Thomas H. George wrote:
The solution given on page 225 fails if warn or use strict are turned
on. The error is the use of an undefined variable in the sort of
destinations.
I decided to ignore this and move on to Chapter 6. There using perldebug
and -d:ptkdb I have studied the problem again. The hashes all look ok
but something related to the $all variable introduces undefined
variables with each iteration of the sort routine.
Here is the solution as I have copied it:
#!/usr/bin/perl -w
#
use strict;
use diagnostics;
my %total_bytes;
my $all = "All Machines";
while ( <> ) {
next if /^#/;
my ($source, $destination, $bytes) = split;
$total_bytes{$source}{$destination} += $bytes;
$total_bytes{$source}{$all} += $bytes;
}
my @sources =
sort { $total_bytes{$b}{$all} <=> $total_bytes{$a}{$all} }
keys %total_bytes;
for my $source (@sources) {
my @destinations =
sort {$total_bytes{$source}{$b} <=> $total_bytes{$source}{a} }
^^^
That should be:
sort {$total_bytes{$source}{$b} <=> $total_bytes{$source}{$a} }
keys %{ $total_bytes{$source} };
print "$source: $total_bytes{$source}{$all} total bytes send\n";
for my $destination (@destinations) {
next if $destination eq $all;
print " $source => $destination:",
" $total_bytes{$source}{$destination} bytes\n";
}
print "\n";
}
For the present I have turned off warn and use strict in order to
proceed with the solution of Chapter 6, Problem 1 using this program as
the starting point.
John
--
Those people who think they know everything are a great
annoyance to those of us who do. -- Isaac Asimov
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