demonstrates the file length issue

SPIFFSfile length issue

#include <ESP8266WiFi.h>
#include <ESP8266WebServer.h>
#include <FS.h>
#include <ArduinoOTA.h>
#include <ESP8266mDNS.h>

const char* ssid = "xxx";
const char* password = "xxx";


void setup ( void ) {
	Serial.begin ( 115200 );
	WiFi.begin ( ssid, password );
	Serial.println ( "" );
	SPIFFS.begin();
	// Wait for connection
	while ( WiFi.status() != WL_CONNECTED ) {
		delay ( 500 );
		Serial.print ( "." );
	}

	Serial.println ( "" );
	Serial.print ( "Connected to " );
	Serial.println ( ssid );
	Serial.print ( "IP address: " );
	Serial.println ( WiFi.localIP() );
    ArduinoOTA.begin();

    ListSPIFFS(); 
    DeleteSPIFFS();
    ListSPIFFS(); 
    String name = String(); 
    File f; 

    for (int i = 4; i < 34; i++) {
    	char buf[3];
    	sprintf(buf, "%02u", i); 
    	name += "a"; 
    	String filename = "/" + String(buf) + name; 
    	Serial.println(filename);
    	f = SPIFFS.open(filename, "w"); 
    	f.println(filename);
    	f.close();
    }

    ListSPIFFS(); 

}

void loop ( void ) {
	ArduinoOTA.handle();

}

void ListSPIFFS() {

Serial.println("SPIFFS FILES:");
    {
    Dir dir = SPIFFS.openDir("/");
    while (dir.next()) {    
      String fileName = dir.fileName();
      size_t fileSize = dir.fileSize();
      Serial.printf("     FS File: %s, size: %s\n", fileName.c_str(), formatBytes(fileSize).c_str());
    }
    Serial.printf("\n");
  }
}

void DeleteSPIFFS() {

Serial.println("Deleting SPIFFS FILES:");
    {
    Dir dir = SPIFFS.openDir("/");
    while (dir.next()) {    
      String fileName = dir.fileName();
      Serial.printf("Deleting File: %s\n", fileName.c_str());
      SPIFFS.remove(fileName); 
    }
    Serial.printf("\n");
  }
}

//format bytes
String formatBytes(size_t bytes){
  if (bytes < 1024){
    return String(bytes)+"B";
  } else if(bytes < (1024 * 1024)){
    return String(bytes/1024.0)+"KB";
  } else if(bytes < (1024 * 1024 * 1024)){
    return String(bytes/1024.0/1024.0)+"MB";
  } else {
    return String(bytes/1024.0/1024.0/1024.0)+"GB";
  }
}