Why do you call print with brackets then again without?

print ("Content-Type:application/x-download\n");
print "Content-Disposition: attachment; filename=$file\n\n";
[download]

Update: Looks like a copy/paste from SO https://stackoverflow.com/questions/15294815/perl-cgi-to-download-a-file-via-web-browser:

use CGI;
my $html= new CGI;
#get the file name from URL ex. http://<server_IP>/cgi-bin/download.cg
+i?a=testing.txt
my $file= $html->param('a'); 
# $file is nothing but testing.txt
my $filepath= "/var/www/upload/$file";

print ("Content-Type:application/x-download\n");
print "Content-Disposition: attachment; filename=$file\n\n";

open FILE, "< $filepath" or die "can't open : $!";
binmode FILE;
local $/ = \10240;
while (<FILE>){
    print $_;
}

    close FILE;
 # use Unlink if u want to delete the files after download.
#unlink ($filepath);
[download]

Ignoring the comment from davorg:

"Oops. I moved the articles around a bit. The link is not dead; it tells you where to go - perlhacks.com/articles/cgi-programming/cgi-programming-part-2. But to summarise, if I send you a file parameter of "../../../etc/passwd", you send me the file that contains all of your passwords for me to crack at my leisure. – Dave Cross Jan 19, 2017 at 5:56"