwanted "" from text. In second step I'm searching for the "<data>".

DOM and other possibilities are too complex (and therefore time consumpting) for only looking if "<data>" is inside a text or not.

August 9th, 2012, 05:14 PM

requinix

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Quote:

Originally Posted by Torsten79

DOM and other possibilities are too complex

Huh. Then you must be using some language that doesn't feature any kind of DOM support whatsoever. Congratulations on being an exception to the rule.

August 11th, 2012, 05:32 PM

spacebar208

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If I understand you correctly, You can do it with sed:

Code:

$ cat t
<data> hits first here.
<!---
this is a comment about my <data>.
but the <data> should not be found
--->
And here comes hit no. 2 for <data>

Print lines with search data ignoring comment blocks:

Code:

$ sed -n -e '/^<\!---/,/^--->/d' -e '/<data>/p' t
<data> hits first here.
And here comes hit no. 2 for <data>

Print lines with search data ignoring comment blocks and their line numbers:

Code:

$ sed -n -e '/^<\!---/,/^--->/d' -e '/<data>/=;p' t
1
<data> hits first here.
6
And here comes hit no. 2 for <data>

And a couple of examples of printing line number on same line with text found:

Code:

$ sed = t | sed 'N;s/\n/\t/' | sed -n -e '/^[0-9]\{1,\}\t<\!---/,/^[0-9]\{1,\}\t--->/d' -e '/<data>/p'
1       <data> hits first here.
6       And here comes hit no. 2 for <data>

$ sed = t | sed 'N;s/\n/ - /' | sed -n -e '/^[0-9]\{1,\} - <\!---/,/^[0-9]\{1,\} - --->/d' -e '/<data>/p'
1 - <data> hits first here.
6 - And here comes hit no. 2 for <data>

Find a text, but not inside another one

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