Perl FCGI Error: mod_fcgid: error reading data from FastCGI server

knox has asked for the wisdom of the Perl Monks concerning the following question:

Hello Monks,

Your wisdom once again is appreciated. I've been testing some FCGI scripts, I've managed to get CGI::Fast working, but I'd like to get FCGI working. Unfortunately, I haven't be able to find good working examples. I'd like to see an example of FCGI return $ENV vars, similar to the CGI::Fast used in the Apache example: https://httpd.apache.org/mod_fcgid/mod/mod_fcgid.html. The code posted below is just me trying to get something to work, it is giving an internal server error. I've posted this is from my error log:

[Mon Jan 27 19:44:02.915926 2020] [fcgid:warn] [pid 20681] (104)Connec
+tion reset by peer: [client xx.xxx.xxx.xxx:xxxxx] mod_fcgid: error re
+ading data from FastCGI server
[Mon Jan 27 19:44:02.915973 2020] [core:error] [pid 20681] [client xx.
+xxx.xxx.xxx:xxxxx] End of script output before headers: test.fcgi
<code>

<code>
#!/usr/bin/perl
use FCGI;
use CGI::Carp qw(fatalsToBrowser warningsToBrowser);
use Encode;

#use CGI::Fast; 
#the CGI:Fast example from https://httpd.apache.org/mod_fcgid/mod/mod_
+fcgid.html is working; my FCGI example is not.


my $count = 0;
my $request = FCGI::Request();

while($request->Accept() >= 0) {
   $body   = "Content-type:text/html; charset=utf-8\r\n\r\n";
   $body   .= '<html><head><meta http-equiv="Content-Type" content="te
+xt/html; charset=utf-8" /></head><body>';
   $body .= '<h1>Woohoooo!</h1>':
   $body .= '</body></html>';
   $body .= '</body></html>';
   $body = encode_utf8($body);
   
   print $body;

}
[download]

Aside from that, I have a very basic question with FastCGI - as it keeps a persistent connection, whats the best way to temporarily test it? I am new to FastCGI, it is compelling, but I don't know the vernacular to describe it well (yet). Let me know if the above doesn't make sense. Secondly, is there a way to get more descriptive error messages than the ones that come out of apache.log?

And yes! I will look into frameworks like Plack/Dancer - but before I do, I'd like to get grasp of how FCGI works before I put a layer on top of it.

Comment on Perl FCGI Error: mod_fcgid: error reading data from FastCGI server Download Code

Replies are listed 'Best First'.
Re: Perl FCGI Error: mod_fcgid: error reading data from FastCGI server by hippo (Bishop) on Jan 28, 2020 at 12:15 UTC
The code posted below is just me trying to get something to work, it is giving an internal server error. That's because it doesn't compile: $ perl -cw 11111940.pl Status: 500 Content-type: text/html <h1>Software error:</h1> <pre>syntax error at 11111940.pl line 16, near "'<h1>Woohoo +oo!</h1>':" 11111940.pl had compilation errors. </pre> <p> For help, please send mail to this site's webmaster, giving this error + message and the time and date of the error. </p> [Tue Jan 28 12:12:01 2020] 11111940.pl: syntax error at 11111940.pl li +ne 16, near "'<h1>Woohoooo!</h1>':" [Tue Jan 28 12:12:01 2020] 11111940.pl: 11111940.pl had compilation er +rors. [download] If you fix your punctuation you might have better luck.	[reply] [d/l]
Re^2: Perl FCGI Error: mod_fcgid: error reading data from FastCGI server by knox (Sexton) on Jan 28, 2020 at 19:30 UTC
thank you.	[reply]
Re: Perl FCGI Error: mod_fcgid: error reading data from FastCGI server by Anonymous Monk on Jan 28, 2020 at 10:59 UTC
I've managed to get CGI::Fast working, but I'd like to get FCGI working. you just did; conveniences are convenient In order to use CGI::Fast you'll need the FCGI module I'd like to see an example of FCGI return $ENV vars https://metacpan.org/source/ETHER/FCGI-0.79/eg/echo.pl very basic question with FastCGI - as it keeps a persistent connection, whats the best way to temporarily test it? test what? https://metacpan.org/source/LEEJO/CGI-Fast-2.15/t/007_socket_perm.t	[reply]
Re^2: Perl FCGI Error: mod_fcgid: error reading data from FastCGI server by knox (Sexton) on Jan 28, 2020 at 21:03 UTC
Superb, thank you for the answers and all the examples - exactly what I needed to push me along for learning Perl, despite having a typo in my code. The socks example was exactly what i meant for testing, without saying succinctly what it was; the code example will be useful for my project. To clarify (for me, and for other new learners), CGI::Fast is a "wrapper" for FCGI module. The reason for trying FCGI was following the advice from https://metacpan.org/pod/CGI::Fast "CGI::Fast is based on CGI.pm it is no longer advised as a way to write Perl web apps". I am neutral on other's peoples use of CGI.pm, but as for myself, I want to move away from this module. I will acknowledge that CGI.pm has a great crash course in learning Perl. best, knox	[reply]
Re^3: Perl FCGI Error: mod_fcgid: error reading data from FastCGI server by Anonymous Monk on Jan 28, 2020 at 21:39 UTC
The reason for trying FCGI was following the advice from https://metacpan.org/pod/CGI::Fast "CGI::Fast is based on CGI.pm it is no longer advised as a way to write Perl web apps". you're totally missing the point of that propaganda , it isnt to reinvent CGI or use less convenient imitations... Re: Replacing CGI.pm is busywork Re^3: appending to html at beginning ( use CGI for parsing cgi) Re: CGI Parameters (CGI.pm, CGI::Fast )	[reply]
Re^4: Perl FCGI Error: mod_fcgid: error reading data from FastCGI server by knox (Sexton) on Jan 28, 2020 at 23:52 UTC
Re^5: Perl FCGI Error: mod_fcgid: error reading data from FastCGI server by Your Mother (Archbishop) on Jan 29, 2020 at 15:25 UTC
Some notes below your chosen depth have not been shown here
Re: Perl FCGI Error: mod_fcgid: error reading data from FastCGI server by knox (Sexton) on Jan 27, 2020 at 20:44 UTC
Quick note, this is for Apache24, not nginx	[reply]


"be consistent"
	PerlMonks