#!/usr/bin/perl
use strict;
use warnings;
use LWP::Simple;
use IO::Handle;
STDOUT->autoflush(1);

$ARGV[0] = "" unless defined $ARGV[0];
my $url = $ARGV[0];
if( $url !~ /\/download$/ ){
  $url = $url . "/download";
}
print "Content-Type: application/pdf\n\n";
getprint($url);

<embed src="http://cgi.example.com/pdf.cgi?http://nextcloud.example.com/index.php/s/XXXXXXXXXXXXXXX" type="application/pdf" width="640px" height="480px">