$ echo bbbaaabbb | sed -e 's/\(b*\)/(\1)/g'
(bbb)()a()a()a(bbb)
 $ 

##</code><code>##

 $ echo bbbaaabbb | sed -e 's/\(b*\)/(\1)/g'
(bbb)a()a()a(bbb)
 $ 

##</code><code>##

 $ echo bbbaaabbb | perl -pe 's/(b*)/(\1)/g'
(bbb)()a()a()a(bbb)()
() $ echo bbbaaabbb | perl -lpe 's/(b*)/(\1)/g' >
(bbb)()a()a()a(bbb)()
 $ 

##</code><code>##

[bbaabb]
(bb)
(b)
()
 (b)
 ()
 .()
 ..()
 ...(bb)
 ...(b)
 ...()
 ....(b)
 ....()
 .....()
[bbaabb]

##</code><code>##

[bbaabb]
()
(b)
(bb)
 ()
 (b)
 .()
 ..()
 ...()
 ...(b)
 ...(bb)
 ....()
 ....(b)
 .....()
[bbaabb]