httpd write file out from within cgi script

Hi:

I want to write a file out from within a perl cgi script. This is obviously not possible in the standard configuration of httpd. The normal output works perfectly. What is to do?

#!/usr/bin/perl

print("Content-Type: text/html; charset=ascii\n\n");
print("hello world"); # works
# no error but not found in file system after the script finished
open(my $fh, ">", "out") or die $!;
print($fh "foo");
close($fh);

OpenBSD 6.1

Many thanks in advance.