So I have a third generation iPod Touch, with ios 4.2.1 and it's jailbroken. I'm using SSH to transfer files between it and my computer, but my problem is that when ever I add a file to it, and I want to take a look at it, I need to restart or respring my iPod before I can see it. So I've thought of a very tiny app placed at the homescreen, that resprings the iPod. My problems is that I don't know anything about coding for apple. Is there a 'one line solution' for this?
I don't know exactly what you mean by transferring files. Are you referring to transferring apps?
If so, you can make newly installed (via SSH copy) apps appear on the home screen by SSHing in to your phone and doing this
>ssh mobile@ipod
>uicache
or
>ssh root@ipod
>su mobile -c uicache
depending on whether you have your iPod setup to allow logins as root or mobile. Obviously, in my above example, you must have the IP address of your iPod mapped to the hostname "iPod", or else use IP addresses.
Another option that you may or may not be aware of is the SBSettings app itself. If you install that from Cydia, it has a really nice toggle to simply respring. That's not much more work than having a "tiny app" to respring (one extra touch, I guess).
If you are writing an Objective-C iOS app, and you want to do this programmatically (which wasn't 100% clear in the question), then check out this answer. And see here for information on using notify_post