use warnings;
use strict;

my %data;
while (<DATA>) {
    chomp;
    my ($id, $sum, $reason) = split /\|/;
    $data{$id}{sum} += $sum;
    $data{$id}{reason} = $reason;
}

use Data::Dumper; $Data::Dumper::Sortkeys=1; print Dumper(\%data);

__DATA__
USERID1|2215|Jones,Tom|
USERID1|1000|Jones, Tom|
USERID3|1495|Dole, Bob|
USERID2|2500|Francis, Pope|
USERID2|1500|Francis, Pope|
[download]

• perldsc