Philippe 'BooK' Bruhat ([EMAIL PROTECTED]) wrote:
> What you want is:
>
> s/(?!^).(?!$)/$&$&/g
>
> Now, can we shorten it?
>
> s/\B.(?=\B)/$&$&/g
Except that that tickles the bug discussed elsewhere in this thread,
and is hence no use.
$ echo 1234 | perl5.6.1 -lpe 's/\B.(?=\B)/$&$&/g'
12234
> Anything better?
Yep :-)
s/(?=.(.).)/$+/g
Produces all but the penultimate pair in reverse order, which is of
course OK, because the function is symmetrical. I didn't end up using
it though, and noone else did either, it seems.
