knoppix@Microknoppix:~$ perl -E '
> $_ = q{bbaaccbab sdcbalsbadcbnw};
> s/(\s\w+)ba/\1Ba/g;
> say;'
bbaaccbab sdcbalsBadcbnw
knoppix@Microknoppix:~$ 

##</code><code>##

knoppix@Microknoppix:~$ perl -E '
> $_ = q{bbaaccbab sdcbalsbadcbnw};
> s/(\s\w+?)ba/\1Ba/g;
> say;'
bbaaccbab sdcBalsbadcbnw
knoppix@Microknoppix:~$ 

##</code><code>##

knoppix@Microknoppix:~$ perl -E '
> $_ = q{bbaaccbab sdcbalsbadcbnw};
> s/(\s?\w+?)ba/\1Ba/g;
> say;'
bBaaccBab sdcBalsBadcbnw
knoppix@Microknoppix:~$