usergen

#!/usr/bin/perl

use bytes;
use Digest::SHA;
use MIME::Base64;
use Math::BigInt;

($path_to_file, $pass, $salt) = @ARGV;

unless (defined($salt)) {
    print "Insufficient parameters", "\n", "Use: usergen <path_to_userlist_file> <pass> <salt>", "\n";
    exit 1;
}

my $handle;
unless (open $handle, "<:encoding(utf8)", $path_to_file) {
   print STDERR "Could not open file '$path_to_file': $!\n";
   exit 2;
}

chomp(my @names = <$handle>);

unless (close $handle) {
   # what does it mean if close yields an error and you are just reading?
   print STDERR "Error while closing '$path_to_file': $!\n";
} 


$names_size = scalar @names;

$hash = Digest::SHA::sha1_hex($salt, $pass);
$hash_num = Math::BigInt->from_hex($hash);
$index = $hash_num->bmod($names_size);
$index = $index->numify();
$number = $hash_num->bmod(989)->numify() + 11;

print $names[$index], $number, "\n";