Hi out there,
who of you can solve the following problem?

Our goal is to read from a non-formatted text file and print it out with all occurences of exactly two same characters in consecutive order enclosed in parentheses. Condition is to do it in an one-line perl script, if possible using regex (and not split because thatīs too easy).

If our input file would be:

sssshjfdhgriuu
xxddvvggggaaaiii
ougur9s oknddpp
hgorsagnnnnccc
nkjl(())uh

... the output should be:

sssshjfdhgri(uu)
(xx)(dd)(vv)ggggaaaiii
ougur9s( )okn(dd)(pp)
hgorsagnnnnccc
nkjl((()()))uh

One of the non-working (and more than one line) attempts:
while (<>) {
  s/(.)((?!\1).)\2(?!\2)/$1\($2$2\)$3/g;
  s/^(.)\1(?!\1)/\($1$1\)$2/;
  print;
}

[download]
Looking forward to your answers,
r

In reply to How to do it in one line? by r

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