/************************************************/
void process(void){
pid_t pid;
if((pid = fork())<0)
    printf("error at 1\n");
  else if (pid == 0){
    if(execl("/home/xsajlar/Test_Prog/timing/run",
"run",NULL) <0)
     printf("error at 2\n");

   }
   if(waitpid(pid, NULL,0)<0)
     printf("error at 3\n");

  clock_t start, stop, duration;
  struct timeval first_time, sec_time;
  float tot_time;

  gettimeofday(&first_time, NULL);
  start = clock();
  /**Want to time this part**/  
  process();
 /**************************/  

  stop = clock();
  gettimeofday(&sec_time, NULL);
  tot_time = (float)(sec_time.tv_usec - first_time.tv_usec)*1.0e-6;

  printf("first_time = %f\n",(float)first_time.tv_usec);
  printf("sec_time = %f\n",(float)sec_time.tv_usec);
  printf("tot from gettimeofday = %f sec (real time)\n",tot_time);

  duration = stop - start;
  printf("tot time fom clock =  %f sec (user time) \n",
     ((double) (stop - start)) / CLOCKS_PER_SEC);
  exit(0);
 return 0;

clock_t    startTime = clock();
/* timed code here */
clock_t    stopTime = clock();
clock_t    totalTime = stopTime - startTime;
clock_t    totalTimeInSeconds = totalTime / CLOCKS_PER_SEC;

and if you need a more precise value, you could use floats (i'm assuming
that clock_t can be cast to a float, if not someone correct me)
float        totalTime = (float)stopTime - (float)startTime;
float        totalTimeInSeconds = totalTime / (float)CLOCKS_PER_SEC;

not sure if that last cast is necessary.  if CLOCKS_PER_SEC is #define'd, it
should work fine without it