use strict;
  my($a,$b,$c,$d);
my $str="a b c d";
if($str=~m/(\S)\s(\S)\s(\S)\s(\S)/)
 {
($a,$b,$c,$d)=map {eval(\$$_)} (1..4);}
print $a,"\n",$b,"\n",$c,"\n",$d;