Starting at line 331 of proc/sysinfo.c

sysinfo snip.c

static void getrunners(unsigned int *restrict running, unsigned int *restrict blocked) {
  struct direct *ent;
  DIR *proc;

  *running=0;
  *blocked=0;

  if((proc=opendir("/proc"))==NULL) crash("/proc");

  while(( ent=readdir(proc) )) {
    char tbuf[32];
    char *cp;
    int fd;
    char c;

    if (!isdigit(ent->d_name[0])) continue;
    sprintf(tbuf, "/proc/%s/stat", ent->d_name);

    fd = open(tbuf, O_RDONLY, 0);
    if (fd == -1) continue;
    memset(tbuf, '\0', sizeof tbuf); // didn't feel like checking read()
    read(fd, tbuf, sizeof tbuf - 1); // need 32 byte buffer at most
    close(fd);

    cp = strrchr(tbuf, ')');
    if(!cp) continue;
    c = cp[2];

    if (c=='R') {
      (*running)++;
      continue;
    }
    if (c=='D') {
      (*blocked)++;
      continue;
    }
  }
  closedir(proc);
}