拼接字符串

char *firstName =
      "{\"cmd\":\"wifi_config\",\"wifiSsid\":\"jack\",\"wifiPwd\":\"jack.12306\"}";
  char *lastName = "Tsao";
  strcpy(recData, firstName);
  strcat(recData, lastName);
  printf("%s\n", recData);
  printf("%d\n", strlen(recData));

  if (strstr(recData, "}")) {
    printf("%s\n", "包涵");
    recData[0] = '\0';
    printf("%d\n", strlen(recData));
  } else {
    printf("%s\n", "不包涵");
  }