#!/usr/local/bin/perl -w
use strict;
use Fcntl ':flock';
my $file = "inputdata.txt";
open(INFILE, $file) or die "File Not Found: $!";
flock(INFILE, LOCK_EX);
my @students;
while (<INFILE>) {
   push @students, [split / /, $_];
}
my %hash;

# where's $grades coming from?
# $hash{$grades}= $students[0]*0.2 + $student[1]*0.25+$students[2]*0.25 + $student
+s[3]*0.3;

# flock(INFILE, LOCK_UN); # don't use unlock, it's done automagically by close()
close(INFILE);
##</code><code>##

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);