CGI::Fast(3) Perl Programmers Reference Guide CGI::Fast(3)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 Mar
ket FastCGI standard, which greatly speeds up CGI scripts
by turning them into persistently running server pro
cesses. Scripts that perform time-consuming initializa
tion processes, such as loading large modules or opening
persistent database connections, will see large perfor
mance 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 Commu
nications 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. Pre
compiled binaries are available for several platforms,
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 conse
quences.
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. 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 fol
lowing to srm.conf:
AppClass /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.
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
This section intentionally left blank.
SEE ALSO
the CGI::Carp manpage, the CGI manpage
2001-02-22 perl v5.6.1 CGI::Fast(3)