Add sample for Time date for FatFS like SPIFFS (#3234)

libraries/FFat/examples/FFat_time/FFat_time.ino

@@ -0,0 +1,177 @@
+#include "FS.h"
+#include "FFat.h"
+#include <time.h> 
+#include <WiFi.h>
+
+const char* ssid     = "your-ssid";
+const char* password = "your-password";
+
+long timezone = 1; 
+byte daysavetime = 1;
+
+void listDir(fs::FS &fs, const char * dirname, uint8_t levels){
+    Serial.printf("Listing directory: %s\n", dirname);
+
+    File root = fs.open(dirname);
+    if(!root){
+        Serial.println("Failed to open directory");
+        return;
+    }
+    if(!root.isDirectory()){
+        Serial.println("Not a directory");
+        return;
+    }
+
+    File file = root.openNextFile();
+    while(file){
+        if(file.isDirectory()){
+            Serial.print("  DIR : ");
+            Serial.print (file.name());
+            time_t t= file.getLastWrite();
+            struct tm * tmstruct = localtime(&t);
+            Serial.printf("  LAST WRITE: %d-%02d-%02d %02d:%02d:%02d\n",(tmstruct->tm_year)+1900,( tmstruct->tm_mon)+1, tmstruct->tm_mday,tmstruct->tm_hour , tmstruct->tm_min, tmstruct->tm_sec);
+            if(levels){
+                listDir(fs, file.name(), levels -1);
+            }
+        } else {
+            Serial.print("  FILE: ");
+            Serial.print(file.name());
+            Serial.print("  SIZE: ");
+            Serial.print(file.size());
+            time_t t= file.getLastWrite();
+            struct tm * tmstruct = localtime(&t);
+            Serial.printf("  LAST WRITE: %d-%02d-%02d %02d:%02d:%02d\n",(tmstruct->tm_year)+1900,( tmstruct->tm_mon)+1, tmstruct->tm_mday,tmstruct->tm_hour , tmstruct->tm_min, tmstruct->tm_sec);
+        }
+        file = root.openNextFile();
+    }
+}
+
+void createDir(fs::FS &fs, const char * path){
+    Serial.printf("Creating Dir: %s\n", path);
+    if(fs.mkdir(path)){
+        Serial.println("Dir created");
+    } else {
+        Serial.println("mkdir failed");
+    }
+}
+
+void removeDir(fs::FS &fs, const char * path){
+    Serial.printf("Removing Dir: %s\n", path);
+    if(fs.rmdir(path)){
+        Serial.println("Dir removed");
+    } else {
+        Serial.println("rmdir failed");
+    }
+}
+
+void readFile(fs::FS &fs, const char * path){
+    Serial.printf("Reading file: %s\n", path);
+
+    File file = fs.open(path);
+    if(!file){
+        Serial.println("Failed to open file for reading");
+        return;
+    }
+
+    Serial.print("Read from file: ");
+    while(file.available()){
+        Serial.write(file.read());
+    }
+    file.close();
+}
+
+void writeFile(fs::FS &fs, const char * path, const char * message){
+    Serial.printf("Writing file: %s\n", path);
+
+    File file = fs.open(path, FILE_WRITE);
+    if(!file){
+        Serial.println("Failed to open file for writing");
+        return;
+    }
+    if(file.print(message)){
+        Serial.println("File written");
+    } else {
+        Serial.println("Write failed");
+    }
+    file.close();
+}
+
+void appendFile(fs::FS &fs, const char * path, const char * message){
+    Serial.printf("Appending to file: %s\n", path);
+
+    File file = fs.open(path, FILE_APPEND);
+    if(!file){
+        Serial.println("Failed to open file for appending");
+        return;
+    }
+    if(file.print(message)){
+        Serial.println("Message appended");
+    } else {
+        Serial.println("Append failed");
+    }
+    file.close();
+}
+
+void renameFile(fs::FS &fs, const char * path1, const char * path2){
+    Serial.printf("Renaming file %s to %s\n", path1, path2);
+    if (fs.rename(path1, path2)) {
+        Serial.println("File renamed");
+    } else {
+        Serial.println("Rename failed");
+    }
+}
+
+void deleteFile(fs::FS &fs, const char * path){
+    Serial.printf("Deleting file: %s\n", path);
+    if(fs.remove(path)){
+        Serial.println("File deleted");
+    } else {
+        Serial.println("Delete failed");
+    }
+}
+
+void setup(){
+    Serial.begin(115200);
+    // We start by connecting to a WiFi network
+    Serial.println();
+    Serial.println();
+    Serial.print("Connecting to ");
+    Serial.println(ssid);
+
+    WiFi.begin(ssid, password);
+
+    while (WiFi.status() != WL_CONNECTED) {
+        delay(500);
+        Serial.print(".");
+    }
+    Serial.println("WiFi connected");
+    Serial.println("IP address: ");
+    Serial.println(WiFi.localIP());
+    Serial.println("Contacting Time Server");
+	configTime(3600*timezone, daysavetime*3600, "time.nist.gov", "0.pool.ntp.org", "1.pool.ntp.org");
+	struct tm tmstruct ;
+    delay(2000);
+    tmstruct.tm_year = 0;
+    getLocalTime(&tmstruct, 5000);
+	Serial.printf("\nNow is : %d-%02d-%02d %02d:%02d:%02d\n",(tmstruct.tm_year)+1900,( tmstruct.tm_mon)+1, tmstruct.tm_mday,tmstruct.tm_hour , tmstruct.tm_min, tmstruct.tm_sec);
+    Serial.println("");
+    
+    if(!FFat.begin(true)){
+        Serial.println("FFat Mount Failed");
+        return;
+    }
+
+    listDir(FFat, "/", 0);
+    removeDir(FFat, "/mydir");
+    createDir(FFat, "/mydir");
+    deleteFile(FFat, "/hello.txt");
+    writeFile(FFat, "/hello.txt", "Hello ");
+    appendFile(FFat, "/hello.txt", "World!\n");
+	listDir(FFat, "/", 0);
+}
+
+void loop(){
+
+}
+
+