CGI::Fast - phpMan

CGI::Fast(3pm) Perl Programmers Reference Guide CGI::Fast(3pm)

NAME
CGI::Fast - CGI Interface for Fast CGI

SYNOPSIS
use CGI::Fast qw(:standard);
$COUNTER = 0;
while (new CGI::Fast) {
print header;
print start_html("Fast CGI Rocks");
print
h1("Fast CGI Rocks"),
"Invocation number ",b($COUNTER++),
" PID ",b($$),".",
hr;
print end_html;
}

DESCRIPTION
CGI::Fast is a subclass of the CGI object created by CGI.pm. It is specialized to
work well with the Open Market FastCGI standard, which greatly speeds up CGI
scripts by turning them into persistently running server processes. Scripts that
perform time-consuming initialization processes, such as loading large modules or
opening persistent database connections, will see large performance improvements.

OTHER PIECES OF THE PUZZLE
In order to use CGI::Fast you'll need a FastCGI-enabled Web server. Open Market's
server is FastCGI-savvy. There are also freely redistributable FastCGI modules for
NCSA httpd 1.5 and Apache. FastCGI-enabling modules for Microsoft Internet Infor-
mation Server and Netscape Communications Server have been announced.

In addition, you'll need a version of the Perl interpreter that has been linked
with the FastCGI I/O library. Precompiled binaries are available for several plat-
forms, including DEC Alpha, HP-UX and SPARC/Solaris, or you can rebuild Perl from
source with patches provided in the FastCGI developer's kit. The FastCGI Perl
interpreter can be used in place of your normal Perl without ill consequences.

You can find FastCGI modules for Apache and NCSA httpd, precompiled Perl inter-
preters, and the FastCGI developer's kit all at URL:

http://www.fastcgi.com/

WRITING FASTCGI PERL SCRIPTS
FastCGI scripts are persistent: one or more copies of the script are started up
when the server initializes, and stay around until the server exits or they die a
natural death. After performing whatever one-time initialization it needs, the
script enters a loop waiting for incoming connections, processing the request, and
waiting some more.

A typical FastCGI script will look like this:

#!/usr/local/bin/perl # must be a FastCGI version of perl!
use CGI::Fast;
&do_some_initialization();
while ($q = new CGI::Fast) {
&process_request($q);
}

Each time there's a new request, CGI::Fast returns a CGI object to your loop. The
rest of the time your script waits in the call to new(). When the server requests
that your script be terminated, new() will return undef. You can of course exit
earlier if you choose. A new version of the script will be respawned to take its
place (this may be necessary in order to avoid Perl memory leaks in long-running
scripts).

CGI.pm's default CGI object mode also works. Just modify the loop this way:

while (new CGI::Fast) {
&process_request;
}

Calls to header(), start_form(), etc. will all operate on the current request.

INSTALLING FASTCGI SCRIPTS
See the FastCGI developer's kit documentation for full details. On the Apache
server, the following line must be added to srm.conf:

AddType application/x-httpd-fcgi .fcgi

FastCGI scripts must end in the extension .fcgi. For each script you install, you
must add something like the following to srm.conf:

FastCgiServer /usr/etc/httpd/fcgi-bin/file_upload.fcgi -processes 2

This instructs Apache to launch two copies of file_upload.fcgi at startup time.

USING FASTCGI SCRIPTS AS CGI SCRIPTS
Any script that works correctly as a FastCGI script will also work correctly when
installed as a vanilla CGI script. However it will not see any performance bene-
fit.

EXTERNAL FASTCGI SERVER INVOCATION
FastCGI supports a TCP/IP transport mechanism which allows FastCGI scripts to run
external to the webserver, perhaps on a remote machine. To configure the webserver
to connect to an external FastCGI server, you would add the following to your
srm.conf:

FastCgiExternalServer /usr/etc/httpd/fcgi-bin/file_upload.fcgi -host sputnik:8888

Two environment variables affect how the "CGI::Fast" object is created, allowing
"CGI::Fast" to be used as an external FastCGI server. (See "FCGI" documentation
for "FCGI::OpenSocket" for more information.)

FCGI_SOCKET_PATH
The address (TCP/IP) or path (UNIX Domain) of the socket the external FastCGI
script to which bind an listen for incoming connections from the web server.

FCGI_LISTEN_QUEUE
Maximum length of the queue of pending connections.

For example:

#!/usr/local/bin/perl # must be a FastCGI version of perl!
use CGI::Fast;
&do_some_initialization();
$ENV{FCGI_SOCKET_PATH} = "sputnik:8888";
$ENV{FCGI_LISTEN_QUEUE} = 100;
while ($q = new CGI::Fast) {
&process_request($q);
}

CAVEATS
I haven't tested this very much.

This library is free software; you can redistribute it and/or modify it under the
same terms as Perl itself.

Address bug reports and comments to: lstein AT cshl.org

BUGS
This section intentionally left blank.