Regex teaser

Simon Cozens simon at
Wed Dec 4 01:02:10 GMT 2013

On 04/12/2013 08:54, Paul Makepeace wrote:
> $ perl -le '($a = "aabbb") =~ s/b*$/c/g; print $a'

Why... oh. That's clever. Yes.

For those like me who are slow and can't immediately see why that does what it 
does, here are some hints:

What does perl -le '($a = "aabbb") =~ s/b+$/c/g; print $a' do?

What would s/b*$/c/g do if there aren't any "b"s at the end of the matched string?

How many "b"s are matched to produce the first "c"? How many "b"s are matched 
produce the second "c"?

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