$File = "input.txt";
open(FH,$File);

while ( <FH>) {
    ## Chomp the read line. i.e removing \n available at the end
    chomp;
    ## taking time, transaction id, status,  transaction name and amount.
    if ( $_ =~ /([0-9]+\:[0-9]+\:[0-9]+) ([0-9]+) (\w+) (\w+) (\w+)/ ){
        $time = $1;
        $tid = $2;
        $status = $3;
        $trname = $4;
        $tramount = $5;

        $hash{$2}->[0] = $status;
        $hash{$2}->[1] = $time;
        $hash{$2}->[2] = $trname;
        $hash{$2}->[3] = $tramount;
    }
    ##  If the status is stop..
    elsif ( $_ =~ /([0-9]+\:[0-9]+\:[0-9]+) ([0-9]+) (\w)/ ) {
        $status = $3;
        $hash{$2}->[0] = $status;
        $difftime = find_diff($hash{$2}->[1],$1);
        $hash{$2}->[1] = $difftime;
        print "Transaction id $2 name ".$hash{$2}->[2]." Amount ". $hash{$2}->[3]." Duration ".$hash{$2}->[1]."\n";
    # If the transaction is stopped initialising the values.
        $hash{$2}->[0] = 0;
        $hash{$2}->[1] = 0;
        $hash{$2}->[2] = 0;
        $hash{$2}->[3] = 0;
    }
}

print "============================================\n";
## to print the transaction started but not yet stopped
foreach $id ( keys %hash ) {
        if ( $hash{$id}->[0] =~ /start/i ) {
            print "Transaction with id $id is started but not yet stopped\n";
        }
}

sub find_diff {
    ## Get the start time and end time and store that in a variable.
    my ( $begin, $end ) = @_;

    # Declaration of local variables.
    my ( $hour , $min, $sec , $hour1, $min1, $sec1, $tdiff);

    # split the start time which has a : as a seperator, and store hour, min
    # sec.
    ($hour, $min, $sec ) = split(/\:/,$begin);
    # Convert the start time into seconds.
    $stime = ( $hour *3600 ) + ($min *60) + $sec;
    # split the end time which has a : as a seperator, and store hour, min
    # sec.
    ($hour1, $min1, $sec1 ) = split(/\:/,$end);
    # Convert the end time into seconds.
    $etime = ( $hour1 *3600 ) + ($min1 *60) + $sec1;

    # subtract the end time from start time.
    $diff = $etime - $stime;
    # conversion of seconds to hour, min and sec.
    $hour = int($diff/3600);
    $min1 = int($diff%3600);
    $min = int($min1/60);
    $sec = int($min1%60);# Form the hour min sec like hh:mm:ss
    $tdiff = $hour.":".$min.":".$sec;
    # return the output.
    return $tdiff;
}