#!/usr/bin/perl -w

#######################################################
# lect08_dbm3
#
# now display the contents of the score_db DBM file(s)
#    highest-score first, in ASCIIbetical order 
#    of key for those with the same score.
#
# modified by Sharon Tuttle from "Learning Perl",
#    by Schartz and Phoenix
#
# last modified: 10-12-04
#######################################################

# open an existing OR create a new DBM file, accessible
#    via a DBM hash
# (note --- same DBM file -- but I can call the DBM hash
#    variable different names in different scripts, if
#    I want to...)

dbmopen(%SCORES, "score_db", 0644)
    or die "Cannot create score_db: $!";

# let's show the contents highest-score to lowest,
#    with ties shown in ASCIIbetical order by key

#-----------------------------------------------------
# SORT SUBROUTINE,
#    so, since it involves a particular hash, it IS
#    using a GLOBAL variable, and we've placed it
#    AFTER we know that the hash exists
#---------------------------------------------------

sub score_sort
{
    $SCORES{ $b } <=> $SCORES{ $a }
        or
    $a cmp $b
}

# HMMM --- SHOULD use while and each to more EFFICENTLY
#    access hash (in terms of memory efficiency) ---
#    BUT I don't see how I would sort the values, then...?

print "\n";
foreach my $scorer (sort score_sort keys %SCORES)
{
    printf "%-10s %5d\n", $scorer, $SCORES{ $scorer };
}

print "\n";

# end of lect08_dbm3