my %transactions;

...

my @fields = split(/\s+/);

my %rec;
$rec{$_} = shift(@fields) for ( qw(date time tid status trname tramount) );

if ( $rec{status} eq "start" ) {
    $transactions{$rec{tid}} = \%rec;
} elsif ( $rec{status} eq "stop" ) {
    if ( exists($transactions{$rec{tid}}) ) {
        # report transaction time and amount
    } else {
        warn "ERROR: stop without start: $_";
    }
} else {
    warn "ERROR: unrecognized status: $_";
}