Regex Group in Perl: how to capture elements into array from regex group that matches unknown number of/multiple/variable occurrences from a string?

Question

In Perl, how can I use one regex grouping to capture more than one occurrence that matches it, into several array elements?

For example, for a string:

Answer 1

I've recently had to parse x509 certificates "Subject" lines. They had similar form to the one you have provided:

echo 'Subject: C=HU, L=Budapest, O=Microsec Ltd., CN=Microsec e-Szigno Root CA 2009/emailAddress=info@e-szigno.hu' | \
  perl -wne 'my @a = m/(\w+\=.+?)(?=(?:, \w+\=|$))/g; print "$_\n" foreach @a;'

C=HU
L=Budapest
O=Microsec Ltd.
CN=Microsec e-Szigno Root CA 2009/emailAddress=info@e-szigno.hu

Short description of the regex:

(\w+\=.+?) - capture words followed by '=' and any subsequent symbols in non greedy mode
(?=(?:, \w+\=|$)) - which are followed by either another , KEY=val or end of line.

The interesting part of the regex used are:

• .+? - Non greedy mode
• (?:pattern) - Non capturing mode
• (?=pattern) zero-width positive look-ahead assertion