Calling all Android hackers ..... Will this idea work?

I have a phone with some text messages on it from a dear friend who has passed away. I don t have the required permissions to pull the mmssms.db file using ADB. Only an app with permission to access messages can do that. The file is specifically excluded from a full backup. And there is no sudo command in Android :(

Could I write a little app that asks for permission to access messages and the SD card; then just reads the file contents and writes them out unaltered to a file on the SD card (or even just use system() to issue a cp command to the shell)? I d only need to run it once and then uninstall it. The output file on the SD card would be owned by my app, so I should be able to chmod it at least 664 and then the ADB shell user would be able to read it, so I could pull it to my (Ubuntu) laptop and use sqlite to query just the messages out of it that I want to archive.

Please, no code spoilers or links to ready-made SMS backup apps. I m not asking *how* to do this: if it s possible, I d like to figure out how on my own terms. (Learning a new programming language would be fun and anyway, it s still all just function()s and {posh brackets} so I must already be about halfway there.) I would just like to be sure, before I start, if or not this method stands a chance of working at all, or there s a reason I have not thought of why it would be a hiding to nothing?