How can I run a CGI::Application run mode from the command line?

Question

I have a run mode in my CGI::Application web-app that I would like to be able to trigger from the command line so i can automate it. From the web-app's perspective it does some processing then sends the results in an email.

When called from the web interface it passes in a set of parameters (email address, which query to run, date, etc) so these need to be passed in.

How can I construct a call to the CGI::Application app that will be the same as if I ran it from the web?

Answer 1

The original CGI specification makes it easy to run things from the command line and was fully intended not as a specific HTTP-only interface but something that could handle FTP and gopher as well as new top-level URL schemes. I know what I wanted when I helped specify it.

The spec I referenced should give you all you need, but for the most part it is just a collection of environment variables. If you see a request for:

http://some.server.com/some/path?a=b&c=d

The environment variables come out looking like this:

SERVER_PROTOCOL=http
REQUEST_METHOD=GET
HTTP_HOST=some.server.com
SERVER_PORT=80
PATH_INFO=/some/path
QUERY_INFO=a=b&c=d

To reverse the polarity of that in Perl would go something like this:

$ENV{'SERVER_PROTOCOL'} = 'http';
$ENV{'REQUEST_METHOD'} = 'GET';
$ENV{'SERVER_PORT'} = 80;
$ENV{'PATH_INFO'} = '/some/path';
$ENV{'QUERY_INFO'} = 'a=b&c=d';
system("perl your-CGI-script.pl");

Things get a bit more complicated in handling POST queries and there are more possible environment variables that may be required. Worst case you can enumerate them all with a quick CGI script something like:

print "Content-Type: text/plain\r\n\r\n";
foreach (keys(%ENV))
{
    print "$_=$ENV{$_}\r\n";
}

Now put that on the web server in place of your CGI script and you'll see all the environment that gets passed in (and the original environment so you'll need to make a few judgement calls).

Answer 2

Upon further digging through the CGI::App and the CGI documentation, it appeared to be more straightforward than I thought. The simplest case (no real argument handling or dealing with the output from the webapp run call) is:

#!/usr/bin/perl

use strict;
use warnings;

use CGI;
use WebApp;

my $cgi = new CGI( \%{@ARGV} );

my $webapp = WebApp->new( QUERY => $cgi );
$webapp->run();

It just takes a series of space separated name value pairs to create the CGI. You need to pass in the run mode and all the arguments.