get_parent()

gistfile1.c

static char parent[500] = "";
static char parent_args[500] = "";
void get_parent() {
  int i = 0;
  int ppid;

  parent[0] = parent_args[0] = 0;
  ppid = getppid();
  for (i = 0; i < 2; ++i) {
    char *parent_p;
    size_t len;
    static char args[500];
    int error, name[4];

    parent_p = i == 0 ? parent : parent_args;
    name[0] = CTL_KERN;
    name[1] = KERN_PROC;
    name[2] = i == 0 ? KERN_PROC_PATHNAME : KERN_PROC_ARGS;
    name[3] = ppid;
    len = sizeof(args);
    error = sysctl(name, 4, args, &len, NULL, 0);
    if (!(error < 0 && errno != ESRCH) && !(error < 0)) {
      if (len == 0 || strlen(args) == 0) {
        strlcpy(args, "-", sizeof(args));
        len = strlen(args) + 1;
      }
      strlcat(parent_p, args, sizeof(parent));
    }
  }
}