C:\>more foo bar baz.pl
Cannot access file C:\foo

C:\>more "foo bar baz.pl"

print "foo bar baz.pl says hi";

C:\>perl 
my @args = ( $^X, 'foo bar baz.pl' );
warn "  while going through the shell ret = ".system "@args";
warn "  while avoding the shell ret = ".system {$args[0]} @args;

__END__
Can't open perl script "foo": No such file or directory
  while going through the shell ret = 512 at - line 2.
foo bar baz.pl says hi  while avoding the shell ret = 0 at - line 3.