FileWriteInteger

The function writes the value of the int parameter to a bin-file, starting from the current position of the file pointer.

uint  FileWriteInteger(
   int  file_handle,        // File handle
   int  value,              // Value to be written
   int  size=INT_VALUE      // Size in bytes
   );

Parameters

file_handle

[in] File descriptor returned by FileOpen().

value

[in] Integer value.

size=INT_VALUE

[in] Number of bytes (up to 4 inclusive), that should be written. The corresponding constants are provided: CHAR_VALUE=1, SHORT_VALUE=2 and INT_VALUE=4, so the function can write the integer value of char, uchar, short, ushort, int, or uint type.

Return Value

If successful the function returns the number of bytes written or 0 in case of error. If successful, the number of bytes written corresponds to the data type size. To obtain information about the error call the GetLastError() function. The file pointer is shifted by the same number of bytes.

Example:

//+------------------------------------------------------------------+
//|                                        Demo_FileWriteInteger.mq4 |
//|                        Copyright 2014, MetaQuotes Software Corp. |
//|                                              https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2014, MetaQuotes Software Corp."
#property link      "https://www.mql5.com"
#property version   "1.00"
#property strict
//--- show the window of input parameters when launching the script
#property script_show_inputs
//--- parameters for receiving data from the terminal
input string             InpSymbolName="EURUSD";     // Currency pair
input ENUM_TIMEFRAMES    InpSymbolPeriod=PERIOD_H1;  // Time frame
//--- parameters for writing data to the file
input string             InpFileName="Trend.bin";    // File name
input string             InpDirectoryName="Data";    // Folder name
//+------------------------------------------------------------------+
//| Script program start function                                    |
//+------------------------------------------------------------------+
void OnStart()
  {
   double   close_buff[];
   datetime time_buff[];
   int      size;
//--- set indexing as timeseries
   ArraySetAsSeries(close_buff,true);
   ArraySetAsSeries(time_buff,true);
//--- reset the error value
   ResetLastError();
//--- copy the close price for each bar
   if(CopyClose(InpSymbolName,InpSymbolPeriod,0,1000,close_buff)==-1)
     {
      PrintFormat("Failed to copy the values of close prices. Error code = %d",GetLastError());
      return;
     }
//--- copy the time for each bar
   if(CopyTime(InpSymbolName,InpSymbolPeriod,0,1000,time_buff)==-1)
     {
      PrintFormat("Failed to copy time values. Error code = %d",GetLastError());
      return;
     }
//--- get the buffer size
   size=ArraySize(close_buff);
//--- open the file for writing the values (if the file is absent, it will be created automatically)
   ResetLastError();
   int file_handle=FileOpen(InpDirectoryName+"//"+InpFileName,FILE_READ|FILE_WRITE|FILE_BIN);
   if(file_handle!=INVALID_HANDLE)
     {
      PrintFormat("%s file is available for writing",InpFileName);
      PrintFormat("File path: %s\\Files\\",TerminalInfoString(TERMINAL_DATA_PATH));
      //---
      uint  byteswritten;// number of bytes written
      int   up_down=0;   // trend flag
      int   arr_size;    // arr array size
      uchar arr[];       // uchar type array
      //--- write time values to the file
      for(int i=0;i<size-1;i++)
        {
         //--- compare close prices of the current and next bars
         if(close_buff[i]<=close_buff[i+1])
           {
            if(up_down!=1)
              {
               //--- write date value to the file using FileWriteInteger
               StringToCharArray(TimeToString(time_buff[i]),arr);
               arr_size=ArraySize(arr);
               //--- first, write the number of chars in the array
               byteswritten=FileWriteInteger(file_handle,arr_size,INT_VALUE);
               //--- checking the number of bytes written
               if(byteswritten!=sizeof(int))
                 {
                  PrintFormat("Error in FileWriteInteger. Error code=%d",GetLastError());
                  //--- close the file
                  FileClose(file_handle);
                  return;
                 }
               //--- write the chars
               for(int j=0;j<arr_size;j++)
                 {
                  byteswritten=FileWriteInteger(file_handle,arr[j],CHAR_VALUE);
                  //--- checking the number of bytes written
                  if(byteswritten!=sizeof(char))
                    {
                     PrintFormat("Error in FileWriteInteger. Error code=%d",GetLastError());
                     //--- close the file
                     FileClose(file_handle);
                     return;
                    }
                 }
               //--- change the trend flag
               up_down=1;
              }
           }
         else
           {
            if(up_down!=-1)
              {
               //--- write the date value to the file using FileWriteInteger
               StringToCharArray(TimeToString(time_buff[i]),arr);
               arr_size=ArraySize(arr);
               //--- first, write the number of chars in the array
               byteswritten=FileWriteInteger(file_handle,arr_size,INT_VALUE);
               //--- checking the number of bytes written
               if(byteswritten!=sizeof(int))
                 {
                  PrintFormat("Error in FileWriteInteger. Error code=%d",GetLastError());
                  //--- close the file
                  FileClose(file_handle);
                  return;
                 }
               //--- write chars
               for(int j=0;j<arr_size;j++)
                 {
                  byteswritten=FileWriteInteger(file_handle,arr[j],CHAR_VALUE);
                  //--- checking the number of bytes written
                  if(byteswritten!=sizeof(char))
                    {
                     PrintFormat("Error in FileWriteInteger. Error code=%d",GetLastError());
                     //--- close the file
                     FileClose(file_handle);
                     return;
                    }
                 }
               //--- change the trend flag
               up_down=-1;
              }
           }
        }
      //--- close the file
      FileClose(file_handle);
      PrintFormat("Data is written, %s file is closed",InpFileName);
     }
   else
      PrintFormat("Data is written, %s file is closed",InpFileName,GetLastError());
  }