Arduino File.openNextFile()

Description

The File.openNextFile() function opens the next file or folder in a directory.

Syntax

file.openNextFile()

Parameters

  • file: an instance of the File class that is a directory

Returns

  • A File object referring to the next file or folder in the path. if there is no next file or folder, this object will evaluate to false in a boolean context.

Example Code

/* * Created by ArduinoGetStarted.com * * This example code is in the public domain * * Tutorial page: https://arduinogetstarted.com/reference/library/arduino-file.opennextfile */ #include <SD.h> #define PIN_SPI_CS 4 File root; void setup() { Serial.begin(9600); if (!SD.begin(PIN_SPI_CS)) { Serial.println("SD CARD FAILED, OR NOT PRESENT!"); while (1); // don't do anything more: } root = SD.open("/"); printDirectory(root, 0); root.close(); } void loop() { // nothing happens after setup finishes. } void printDirectory(File dir, int numTabs) { while (true) { File entry = dir.openNextFile(); if (!entry) { if (numTabs == 0) Serial.println("** Done **"); return; } for (uint8_t i = 0; i < numTabs; i++) { Serial.print('\t'); } Serial.print(entry.name()); if (entry.isDirectory()) { Serial.println("/"); printDirectory(entry, numTabs + 1); } else { Serial.print("\t\t"); Serial.println(entry.size(), DEC); } entry.close(); } }

ARDUINO BUY RECOMMENDATION

Arduino UNO R3
Arduino Starter Kit
Please note: These are Amazon affiliate links. If you buy the components through these links, We will get a commission at no extra cost to you. We appreciate it.

※ OUR MESSAGES