I want to get notified every time a program performs any type of I/O system call. I want to see the parameters and the data being copied. I also want the opportunity to cancel the system call and even return fake results and data back to the program.

I already use strace to understand what programs do but it would be great if I could also intercept these calls in real time. Just keep the program waiting until I approve its open system call on that specific file.