bool  FolderClean(
   string  folder_name,       // String with the name of the deleted folder
   int     common_flag=0      // Scope
   );

//+------------------------------------------------------------------+
//|                                             Demo_FolderClean.mq5 |
//|                        Copyright 2011, MetaQuotes Software Corp. |
//|                                              https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2000-2024, MetaQuotes Ltd."
#property link      "https://www.mql5.com"
#property version   "1.00"
//--- Description
#property description "The script shows a sample use of FolderClean()."
#property description "First, files are created in the specified folder using the FileOpen() function."
#property description "Then, before the files are deleted, a warning is shown using MessageBox()."

//--- Show the dialog of input parameters when starting the script
#property script_show_inputs
//--- Input parameters
input string   foldername="demo_folder";  // Create a folder in MQL4/Files/
input int      files=5;                   // The number of files to create and delete
//+------------------------------------------------------------------+
//| Script program start function                                    |
//+------------------------------------------------------------------+
void OnStart()
  {
   string name="testfile";
//--- First open or create files in the terminal data folder
   for(int N=0;N<files;N++)
     {
      //--- The name of the file in the foem of 'demo_folder\testfileN.txt'
      string filemane=StringFormat("%s\\%s%d.txt",foldername,name,N);
      //--- Open a file with the flag for writing, in this case the 'demo_folder' will be created automatically
      int handle=FileOpen(filemane,FILE_WRITE);
      //--- Find out if the FileOpen() function was successful
      if(handle==INVALID_HANDLE)
        {
         PrintFormat("Failed to create file %s. Error code",filemane,GetLastError());
         ResetLastError();
        }
      else
        {
         PrintFormat("File %s has been successfully opened",filemane);
         //--- The opened file is not needed any more, so close it
         FileClose(handle);
        }
     }

//--- Check the number of files in the folder
   int k=FilesInFolder(foldername+"\\*.*",0);
   PrintFormat("Totally the folder %s contains %d files",foldername,k);

//--- Show a dialog to ask the user
   int choice=MessageBox(StringFormat("You are going to delete %d files from folder %s. Do you want to continue?",foldername,k),
                         "Deleting files from the folder",
                         MB_YESNO|MB_ICONQUESTION); //  Two buttons - "Yes" and "No"
   ResetLastError();

//--- Run an action depending on the selected variant
   if(choice==IDYES)
     {
      //--- Start to delete files
      PrintFormat("Trying to delete all files from folder %s",foldername);
      if(FolderClean(foldername,0))
         PrintFormat("Files have been successfully deleted, %d files left in folder %s",
                     foldername,
                     FilesInFolder(foldername+"\\*.*",0));
      else
         PrintFormat("Failed to delete files from folder %s. Error code %d",foldername,GetLastError());
     }
   else
      PrintFormat("Deletion canceled");
//---
  }
//+------------------------------------------------------------------+
//| Returns the number of files in the specified folder              |
//+------------------------------------------------------------------+
int FilesInFolder(string path,int flag)
  {
   int count=0;
   long handle;
   string filename;
//---
   handle=FileFindFirst(path,filename,flag);
//--- If at least one file found, search for more files
   if(handle!=INVALID_HANDLE)
     {
      //--- Show the name of the file
      PrintFormat("File %s found",filename);
      //--- Increase the counter of found files/folders
      count++;
      //--- Start search in all files/folders
      while(FileFindNext(handle,filename))
        {
         PrintFormat("File %s found",filename);
         count++;
        }
      //--- Do not forget to close the search handle upon completion
      FileFindClose(handle);
     }
   else // Failed to get the handle
     {
      PrintFormat("Files search in folder %s failed",path);
     }
//--- Return the result
   return count;
  }