Define given number of tabs in Regex lookbehind (pcregrep)

Question

I use pcregrep to find patterns over multiple-lines in html code.

I try to match something that looks similar to this:

<some-html-stuff>
                    sometext<more-html-stuff>

The space between sometext and the beginning of the line equals exactly six tabs. Since the expression \s matches tabs, linebreaks and whitspaces I thought that

pcregrep -M -o -H "(?<=some-html-stuff\>[\s]{7})[A-Za-z0-9]*" /path/file.html

would do the job for me. but it does not (I added an additional one for the break). I actually tried this with several variations of the number but neither works.

What did I oversee?

edit:

the match should be sometext without any whitespaces before.

What do you want to match? – Avinash Raj Aug 03 '14 at 09:57 — Avinash Raj, Aug 03 '14 at 09:57
you mean this http://regex101.com/r/vC2yW4/4 – Avinash Raj Aug 03 '14 at 10:05 — Avinash Raj, Aug 03 '14 at 10:05

score 1 · Answer 1 · edited Jun 20 '20 at 09:12

1

This regex will work for you:

(?<=some-html-stuff\>\n\s{7})([A-Za-z0-9]+)

You need to insert \n before using \s{7} to match 7 tabs OR else use \s{8} like this:

(?<=some-html-stuff\>)\s{8}([A-Za-z0-9]+)

since \s also matches \n.

RegEx Demo

edited Jun 20 '20 at 09:12

Community

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answered Aug 03 '14 at 10:01

anubhava

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almost works. but i don't want the whitespaces not to be part of the string that is returned. thats why they need to be included in the lookbehind... – joaoal Aug 03 '14 at 10:14
You can use: `(?<=some-html-stuff\>\n\s{7})([A-Za-z0-9]+)` for that. – anubhava Aug 03 '14 at 10:15
it does not work. my complete code is `(?<=\"some-htmlstuff\"\>\n\s{6})([A-Za-z0-9\s\.]+)"` with only 6 in the brackts since there are only six tabs... I have tried this solution too but it does not work...does it work for you? – joaoal Aug 03 '14 at 10:40
Did you check the demo link? If it doesn't work for me I don't post an answer here. – anubhava Aug 03 '14 at 10:42
i did. this demo site is awesome! i will have to fix it inside my code but now I know that in theory it works.thanks! – joaoal Aug 03 '14 at 10:46
Yes this is indeed an awesome online regex tester. Glad it worked out for you. – anubhava Aug 03 '14 at 10:48

Avinash Raj · Accepted Answer · 2014-08-03T10:30:08.603

1

You could use \K instead of lookbehind,

pcregrep -M -o -H "<some-html-stuff\>\s*\K[A-Za-z0-9]+" /path/file.html

DEMO

OR

pcregrep -M -o -H "some-html-stuff\>\n\t{7}\K[A-Za-z0-9]+" /path/file.html

DEMO

edited Aug 03 '14 at 10:30

answered Aug 03 '14 at 10:23

Avinash Raj

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`\K` ignores the previously matched characters. – Avinash Raj Aug 03 '14 at 11:29

Define given number of tabs in Regex lookbehind (pcregrep)

2 Answers2

RegEx Demo