#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/wait.h>
#include <err.h>

int main(int argc, char * argv[]) {
  int rc;
  int pid;
  int status;
  struct rusage ru;

  if(argc < 2) {
    errx(1, "Usage: beancounter PROGRAM");
  }

  pid = fork();
  if(pid == 0) {
    rc = execve(argv[1], NULL, NULL);
    if(rc == -1)
      warn("fork() failed");
  }

  rc = wait4(pid, &status, 0, &ru);
  if(rc == -1)
    warn("wait4() failed");

#if 0
  struct rusage {
    struct timeval ru_utime; /* user time used */
    struct timeval ru_stime; /* system time used */
    long ru_maxrss;          /* maximum resident set size */
    long ru_ixrss;      /* integral shared memory size */
    long ru_idrss;      /* integral unshared data size */
    long ru_isrss;      /* integral unshared stack size */
    long ru_minflt;          /* page reclaims */
    long ru_majflt;          /* page faults */
    long ru_nswap;      /* swaps */
    long ru_inblock;         /* block input operations */
    long ru_oublock;         /* block output operations */
    long ru_msgsnd;          /* messages sent */
    long ru_msgrcv;          /* messages received */
    long ru_nsignals;        /* signals received */
    long ru_nvcsw;      /* voluntary context switches */
    long ru_nivcsw;          /* involuntary context switches */
  };
#endif

  printf("User time: %li.%li sec\n", ru.ru_utime.tv_sec, ru.ru_utime.tv_usec);
  printf("System time: %li.%li sec\n", ru.ru_stime.tv_sec, ru.ru_stime.tv_usec);
  printf("Maximum resident set size: %liKB\n", ru.ru_maxrss);
  printf("Integral shared memory size: %li KB/s\n", ru.ru_ixrss);
  printf("Integral unshared data size: %li KB/s\n", ru.ru_idrss);
  printf("Integral unshared stack size: %li KB/s\n", ru.ru_isrss);
  printf("Page reclaims (from cache): %li\n", ru.ru_minflt);
  printf("Page faults (requiring device I/O): %li\n", ru.ru_majflt);
  printf("Complete swaps to disk: %li\n", ru.ru_nswap);
  printf("Blocking noncached input operations: %li\n", ru.ru_inblock);
  printf("Blocking noncached output operations: %li\n", ru.ru_oublock);
  printf("SysV IPC Messages sent: %li\n", ru.ru_msgsnd);
  printf("SysV IPC Messages received: %li\n", ru.ru_msgrcv);
  printf("Signals received; %li\n", ru.ru_nsignals);
  printf("Voluntary context switches (timeslices not used up): %li\n", ru.ru_nvcsw);
  printf("Involuntary context switches (timeslices used up): %li\n", ru.ru_nivcsw);
  
  return 0;
}