If you want to create a script that toggles a setting in a Source engine game like Left 4 Dead, you need to know the console variable name that controls it, but sometimes you don’t know.  One way to figure it out is to blindly search using the “find” command to look for a command that looks like it controls what you need.  The other way is to dump the cvar list to disk, change the setting in the GUI, dump the list again, and compare the two lists.

However the latter approach is not easy.  There is a condump command but it only dumps a limited amount of text, and the cvarlist command displays too much text for the console to hold (or dump).

However, taking advantage of the fact that cvars always start with a letter, we can brute force this.  First, clear any condump*.txt files from your Source engine mod folder (For Left 4 Dead, it’s Steam\common\Left 4 Dead\left4dead) and then run the following three commands in sequence:

clear; cvarlist a; condump; clear; cvarlist b; condump; clear; cvarlist c; condump; clear; cvarlist d; condump; clear; cvarlist e; condump; clear; cvarlist f; condump; clear; cvarlist g; condump; clear; cvarlist h; condump; clear; cvarlist i; condump

clear; cvarlist j; condump; clear; cvarlist k; condump; clear; cvarlist l; condump; clear; cvarlist m; condump; clear; cvarlist n; condump; clear; cvarlist o; condump; clear; cvarlist p; condump; clear; cvarlist q; condump; clear; cvarlist r; condump

clear; cvarlist s; condump; clear; cvarlist t; condump; clear; cvarlist u; condump; clear; cvarlist v; condump; clear; cvarlist w; condump; clear; cvarlist x; condump; clear; cvarlist y; condump; clear; cvarlist z; condump

(Three lines of commands are needed since there is a limit to the length of one console command.)

Now you have 26 condump files in your Source mod folder.  Move them to an empty temporary folder on your desktop or somewhere.  Now change the setting you’re trying to find the cvar for and runt he console commands again to get another batch of 26 files.  Move these to a SECOND temporary folder.

Then, download WinMerge (or use a similar file/directory comparison tool) and point it at both folders.  Bam.  It will instantly show you which dumped files changed, and you can then go into the files and see the changed values side by side.

Mine is here.  The biggest change is I’ve gone for the look of the new Windows 7 Content view for files and folders … I like it very much.

In addition I have removed most of the excess whitespace, added hover effects, and added tooltip info to images.  In addition there are custom icons for some different filetypes, and it’s easy to change those.

There are also a couple interesting statistics at the bottom.

Download the source here (requires 7zip or a tool that can extract .7z files to use).

Shockingly IE8RC1 renders it correctly without requiring any hacks.  I did not test it with IE7 (I’m scared to, given the semi-hackish way I got the folder/file lists working without tables).  The latest versions of Gecko, Webkit, and Opera all handle it fine… and of course Gecko and Webkit get fancy rounded borders too.

For the future I might add some javascript in to allow for custom sorting and maybe different views for files/folders… who knows.  But that would require coding a lot of the template over in JavaScript.