CGI::Fast - CGI Interface for Fast CGI
use CGI::Fast
socket_path => '9000',
socket_perm => 0777,
listen_queue => 50;
use CGI qw/ :standard /;
$COUNTER = 0;
# optional, will default to STDOUT, STDERR
CGI::Fast->file_handles({
fcgi_output_file_handle => IO::Handle->new,
fcgi_error_file_handle => IO::Handle->new,
});
while ($q = CGI::Fast->new) {
process_request($q);
}
CGI::Fast is a subclass of the CGI object created by CGI.pm. It is
specialized to work with the FCGI module, which greatly speeds up CGI
scripts by turning them into persistently running server processes.
Scripts that perform time-consuming initialization processes, such as
loading large modules or opening persistent database connections, will
see large performance improvements.
Note that as CGI::Fast is based on CGI.pm it is no longer advised as
a way to write Perl web apps. See https://metacpan.org/pod/CGI#CGI.pm-HAS-BEEN-REMOVED-FROM-THE-PERL-CORE
for more information about this
In order to use CGI::Fast you'll need the FCGI module. See
http://www.cpan.org/ for details.
FastCGI scripts are persistent: one or more copies of the script
are started up when the server initializes, and stay around until
the server exits or they die a natural death. After performing
whatever one-time initialization it needs, the script enters a
loop waiting for incoming connections, processing the request, and
waiting some more.
A typical FastCGI script will look like this:
#!perl
use CGI::Fast;
do_some_initialization();
while ($q = CGI::Fast->new) {
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 (CGI::Fast->new) {
process_request();
}
Calls to header(), start_form(), etc. will all operate on the
current request.
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.
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.
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.)
You can set these as ENV variables or imports in the use CGI::Fast statement.
If the ENV variables are set then these will be favoured so you can override
the import statements on the command line, etc.
- FCGI_SOCKET_PATH / 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_SOCKET_PERM / socket_perm
-
Permissions for UNIX Domain socket.
- FCGI_LISTEN_QUEUE / listen_queue
-
Maximum length of the queue of pending connections, defaults to 100.
For example:
use CGI::Fast
socket_path => "sputnik:8888",
listen_queue => "50"
;
use CGI qw/ :standard /;
do_some_initialization();
while ($q = CGI::Fast->new) {
process_request($q);
}
Or:
use CGI::Fast;
use CGI qw/ :standard /;
do_some_initialization();
$ENV{FCGI_SOCKET_PATH} = "sputnik:8888";
$ENV{FCGI_LISTEN_QUEUE} = 50;
while ($q = CGI::Fast->new) {
process_request($q);
}
Note the importance of having use CGI after use CGI::Fast as this will
prevent any CGI import pragmas being overwritten by CGI::Fast. You can
use CGI::Fast as a drop in replacement like so:
use CGI::Fast qw/ :standard /
FCGI defaults to using STDOUT and STDERR as its output filehandles - this
may lead to unexpected redirect of output if you migrate scripts from CGI.pm
to CGI::Fast. To get around this you can use the file_handles method, which
you must do before the first call to CGI::Fast->new. For example using
IO::Handle:
CGI::Fast->file_handles({
fcgi_output_file_handle => IO::Handle->new,
fcgi_error_file_handle => IO::Handle->new,
});
while (CGI::Fast->new) {
..
}
Overriding STDIN using the fcgi_input_file_handle key is also possible,
however doing so is likely to break at least POST requests.
I haven't tested this very much.
Copyright 1996-1998, Lincoln D. Stein. All rights reserved. Currently
maintained by Lee Johnson
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:
https://github.com/leejo/cgi-fast
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the CGI::Carp manpage, CGI
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