help:delete the information from txt

[ayoublaser]

i want to delete the information from txt every tick

how can i do this

[Keith Watford]

What is txt?

[ayoublaser]

it's a file

[William Roeder]

ayoub: it's a file	FileDelete

[ayoublaser]

it not work ,Does not read the new value it read just last value, can you correct this expert, please.

//--- display the window of input parameters when launching the script
//--- input parameters
input string InpFileName="data.bin";
input string InpDirectoryName="SomeFolder";
//+------------------------------------------------------------------+
//| Structure for storing price data                                 |
//+------------------------------------------------------------------+
struct prices
  {
   datetime          date; // date
   double            bid;  // bid price
   double            ask;  // ask price
  };
//+------------------------------------------------------------------+
//| Script program start function                                    |
//+------------------------------------------------------------------+
void OnTick()
  {
//--- structure array
   prices arr[];
//--- file path
   string path=InpDirectoryName+"//"+InpFileName;
//--- open the file
   ResetLastError();
   int file_handle=FileOpen(path,FILE_READ|FILE_BIN);
   if(file_handle!=INVALID_HANDLE)
     {
      //--- read all data from the file to the array
      FileReadArray(file_handle,arr);
      //--- receive the array size
      int size=ArraySize(arr);
      //--- print data from the array
      for(int i=0;i<size;i++)
         Print("Date = ",arr[i].date," Bid = ",arr[i].bid," Ask = ",arr[i].ask);
      Print("Total data = ",size);
      //--- close the file

FileDelete(InpFileName);

      FileClose(file_handle);
     }
   else
      Print("File open failed, error ",GetLastError());
  }

[William Roeder]

ayoub: it not work

1. It does work. You would have found out why had you bothered to check your return codes. What are Function return values ? How do I use them ? - MQL4 forum and Common Errors in MQL4 Programs and How to Avoid Them - MQL4 Articles
   

2.    string path=InpDirectoryName+"//"+InpFileName;
      int file_handle=FileOpen(path,FILE_READ|FILE_BIN);
   
   FileDelete(InpFileName);
   

   Your file name is in path. Why don't you try deleting it?
   

[ayoublaser]

i use that but when start delete it can't read again

the "file find first" , "next" and "close" it Necessary to define the new value and "file is exist"

[William Roeder]

ayoub: i use that but when start delete it can't read again	Make up your mind. If you want to delete the information, you can't read it again.

[Demos Stogios]

From what I can undestand, OP actually wants to empty the contents of the file and not to delete the whole file. So, OP, first FileClose(yourfile); and then FileOpen("filename.bin",FILE_WRITE|FILE_BIN);

To be more clear, I repeat, do not FILE_READ at that time and your file will be emptied

 

best regards 

[JD4]

I think they want to delete specific information from within the file, not the entire file itself.  FileDelete would not be the correct solution to the problem in this case.

[ayoublaser]

I want to offload content the txt after reading the information