create personalized binary without having to recompile

[niko]

Hello,

I would like to create personalized compiled application - which should be a single-exe-file on windows, and a single application-bundle on mac.
The user should download the file through http - and the webserver should personalize the file for every use - without having to compile the application every time.

Is there a possibility to have somewhere in the binary some "space" where I can place such user-data without corrupting the binary? When running the binary it could open itself and get the personalized data out of it.

thanks,
niko

[marcel]

Why not put the personalized data in a separate file, with a generic format?
The application can read the data from that file.

[niko]

I would like to provide a single-exe the user just has to start
(no installer, no zip-file to extract, just one exe)

[wysota]

You can place a static const char* buffer in the application. Then after the compilation simply find the buffer in memory and replace that part of file with something else when you need it. Should work fine...

[niko]

thanks, I will try that!

however it won't work when packing the executable using UPX (to get a smaller download-filesize)
any ideas for that case?

niko

[jacek]

You could write something similar to UPX, that will take the executable and the data and combine them into a new executable, that loads the data into memory and starts the original application.

[wysota]

Or you can call upx on the resulting executable after substituting the block.

[Brandybuck]

Some installers are scriptable. You could generate the installer on the fly when the user requests the download. I know of a few companies that "inject" personal license keys this way.

[niko]

much thanks for those tips!!

niko