my $str = `type unsort.txt`;

$str = join("\n", 
        map($_->[0],
            sort( {$a->[1] <=> $b->[1] }#for alpha order change <=> to cmp
              map( [$_, (split('\|', $_))[1] ],#change this number to control which field to use, 0 for 1st field 
                   split(/\n/, $str)
                 )
             )
           )
           );

print $str;