#!perl -p use List::Util 'shuffle'; $_=~s{(?<=\b\w)(\w+)(?=\w\b)}{join'',shuffle split//,$1}xeg; #### perl -MList::Util=shuffle -pe '$_=~s{(?<=\b\w)(\w+)(?=\w\b)}{join"",shuffle split//,$1}xeg;'