Re^2: How a web server sending data to a CGI perl script ?

[exilepanda]

Thanks Ed, I might want to do the things as your described ( 2nd client ), but the fact is that I already stuck at the first client.

From a CGI script perspective, when it's triggered by the server, the script will naturally have all relevant %ENV variables like REMOTE_ADDR, COOKIE, REQUEST_METHOD etc.

So that my very root question is how these $ENV variables are sent to the CGI script before the first line of code in the CGI script is run ?

[flexvault]

Hello exilepanda,

If you do it the way I described, the %ENV variables are already set-up for you. Do not touch the %ENV, but copy the %ENV to a temp hash. And remember you still need the GET / POST data ( the actual $Todo work ) from the WebServer. ( Example ).

    my $Todo = ...;    # Data sent via GET or POST from browser via We
+bServer    
    my $environment = '';
    foreach my $env ( keys %ENV )
    {   $environment .= "$env\t$ENV{$env}\n"; }

    my $send = pack("N",length($environment) ) . $environment .  pack(
+"N",length($Todo) ) . $Todo;
    my $ret = send_data( $svr, \$send );   # Send to processing Perl s
+cript

Now the second client has the environment of the WebSever, and it's own %ENV from Perl. The processing client uses %TempENV for WebServer info and it's own %ENV if it needs it.

It's clean and you don't have to get into the error handling of the WebServer.

Good Luck!

Regards...Ed

[Anonymous Monk]

$ cat shabba
for my $key ( grep /perl/i , keys %ENV ){ print qq{ $key $ENV{$key}\n}
+; }

$ perl shabba
 PERL_MB_OPT  --config installhtmldir=  --binhtml=

$ perl -e " $ENV{PERL_SHABBA}=666; system $^X, q{shabba}; "
 PERL_SHABBA 666
 PERL_MB_OPT  --config installhtmldir=  --binhtml=  --config installht
+mldir=  --binhtml=

$ perl shabba
 PERL_MB_OPT  --config installhtmldir=  --binhtml=

[exilepanda]

Oh Wow!! Surprised!!! Great demonstration and works perfectly! And I just notice the system() or the backticks ( the right tool for my case ) are actually kind of fork thing... which is the "how" that I exactly asking! Thanks man!

Though.. what still puzzle me is how do you leave the <STDIN> open for the CGI to read() in this code pattern ?

[Anonymous Monk]

Its not a pattern, just shows %ENV is inherited from parent process

Its one part of what HTTP::Request::AsCGI does, STDIN... stuff is the other part