I just wanted to say that I'm a new PERL programmer and I have lots of things to learn. I've been working on this program for some time. I'm having trouble with opening and closing and writing to my file. Here's what I got so far: 
use strict;
my @data;
my $avg;
my $dev;
my $std;
my $tmp;
my $grade;
my $line;

open(IN, "pa5c.dat") || die ("Can't open file $!\n");
while($line = <IN>){
          chomp ($line);
         my $tmp = [split /:/];
          $avg += $tmp->[1];
          push @data, $tmp;

}
$avg = scalar(@data) ? $avg /= @data : 0;


my $std = 0;
for (@data) { $std += abs($_->[1] - $avg) }
        $std = scalar(@data) ? $std /= @data : 0;

open(OUT, ">pa5c.dat") || die ("Can't open file $!\n");
        for (@data) {
          my $grade;
          my $dev = ($_->[1] - $avg) / $std;
          if ($dev >= 1) { $grade = 'A' }
          elsif ($dev >= (1/3)) { $grade = 'B' }
         elsif ($dev >= (-1/3)) { $grade = 'C' }
         elsif ($dev > -1) { $grade = 'D' }
         else { $grade = 'E' }
         print OUT join (':', $_->[0], $_->[1], $grade) . "\n";
}

close OUT;


__END__#pa52.pl

[download]
The pa5c.dat file contains: 
Smith:70
Jones:74
Rider:80
High:82
Billie:68
Smithsonville:76

[download]
Now if my program runs correctly, my program should assign letter grades to the students.

In reply to Filehandles - opening/closing a filehandle by yabba

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