$*      Set to 1 to do multiline matching within a string, 0
             to tell perl that it can assume that strings contain
             a single line, for the purpose of optimizing pattern
             matches.  Pattern matches on strings containing mul-
             tiple newlines can produce confusing results when $*
             is  0.  Default is 0.  (Mnemonic: * matches multiple
             things.)  Note that this  variable  only  influences
             the  interpretation  of  ^ and $.  A literal newline
             can be searched for even when $* == 0.