My guess to your meaning would be: 

print $2 while 'abccabbcabc' =~ m[(c).*?(\1)]g;;
c
c

[download]

As for your purpose, that's beyond me. Care to enlighten us?

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
RIP an inspiration; A true Folk's Guy

In reply to Re: Regex to only show 2nd character of the same character in a string by BrowserUk
in thread Regex to only show 2nd character of the same character in a string by wtritchie

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