strace tells you every syscall the process under it makes. So very helpful to understanding how a program interacts with the operating system - and I/O as all

strace tells you every syscall the process under it makes. So very helpful to understanding how a program interacts with the operating system - and I/O as all IO mechanisms are managed by the operating system. As for how to filter this I'll leave that to the other comments, but I personally would look at the man page or Google around for tips