CGI::Fast(3p) Perl Programmers Reference Guide CGI::Fast(3p)NAMECGI::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;
}
DESCRIPTIONCGI::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 con-
nections, 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 Information 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. Precom-
piled binaries are available for several platforms, includ-
ing 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 interpreters, 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.
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CGI::Fast(3p) Perl Programmers Reference Guide CGI::Fast(3p)
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 follow-
ing 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 benefit.
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CGI::Fast(3p) Perl Programmers Reference Guide CGI::Fast(3p)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 can 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.
AUTHOR INFORMATION
Copyright 1996-1998, Lincoln D. Stein. All rights reserved.
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@cshl.org
BUGS
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SEE ALSO
CGI::Carp, CGI
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