Add disk io information per process

[yuxincs]

Describe the solution you'd like Add disk io information per process, perhaps in si.cpu() or additional items in si.diskIO().

Describe alternatives you've considered Sorry I don't know much about windows APIs, so no solutions in windows.

For Linux, parsing /proc/[pid]/io would work.

For macOS, many solutions require sudo (such as using iotop, which also requires disabling SIP). I happen to find this solution which seems to work.

Below is a proof-of-concept using that solution:

#include <stdio.h>
#include <libproc.h>
#include <sys/resource.h>

int main() {
  pid_t pid = 0;
  printf("PID: ");
  scanf("%d", &pid);
  rusage_info_current rusage;
  if (proc_pid_rusage(pid, RUSAGE_INFO_CURRENT, (void **)&rusage) == 0)
  {
    printf("Bytes read: %llu\n", rusage.ri_diskio_bytesread);
    printf("Bytes written: %llu\n", rusage.ri_diskio_byteswritten);
  }
  return 0;
}

which gives me (10.15.1 Catalina with SIP enabled) the desired information, same as the one given in Activity Monitor:

PID: 179
Bytes read: 1109225472
Bytes written: 1863680

Additional context We might have permission issues when accessing the disk io for certain processes. In that case, I think maybe it's acceptable to list the information as undefined or something?