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MQL5 ReferenceFile FunctionsFileWriteInteger 

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. The file pointer is shifted by the same number of bytes.

Example:

//+------------------------------------------------------------------+
//|                                        Demo_FileWriteInteger.mq5 |
//|                        Copyright 2013, MetaQuotes Software Corp. |
//|                                              https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2013, MetaQuotes Software Corp."
#property link      "https://www.mql5.com"
#property version   "1.00"
//--- 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
input datetime           InpDateStart=D'2013.01.01 00:00'; // data copying start date
//--- parameters for writing data to the file
input string             InpFileName="Trend.bin"// file name
input string             InpDirectoryName="Data"// directory name
//+------------------------------------------------------------------+
//| Script program start function                                    |
//+------------------------------------------------------------------+
void OnStart()
  {
   datetime date_finish=TimeCurrent();
   double   close_buff[];
   datetime time_buff[];
   int      size;
//--- reset the error value
   ResetLastError();
//--- copy the close price for each bar
   if(CopyClose(InpSymbolName,InpSymbolPeriod,InpDateStart,date_finish,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,InpDateStart,date_finish,time_buff)==-1)
     {
      PrintFormat("Failed to copy time values. Error code = %d",GetLastError());
      return;
     }
//--- receive 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));
      //--- 
      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 symbols in the array
               FileWriteInteger(file_handle,arr_size,INT_VALUE);
               //--- write the symbols
               for(int j=0;j<arr_size;j++)
                  FileWriteInteger(file_handle,arr[j],CHAR_VALUE);
               //--- 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 symbols in the array
               FileWriteInteger(file_handle,arr_size,INT_VALUE);
               //--- write the symbols
               for(int j=0;j<arr_size;j++)
                  FileWriteInteger(file_handle,arr[j],CHAR_VALUE);
               //--- change the trend flag
               up_down=-1;
              }
           }
        }
      //--- close the file
      FileClose(file_handle);
      PrintFormat("Data is written, %s file is closed",InpFileName);
     }
   else
      PrintFormat("Failed to open %s file, Error code = %d",InpFileName,GetLastError());
  }

See also

IntegerToString, StringToInteger, Integer types


Updated: 2015.12.03