CODEWITHSUNDEEP
javaregex
user2150250
user2150250

Reputation: 5167

Capturing Headers in a List Using Regex

I have the following string I am trying to capture from (let's call it output):

ltm pool TEST_POOL { 
    Some strings
    above headers
    records { 
        baz:1 {
            ANY STRING
            HERE 
        } 
        foobar:23 { 
            ALSO ANY
            STRING HERE 
        }
    }
    members {
        qux:45 {
            ALSO ANY
            STRINGS HERE
        }
        bash:2 {
            AND ANY
            STRING HERE
        }
        topaz:789 {
            AND ANY
            STRING HERE
        }        
    }
    Some strings
    below headers
}

Consider each line of output to be separated by a typical line break. For the sake of this question, let's refer to records and members as "titles" and baz, foobar, qux, bash, and topaz as "headers". I am trying to formulate a regex in Java that will capture all headers between the brackets of a given title in a find loop. For example, given we want to find all headers of title members with this code:

        String regex = TODO; // members\\s\\{ contained in regex
        final Pattern pattern = Pattern.compile(regex);
        Matcher matcher = pattern.matcher(output);
        while (matcher.find()) {
            System.out.println(matcher.group(1));
        }

The output should be ...

qux
bash
topaz

And should exclude baz and foobar because they are contained within the brackets of a different "title". There can be any number of titles and any number of headers. Some help in formulating a regex to solve this problem would be much appreciated.

Upvotes: 0

Views: 95

Answers (1)

anubhava
anubhava

Reputation: 785856

You can use this regex using \G that asserts position at the end of the previous match or the start of the string for the first match:

(?:\bmembers\s*\{|(?<!^)\G[^{]+\{[^}]+\})\s*?\n\s*([^:{}]+)(?=:\d)

OR:

(?:\brecords\s*\{|(?<!^)\G[^{]+\{[^}]+\})\s*?\n\s*([^:{}]+)(?=:\d)

This is assuming there are no nested and escaped { and }.

RegEx Demo

Upvotes: 1

Related Questions