I need to write a C program that will allow me to read/write files that are owned by root. However, I can only run the code under another user. I have the root password, but there are no "sudo" or "su" commands on the system, so I have no way of accessing the root account (there are practically no shell commands whatsoever, actually). I don't know a whole lot about UNIX permissions, so I don't know whether or not it is actually possible to do this without exploiting the system in some way or running a program owned by root itself (with +s or whatever). Any advice?
Thanks!
P.S. No, this isn't anything malicious, this is on an iPhone.
Under the UNIX permissions system, you need to run a file owned by root itself that's marked setuid-root (+s, as you said) or communicate with some process that is already running as root.
If there is no such file, you are out of luck.