#!/usr/bin/perl -w
use strict;

$_ = "abc def\n";
/^(\w+)\s+(\w+)$/;
print "<$1><$2>\n";

$_ = "xyz 6-7\n";
/^(\w+)\s+(\w+)$/;
print "<$1><$2>\n";

$_ = "123 456\n";
/^(\w+)\s+(\w+)$/;
print "<$1><$2>\n";

##</code><code>##

<abc><def>
<abc><def>
<123><456>

##</code><code>##

while (<DATA>) {
  if (/^(\w+)\s+(\w+)$/) {
    print "<$1><$2>\n";
  } else  {
    print "Line $. didn't match\n";
  }
}