char buf[32];

void setup() {
  Serial.begin(115200);
  memset(buf, '\0', sizeof(buf));
  strcpy(buf, "hello world");
  Serial.println(buf);

  char *ptr = strstr( buf, " world");
  if (ptr) 
    Serial.println("TRUE!");
    //value = atoi ( &ptr[14] );

  ptr = strstr( buf, "hello");
  if (ptr) 
    Serial.println("TRUE!");
    //value = atoi ( &ptr[14] );

}

void loop() {
  // put your main code here, to run repeatedly:

}