fix infinite while loop when Offline

examples/upload_image/upload_image.ino

@@ -8,7 +8,7 @@ https://github.com/ldab/ESP32_FTPClient
 Distributed as-is; no warranty is given.
 
 ******************************************************************************/
-
+#include "Arduino.h"
 #include <WiFi.h>
 #include <WiFiClient.h> 
 #include <ESP32_FTPClient.h>
@@ -45,19 +45,22 @@ void setup()
   String list[128];
   ftp.ChangeWorkDir("/public_html/zyro/gallery_gen/");
   ftp.ContentList("", list);
-  Serial.print("\nDirectory info: ");
-  Serial.println(list[2]);
-  ftp.CloseFile();
-
+  Serial.println("\nDirectory info: ");
+  for(int i = 0; i < sizeof(list); i++)
+  {
+    if(list[i].length() > 0)
+      Serial.println(list[i]);
+    else
+      break;
+  }
 
   // Make a new directory
   ftp.InitFile("Type A");
-  ftp.MakeDir("/my_new_dir");  
-  ftp.CloseFile();
+  ftp.MakeDir("my_new_dir");
 
   // Create the new file and send the image
+  ftp.ChangeWorkDir("my_new_dir");
   ftp.InitFile("Type I");
-  ftp.ChangeWorkDir("/my_new_dir");
   ftp.NewFile("octocat.jpg");
   ftp.WriteData( octocat_pic, sizeof(octocat_pic) );
   ftp.CloseFile();

src/ESP32_FTPClient.cpp

@@ -1,10 +1,11 @@
 #include <WiFiClient.h>
 #include "ESP32_FTPClient.h"
 
-ESP32_FTPClient::ESP32_FTPClient(char* _serverAdress, char* _userName, char* _passWord){
+ESP32_FTPClient::ESP32_FTPClient(char* _serverAdress, char* _userName, char* _passWord, uint16_t _timeout){
   userName = _userName;
   passWord = _passWord;
   serverAdress = _serverAdress;
+  timeout = _timeout;
 }
 
 WiFiClient* ESP32_FTPClient::GetDataClient() {
@@ -39,7 +40,8 @@ void ESP32_FTPClient::GetFTPAnswer (char* result, int offsetStart) {
   char thisByte;
   outCount = 0;
 
-  while (!client.available()) delay(1);
+  unsigned long _m = millis();
+  while (!client.available() && millis() < _m + timeout) delay(1);
 
   while (client.available()) {
     thisByte = client.read();
@@ -84,7 +86,7 @@ void ESP32_FTPClient::CloseConnection() {
 void ESP32_FTPClient::OpenConnection() {
   Serial.print(F("Connecting to: "));
   Serial.println(serverAdress);
-  if (client.connect(serverAdress, 21)) {  // 21 = FTP server
+  if (client.connect(serverAdress, 21, timeout)) {  // 21 = FTP server
     Serial.println(F("Command connected"));
   } 
   GetFTPAnswer();
@@ -198,8 +200,9 @@ void ESP32_FTPClient::ContentList(const char * dir, String * list) {
   //String resp_string = _resp;
   //resp_string.substring(resp_string.lastIndexOf('matches')-9);
   //Serial.println(resp_string);
-
-  while( !dclient.available() ) delay(1);
+
+  unsigned long _m = millis();
+  while( !dclient.available() && millis() < _m + timeout) delay(1);
 
   while(dclient.available()) 
   {
@@ -221,7 +224,8 @@ void ESP32_FTPClient::DownloadString(const char * filename, String &str) {
   char _resp[ sizeof(outBuf) ];
   GetFTPAnswer(_resp);
 
-  while( !GetDataClient()->available() ) delay(1);
+  unsigned long _m = millis();
+  while( !GetDataClient()->available() && millis() < _m + timeout) delay(1);
 
   while( GetDataClient()->available() )
   {
@@ -240,7 +244,8 @@ void ESP32_FTPClient::DownloadFile(const char * filename, unsigned char * buf, s
 
   char _buf[2];
 
-  while( !dclient.available() ) delay(1);
+  unsigned long _m = millis();
+  while( !dclient.available() && millis() < _m + timeout) delay(1);
 
   while(dclient.available()) 
   {

src/ESP32_FTPClient.h

@@ -11,10 +11,11 @@ class ESP32_FTPClient
   char* serverAdress;
   unsigned char clientBuf[1500];
   size_t bufferSize = 1500;
+  uint16_t timeout = 10000;
   WiFiClient* GetDataClient();
 
   public:
-  ESP32_FTPClient(char* _serverAdress, char* _userName, char* _passWord);
+  ESP32_FTPClient(char* _serverAdress, char* _userName, char* _passWord, uint16_t _timeout = 10000);
   void OpenConnection();
   void CloseConnection();
   void NewFile (const char* fileName);