For those that aren't familar, in Apache 1.2 and prior, you had to name your script "nph-process.cgi", with then 'nph-' part meaning 'Non-Parsed Headers'.
In Apache 1.3, this seems to have changed. The following notice has been posted in the
Apache 1.3 upgrade notes:
Apache now provides an effectively unbuffered connection for CGI scripts. This means that data will be sent to the client as soon as the CGI pauses or stops output; previously, Apache would buffer the output up to a fixed buffer size before sending, which could result in the user viewing an empty page until the CGI finished or output a complete buffer. It is no longer necessary to use an "nph-" CGI to get unbuffered output. Given that most CGIs are written in a language that by default does buffering (e.g., perl) this shouldn't have a detrimental effect on performance.
"nph-" CGIs, which formerly provided a direct socket to the client without any server post-processing, were not fully compatible with HTTP/1.1 or SSL support. As such they would have had to implement the transport details, such as encryption or chunking, in order to work properly in certain situations. Now, the only difference between nph and non-nph scripts is "non-parsed headers".
For whatever reason, though, using Apache 1.3.26, I find I still have to name the script 'nph-process.cgi'. For good measure, I also did this:
my $q = CGI->new();
print $q->header(-nph => 1);
