Sum values in second column in a text file - perl

Question

I have a text file with the following format:
1 4730 1031782 init
4 0 6 events
2190 450 0 top
21413 5928 1 sshd
22355 1970 2009 find
I need to sum the second column of data and return that value to the user.
My current attempt reads the data from the text file like so:
sub read_file{
my $data_failed = 1;
my $file = 'task_file';
if (-z $file){print "No tasks found\n";}
if(open (INFILE, "task_file" || die "$!\n")){
my #COLUMNS = qw( memory cpu program );
my %sort_strings = ( program => sub { $a cmp $b } );
my (%process_details, %sort);
while (<INFILE>) {
$data_failed = 0;
my ($process_id, $memory_size, $cpu_time, $program_name) = split;
$process_details{$process_id} = { memory => $memory_size,
cpu => $cpu_time,
program => $program_name };
undef $sort{memory}{$memory_size}{$process_id};
undef $sort{cpu}{$cpu_time}{$process_id};
undef $sort{program}{$program_name}{$process_id};
}
for my $column ($COLUMNS[2]) {
my $cmp = $sort_strings{$column} || sub { $a <=> $b };
for my $value (sort $cmp keys %{ $sort{$column} }
) {
my #pids = keys %{ $sort{$column}{$value} };
say join ' ', $_, #{ $process_details{$_} }{#COLUMNS}
for #pids;
}
}
if($total_memory_size == 1){
sum_memory_size();
}
} else { print "No tasks found"}
}
And my attempt to sum the values:
sub sum_memory_size{
my #do_sum = qw(memory_size);
my $column;
my $value;
for $column (keys %{ $sort{$column}{$value} }) {
my $found;
my $sum = 0;
for $value (#do_sum) {
next unless exists $sort{$column}{$value};
$sum += $hash{$column}{$value};
delete $hash{$column}{$value};
$found = 1;
}
$sort{$column}{somename} = $sum if $found;
}
print $sum;
}

Answer 1

Use sum form List::Util:
use List::Util qw{ sum };
# ...
my $memory_sum = sum(map $_->{memory}, values %process_details);

Answer 2

The question describes a simple task, which appears to be part of a larger problem. One answer to the simple task is:
perl -ne '#fields=split; $sum+=$fields[1]; END { print "$sum\n" }' foo.txt
For each line (-ne), split it and add the second value ($fields[1]) to a running $sum. Then, after all lines have been processed (END), print the sum. I get 13078 from the program, which is also what I get from a calculator on the input above :) (4730 + 0 + 450 + 5928 + 1970).