use strict;
use Fcntl ':flock';
my $file = "inputdata.txt";
open(FH, $file) or die "File Not Found: $!";
flock(FH, LOCK_EX);
my @students;
my %hash;
my @mul = (0.2,0.25,0.25,0.3);
while (<FH>) {
  my ($student, @grades) = (split ' ', $_); # split at one or more whitespaces
  my $grade = 0;
  for (0..$#mul) { $grade += $mul[$_] * $grades[$_] }
  $hash{$student} = $grade; # save the sum as a value to the student name
}
foreach my $key(sort {$hash{$b} <=> $hash{$a}} keys %hash){
  print "$key: $hash{$key}\n";
}
close(INFILE);