esp8266 spiffs check

#include "FS.h"


void setup() {
  Serial.begin(115200);
  Serial.println("SPIFFS begin");
  delay(500);
  SPIFFS.begin();
  Serial.println("Attempting SPIFFS format");
  delay(500);
  if(SPIFFS.format()){
    Serial.println("SPIFFS format was successful.");
  }else{
    Serial.println("ERROR: SPIFFS.format() returned false.");
  }


  FSInfo fs_info;
  SPIFFS.info(fs_info);

  Serial.println("fs_info.totalBytes="+String(fs_info.totalBytes));
  Serial.println("fs_info.usedBytes="+String(fs_info.usedBytes));
  Serial.println("fs_info.blockSize="+String(fs_info.blockSize));
  Serial.println("fs_info.pageSize="+String(fs_info.pageSize));
  Serial.println("fs_info.maxOpenFiles="+String(fs_info.maxOpenFiles));
  Serial.println("fs_info.maxPathLength="+String(fs_info.maxPathLength));
  delay(500);

  Serial.println("ESP.getFreeHeap()=" + String(ESP.getFreeHeap()));
  Serial.println("ESP.getSketchSize()=" + String(ESP.getSketchSize()));
  Serial.println("ESP.getFreeSketchSpace()=" + String(ESP.getFreeSketchSpace()));
  Serial.println("ESP.getFlashChipSize()=" + String(ESP.getFlashChipSize()));
  Serial.println("ESP.getFlashChipRealSize()=" + String(ESP.getFlashChipRealSize()));
  delay(500);

  Serial.println("Opening file for writing");
  delay(500);
  //write
  File f = SPIFFS.open("/test", "w");
  if (!f) {
      Serial.println("file open failed (write)");
  }else{
    Serial.println("File was opened for writing.");
    f.println("Some settings data");
    Serial.println("Wrote \"Some settings data\" into the file.");
  }
  f.close();
  Serial.println("File was closed.");

  Serial.println("Opening file for reading");
  delay(500);

  //read
  f = SPIFFS.open("/test", "r");
  if (!f) {
      Serial.println("file open failed (read)");
  }else{
    Serial.println("File was opened for reading.");
    int file_size = f.size();
    Serial.println("f.size()=" + String(file_size));
    Serial.println("Reading/outputting file content in 1.5s:");
    delay(1500);

    String file_content = "";
    for(int i = 0; i < file_size; i++){
      byte b = f.read();
      Serial.println(String((char)b)+ " - " + String((int)b));
      file_content += (char)b;
    }
  }
  f.close();
  Serial.println("File was closed.");
}

void loop() {

}