Run a standard unix process (not an app) on iPhone from OS X command line
You can't.

Jailed iOS devices have no method of executing any given program remotely. You'd have to jailbreak your device to be given access to terminal.

The iOS simulator is slightly different since it lacks many of the security features that the full iOS has, and since its running directly on your mac as child processes (rather than an emulator emulating a ARM processor).