use strict;
use warnings;

while ( <DATA> ) {
  /(^foo.*bar$)(?{print "BOTH FOUND: $_"}) |
   (^foo)      (?{print "FOO FOUND: $_"})  |
   (bar$)      (?{print "BAR FOUND: $_"})/x
}

__DATA__
foo baz
foo bar
bar
fu bar
fuz
foo on you bar