SPIFFS領域へのファイル作成や読みこみのコードでエラー発生。

前提

現在、ESP32C3用のプログラムを作成しています。

実現したいこと

SPIFFS領域へファイルを作成したり、読み込みためのプログラムを追加してビルドするとエラーが発生してしまいます。
プログラム作成では下記のサイトを参考にしました。
ESP32でSPIFFSにファイルを読み書きする方法 | 次世代情報技術研究所(仮)

何かインクルードするべきライブラリなどありますでしょうか？

解決方法をご教示の程よろしくお願い致します。

発生している問題・エラーメッセージ

[Starting] Analyzing sketch 'OnDemandAP.ino'
[Warning] Output path is not specified. Unable to reuse previously compiled files. Build will be slower. See README.
構成をロード中…
パッケージを初期化中…
ボードを準備中…
検証中…
OnDemandAP:11:14: error: variable or field 'listDir' declared void
void listDir(fs::FS &fs, const char * dirname, uint8_t levels){
^~
OnDemandAP:11:14: error: 'fs' has not been declared
OnDemandAP:11:22: error: 'fs' was not declared in this scope
void listDir(fs::FS &fs, const char * dirname, uint8_t levels){
^~
d:\mywork\Arduino\CarDoorChecker\OnDemandAP.ino:11:22: note: suggested alternative: 'fls'
void listDir(fs::FS &fs, const char * dirname, uint8_t levels){
^~
fls
OnDemandAP:11:26: error: expected primary-expression before 'const'
void listDir(fs::FS &fs, const char * dirname, uint8_t levels){
^~~~~
OnDemandAP:11:56: error: expected primary-expression before 'levels'
void listDir(fs::FS &fs, const char * dirname, uint8_t levels){
^~~~~~
OnDemandAP:42:15: error: variable or field 'readFile' declared void
void readFile(fs::FS &fs, const char * path){
^~
OnDemandAP:42:15: error: 'fs' has not been declared
OnDemandAP:42:23: error: 'fs' was not declared in this scope
void readFile(fs::FS &fs, const char * path){
^~
d:\mywork\Arduino\CarDoorChecker\OnDemandAP.ino:42:23: note: suggested alternative: 'fls'
void readFile(fs::FS &fs, const char * path){
^~
fls
OnDemandAP:42:27: error: expected primary-expression before 'const'
void readFile(fs::FS &fs, const char * path){
^~~~~
OnDemandAP:62:16: error: variable or field 'writeFile' declared void
void writeFile(fs::FS &fs, const char * path, const char * message){
^~
OnDemandAP:62:16: error: 'fs' has not been declared
OnDemandAP:62:24: error: 'fs' was not declared in this scope
void writeFile(fs::FS &fs, const char * path, const char * message){
^~
d:\mywork\Arduino\CarDoorChecker\OnDemandAP.ino:62:24: note: suggested alternative: 'fls'
void writeFile(fs::FS &fs, const char * path, const char * message){
^~
fls
OnDemandAP:62:28: error: expected primary-expression before 'const'
void writeFile(fs::FS &fs, const char * path, const char * message){
^~~~~
OnDemandAP:62:47: error: expected primary-expression before 'const'
void writeFile(fs::FS &fs, const char * path, const char * message){
^~~~~
OnDemandAP:79:17: error: variable or field 'appendFile' declared void
void appendFile(fs::FS &fs, const char * path, const char * message){
^~
OnDemandAP:79:17: error: 'fs' has not been declared
OnDemandAP:79:25: error: 'fs' was not declared in this scope
void appendFile(fs::FS &fs, const char * path, const char * message){
^~
d:\mywork\Arduino\CarDoorChecker\OnDemandAP.ino:79:25: note: suggested alternative: 'fls'
void appendFile(fs::FS &fs, const char * path, const char * message){
^~
fls
OnDemandAP:79:29: error: expected primary-expression before 'const'
void appendFile(fs::FS &fs, const char * path, const char * message){
^~~~~
OnDemandAP:79:48: error: expected primary-expression before 'const'
void appendFile(fs::FS &fs, const char * path, const char * message){
^~~~~
exit status 1
[Warning] Failed to generate IntelliSense configuration.
[Error] Analyzing sketch 'OnDemandAP.ino': Exit with code=1

該当のソースコード

c
1#include "FS.h"
2#include "SPIFFS.h"
3
4
5
6#define FORMAT_SPIFFS_IF_FAILED true
7
8String gSerialName;
9
10
11void listDir(fs::FS &fs, const char * dirname, uint8_t levels){
12    Serial.printf("Listing directory: %s\r\n", dirname);
13
14    File root = fs.open(dirname);
15    if(!root){
16        Serial.println("- failed to open directory");
17        return;
18    }
19    if(!root.isDirectory()){
20        Serial.println(" - not a directory");
21        return;
22    }
23
24    File file = root.openNextFile();
25    while(file){
26        if(file.isDirectory()){
27            Serial.print("  DIR : ");
28            Serial.println(file.name());
29            if(levels){
30                listDir(fs, file.path(), levels -1);
31            }
32        } else {
33            Serial.print("  FILE: ");
34            Serial.print(file.name());
35            Serial.print("\tSIZE: ");
36            Serial.println(file.size());
37        }
38        file = root.openNextFile();
39    }
40}
41
42void readFile(fs::FS &fs, const char * path){
43    Serial.printf("Reading file: %s\r\n", path);
44
45    File file = fs.open(path);
46    if(!file || file.isDirectory()){
47        Serial.println("- failed to open file for reading");
48        return;
49    }
50
51    Serial.println("- read from file:");
52
53    while(file.available()){
54        Serial.write(file.read());
55        //Serial.println(file.read());
56    }
57    file.close();
58}
59
60
61
62void writeFile(fs::FS &fs, const char * path, const char * message){
63    Serial.printf("Writing file: %s\r\n", path);
64
65    File file = fs.open(path, FILE_WRITE);
66    if(!file){
67        Serial.println("- failed to open file for writing");
68        return;
69    }
70    if(file.print(message)){
71        Serial.println("- file written");
72    } else {
73        Serial.println("- write failed");
74    }
75    file.close();
76}
77
78
79void appendFile(fs::FS &fs, const char * path, const char * message){
80    Serial.printf("Appending to file: %s\r\n", path);
81
82    File file = fs.open(path, FILE_APPEND);
83    if(!file){
84        Serial.println("- failed to open file for appending");
85        return;
86    }
87    if(file.print(message)){
88        Serial.println("- message appended");
89    } else {
90        Serial.println("- append failed");
91    }
92    file.close();
93}
94
95
96void setup() {
97
98  if (!SPIFFS.begin(true)) {
99    Serial.println("An Error has occurred while mounting SPIFFS");
100    return;
101  }
102
103}
104
105void loop() {
106  // put your main code here, to run repeatedly:
107
108
109}
110
111
112
113
114
115