in reply to Work-around for variable length look-behind?

~/$ perl -e '$string=" bbaaccbab sdcbalsbadcnw";while($string=~s/(\S+\
+s.+?)b(?=a)/$1B/g){}print "$string\n";'
 bbaaccbab sdcBalsBadcnw

[download]
print "Good ",qw(night morning afternoon evening)[(localtime)[2]/6]," fellow monks."

In Section Seekers of Perl Wisdom