#!/usr/bin/perl -w

#######################################################
# lect08_sprintf
#
# quickie example of sprintf
#
# modified by Sharon Tuttle from "Learning Perl",
#    by Schartz and Phoenix
#
# last modified: 10-11-04
#######################################################

#------------------------------------------------
# print a large monetary number with 2 fractional
#    places, and commas if >=1000
#------------------------------------------------

sub big_money
{
    # expecting only 1 parameter, ignoring the rest.
    #    (and immediately, firstly, formatted to
    #    1 fractional places)

    my $number = sprintf "%.2f", shift @_;

    # do-nothing loop: loop through, adding as many
    #    commas as needed;

    # from BEGINNING of number, 
    #    match 0 or 1 negative signs, then 1 or more digits
    #       (memory #1)
    #    and then exactly 3 digits (memory #2) ---
    # if you CAN,
    #    then substitute memory #1, comma, memory #2

    while ($number =~ s/^(-?\d+)(\d\d\d)/$1,$2/)
    {
        1;   # traditional Perl placeholder...!
    }

    # put the dollar sign in the right place

    $number =~ s/^(-?)/$1\$/;

    return $number;
}

# "little" number example

my $pretty_amt_owed = sprintf "\$%.2f", 2.49997;

print "$pretty_amt_owed\n";

# "big" number example

print &big_money(999.8555) . "\n";
print &big_money(1000) . "\n";
print &big_money(-1000.333) . "\n";
print &big_money(5764333.3) . "\n";

# oh, print 'em even prettier!

print "\nPRETTIER...\n";
print "----------------\n";

my @money_list = (999.8555, 1000, -1000.333, 5764333.3);
my $amount;

foreach (@money_list)
{
    $amount = $_;

    printf "%16s\n", &big_money($amount);
}
print "\n";

# end of lect08_sprintf