DMCGI Guild

Calling all DMCGI gurus!

Mon, 15 Oct 2007 16:20:50 GMT

We need more activity! If you have an idea of an article to write about DMCGI, send me an e-mail at sineful (at) cox (dot) net with "BYOND: DMCGI Guild" as the subject and with the topic of your proposed article, and I'll see about getting you set up with the guild.

Installing DMCGI as a normal user on a Linux system w/ Apache

Wed, 13 Jun 2007 01:57:35 GMT

Installing DMCGI as a normal user on Linux isn't as fun as installing it as root.

First off, as with the root installation, you need to download and install BYOND, by unzipping it then going to the "byond/" directory and running the 'make here' command.

If you try to run a DMCGI application now, you'll undoubtedly fail. First, go to your BYOND installation, and use the `pwd` command to get the working directory to your "byond/bin/" directory. Record this for later usage. For this article, I will use "/home/audeuro/byond/bin" as my working directory.

First off, you need to set up your .htaccess file in your root web directory. In this .htaccess file, put the following:

Options +ExecCGI

This will tell Apache to allow execution of CGI in that particular web directory (and all children, if not specified otherwise in their .htaccess files). That should take care of that part, on to the next!

Upload your DMCGI application and CHMOD it to 755. Now there's just one step left.

Since you installed BYOND as a normal user, you'll undoubtedly get errors if you attempt to run this DMCGI application as-is. Next, we must create the last piece of the puzzle: a simple wrapper. The wrapper must be used so that DreamDaemon knows where it will be able to locate the libraries it needs to operate properly. Your wrapper should be a .cgi file. Mine was named index.cgi. You must use this script in order to utilize the DMCGI application. It should look like this:

#!/bin/sh

# LD_LIRARY_PATH is where DreamDaemon will look for the libraries.

# Set it to the above located working directory. Mine was /home/audeuro/byond/bin.

export LD_LIBRARY_PATH=/home/audeuro/byond/bin

# Now we execute DreamDaemon, which is where our world/executor was pointed at.

exec /home/audeuro/byond/bin/DreamDaemon /home/audeuro/www/index.dmb -CGI -logself -trusted

Now, CHMOD the just-created index.cgi to 755, and you should be good to go!

Installing DMCGI as root on an Apache Linux system.

Wed, 13 Jun 2007 00:24:59 GMT

Installing DMCGI as root is pretty simple, this will show you how to install DMCGI as root on any Linux server running Apache.

First you need to download and install BYOND as root, this is accomplished by unzipping the byond_linux.zip file, navigating to the newly created 'byond' directory and running the 'make install' command.

After that you need to configure Apache to recognize the .dmb extension as a valid CGI extension. Open your 'apache2.conf' or 'httpd.conf' file in your favorite text editor and search for the line 'AddHandler cgi-script' if found uncomment it (if commented) and add 'dmb' to the end of it. If you don't find it simply add the line

AddHandler cgi-script dmb

Next you'll want to find the 'DirectoryIndex' line and add index.dmb as a valid index file. After that's all done save the file and restart Apache.

Now upload your DMCGI file and CHMOD it to 755, you should be ready to rock. If you encounter any problems just head on over to the Installation forum and we'll give you a hand.

Connecting to MySQL databases with DMCGI

Wed, 13 Jun 2007 00:17:58 GMT

Here's a little diddy showing how to connect to a MySQL database using DMCGI.

#include <dantom\db\db.dme> // Include the DB library.

CGI/Topic(href,href_list[])
    var/output = "<HTML>&lt;BODY&gt;"
    if(href_list["getdata"])
        var
            data = href_list["getdata"]
            DBConnection/dbcon = new() //  New connection object.
            connected = dbcon.Connect("dbi:mysql:my_database:localhost:3306","username","password")
            // The Connect() proc hooks you up to the database using MySQL's 'dbi' handler.
        if(!connected) // No connection.
            usr << connected.ErrorMsg() // Error.
            return
        var/sql = "SELECT '[data]' FROM my_table" // Simple MySQL query.
        var/DBQuery/query = new() // Creates a new query object.
        connected = query.Execute(sql) // Reuse the connected var.
        if(!connected)  // Query failed.
            usr << query.ErrorMsg() // Error.
            return
        while(query.NextRow()) // Loops over the rows matching your query
            var/rdat = query.GetColumnData() // Little proc that converts the data from numbers to text indexes.
            for(var/R in rdat) // Loop over everything it finds.
                output += "[R]: [rdat[R]]" // And output it.
        // Close up the database connections and whatnot
        query.Close()
        dbcon.Close()
        del(query)
        del(dbcon)
    else // Simple form to select which information you want
        output += {"<form action="?" method="GET">
                  Get Some Data: <input type="text" value="getdata">
                  <input type="submit"></form>"}
    output += "&lt;/BODY&gt;</HTML>"
    usr << output

Note: This is to LEARN from, this code won't work just because. Various values must be changed for it to even connect to your database.

Communicating with your game using DMCGI.

Wed, 13 Jun 2007 00:16:36 GMT

Say you want to communicate with your game with a DMCGI script, no problem -- it's easy!

This will be your game's source

world/Topic(href)
    var/list/hlist = params2list(href) // Similar to href_list[] in CGI/Topic()
    if(hlist["message"])
        world << "Remote message: [hlist["message"]]"
        . = "Message sent."
    else
        . = "Something didn't work..."

This will be your DMCGI source

#define GAME_ADDR "localhost:1234" // Address to your game

CGI/Topic(href,href_list[])
    if(!href)
        usr << {"<form action="?" method="GET">
Message: <input type="text" value="message"> <input type="submit"></form>"}
    else
        if(href_list["message"])
            usr << world.Export("byond://[GAME_ADDR]?message=[href_list["message"]]")
        else
            usr << "Hmm, that didn't work!"

Something like that should get you on your way to having nice DMCGI/Game communications, enjoy!

Using HTML forms.

Wed, 13 Jun 2007 00:15:21 GMT

// This is an example of how to use HTML forms with DMCGI

CGI
    Topic(href,href_list[])
        if(href) // Sanity check
            if(href_list["value"])
                usr << "You entered: [href_list["value"]]"
            else
                usr << "You brokerated it, fiend!"
        else
            usr << {"Please enter a value: 
<form action="?" method="GET">
<input type="text" name="value">
<input type="submit"></form>"}

href and href_list are simply the arguments passed to your DMCGI application. href is a simple text version and href_list is the result of params2list(href).

Hello World!

Tue, 12 Jun 2007 23:58:29 GMT

// This is a simple DMCGI 'Hello World' program

#include <dantom\cgi\CGI.dme>

CGI
    Topic() // This is called everytime a page is loaded
        usr << browse("Hello world!") // Outputs 'Hello world!' to the user.

As a note, in pure CGI mode simply using

usr << "Hello world!"

Would have the same effect, using browse() is helpful for testing within Dream Seeker.