I'm not sure you need the complication of oha's method here as it depends on the fact that the left side of the alternation will still match once you have done the first substitution whereas in your problem it won't. Using just a capture group seems to work.

$ perl -E '
> $_ = q{Bla class="x1" class="x2" class="x3" Blabla};
> say;
> s{" class="([^"]+)}{ $1}g;
> say;'
Bla class="x1" class="x2" class="x3" Blabla
Bla class="x1 x2 x3" Blabla

[download]

Attacking the problem from (literally) a different direction would be another way of achieving the same result without a capture group.

$ perl -E '
> $_ = q{Bla class="x1" class="x2" class="x3" Blabla};
> say;
> $r = reverse $_;
> $r =~ s{"=ssalc "}{ }g;
> $_ = reverse $r;
> say;'
Bla class="x1" class="x2" class="x3" Blabla
Bla class="x1 x2 x3" Blabla
$

[download]

I hope this is helpful.

Cheers,

JohnGG

Update: I forgot to mention, double-quotes are not regex metacharacters so they don't need to be escaped.

In reply to Re^4: Can you assign to pos() in a s/foo/bar/g by johngg
in thread Can you assign to pos() in a s/foo/bar/g by johngg

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