print "$_ ", /(.*)(?{$countSpaces->()})/ ? "has 1 or no spaces\n" : "has more than one space\n";

##</code><code>##

this line has more than one space
 has more than one space
     that_is_5_spaces
 has more than one space
This isonespaceonly
 has more than one space
therearenospaceshere
 has 1 or no spaces