Hi, Monks!

I have a regex problem today that I thought would be a quickie. I have a file with lines containing two strings separated by a whitespace. I want to make a specific global replacement, say every 'b' in front of an 'a' shall beome 'B', ONLY in the second string.
So
 bbaaccbab sdcbalsbadcnw
should become
bbaaccbab sdcBalsBadcnw

[download]
Clearly s/b(?=a)/B/g won't work because it may also effect a replacement in the first string in the line.

Of course, I could capture the second string in a preceeding match and then operate on it. What I want to achieve, however, is to express this in a single regex.

With variable length look-behind unsupported by the Perl version I use (5.8 something) I am at a loss.

Can you please help?

Cheers and thanks in advance for your advise -

Pat

In reply to Work-around for variable length look-behind? by pat_mc

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