Help with export data

I try this, but the txt of GPBUSD has the same values that the txt of EURUSD:

#property indicator_chart_window
#property indicator_buffers 1
#property indicator_width1 2
#property indicator_color1 Tomato
double ExtMap[];
double ExtMap1[];
extern int       length = 200;

int init()
{
   SetIndexStyle(0, DRAW_LINE);
   SetIndexBuffer(0, ExtMap);
   return(0);
}

int start()
{
   static int rea = 0;
   static int old_bars = 0; 
   static int rea1 = 0;
   static int old_bars1 = 0;
   
   if (old_bars != iBars("EURUSD",PERIOD_M30))
   {
      delete_result();
      clear_graf();
      write_data(); // 
   }
   
   int handle_read = FileOpen("EURUSD"+"_M30"+"_result.csv",FILE_CSV|FILE_READ,';');
   if(handle_read >= 0)
   { 
      Comment("EURUSD"+"_M30" );
      read_n_draw(handle_read);
      delete_result();
      FileClose(handle_read);
      rea=0;
   }
   else 
   {
      rea++;
      Comment("descargar: "+"EURUSD_M30"+"#"+GetLastError()+"#rea"+rea);
      //FileClose(handle_read);
   }
   old_bars = iBars("EURUSD",PERIOD_M30);  // 
   
   if (old_bars != iBars("GPBUSD",PERIOD_M30))
   {
      delete_result1();
      clear_graf1();
      write_data1(); // 
   }
   
   int handle_read1 = FileOpen("GPBUSD"+"_M30"+"_result.csv",FILE_CSV|FILE_READ,';');
   if(handle_read1 >= 0)
   { 
      Comment("GPBUSD"+"_M30" );
      read_n_draw1(handle_read1);
      delete_result1();
      FileClose(handle_read1);
      rea1=0;
   }
   else 
   {
      rea1++;
      Comment("descargar: "+"GPBUSD"+"#"+GetLastError()+"#rea"+rea1);
      //FileClose(handle_read);
   }
   old_bars1 = iBars("GPBUSD",PERIOD_M30);  // 
   
   
   return(0);
   
}
//+------------------------------------------------------------------+
void read_n_draw(int handle_read)
{
   int i=0;
   while ( !FileIsEnding(handle_read) )
   {
      ExtMap[i] = FileReadNumber(handle_read);
      i++;     
      Comment(ExtMap[0]); 
   }
   ExtMap[i-1] = EMPTY_VALUE;
   
}

void read_n_draw1(int handle_read1)
{
   int i=0;
   while ( !FileIsEnding(handle_read1) )
   {
      ExtMap1[i] = FileReadNumber(handle_read1);
      i++;     
      Comment(ExtMap1[0]); 
   }
   ExtMap1[i-1] = EMPTY_VALUE;
   
}


void clear_graf()
{
   ArrayInitialize( ExtMap, EMPTY_VALUE);
   return(0);
}

void clear_graf1()
{
   ArrayInitialize( ExtMap1, EMPTY_VALUE);
   return(0);
}


void delete_result()
{
   
   string filename = "EURUSD"+ "_M30" + "_result.csv";
   FileDelete(filename);
   return(0);
} 
 
void delete_result1()
{
   
   string filename1 = "GPBUSD"+ "_M30" + "_result.csv";
   FileDelete(filename1);
   return(0);
}  
 
 
void write_data()
{
  int handle;
  string EURUSD;
  string _M30;
  string filename =  "EURUSD"+ "_M30"  + ".txt"; // 
  handle = FileOpen(filename,FILE_CSV|FILE_WRITE,';');
  if(handle < 1)
  {
    Print(" #", GetLastError());
    return(0);
    //FileClose(handle);
  }
  
  FileWrite(handle, "DATE","TIME","HIGH","LOW","CLOSE","OPEN","VOLUME"); // 
  int i;
  for (i=length-1; i>=0; i--)
  {
  
  double O,H,L,C, T, V;
  
         O = iOpen (EURUSD, PERIOD_M30, i);
         H = iHigh (EURUSD, PERIOD_M30, i);      
         L = iLow  (EURUSD, PERIOD_M30, i);      
         C = iClose(EURUSD, PERIOD_M30, i); 
         T = iTime (EURUSD, PERIOD_M30, i); 
         V = iVolume (EURUSD, PERIOD_M30, i);
                     
        
         
       
         
    FileWrite(handle, TimeToStr(T, TIME_DATE), TimeToStr(T, TIME_SECONDS),
                      H, L, C, O, V);
  }
  FileClose(handle);
  return(0);
}


void write_data1()
{
  int handle1;
  string GPBUSD;
  string _M30;
  string filename1 =  "GPBUSD"+ "_M30"  + ".txt"; // 
  handle1 = FileOpen(filename1,FILE_CSV|FILE_WRITE,';');
  if(handle1 < 1)
  {
    Print(" 1#", GetLastError());
    return(0);
    //FileClose(handle);
  }
  
  FileWrite(handle1, "DATE","TIME","HIGH","LOW","CLOSE","OPEN","VOLUME"); // 
  int i;
  for (i=length-1; i>=0; i--)
  {
  
  double O1,H1,L1,C1, T1, V1;
  
         O1 = iOpen (GPBUSD, PERIOD_M30, i);
         H1 = iHigh (GPBUSD, PERIOD_M30, i);      
         L1 = iLow  (GPBUSD, PERIOD_M30, i);      
         C1 = iClose(GPBUSD, PERIOD_M30, i); 
         T1 = iTime (GPBUSD, PERIOD_M30, i); 
         V1 = iVolume (GPBUSD, PERIOD_M30, i);
                     
        
         
       
         
    FileWrite(handle1, TimeToStr(T1, TIME_DATE), TimeToStr(T1, TIME_SECONDS),
                      H1, L1, C1, O1, V1);
  }
  FileClose(handle1);
  return(0);
}

 And is very code for two currencies

hello,

Please, make up your program structure first before starting to code things out. For that matter, start with something simple, as e.g. copy all existing bars to a file succesfully.  After, try to do it in multiple pairs; hint - for that you can use as a file handler an array, like filehandle[i]=FileOpen(). Then try to make up your program to handle the situation of having to deal with already existent files (which probably already contain a number of bars) and so on

That way you should be more able to resolve issues as, and if, they are arriving, and you will have a more complete "picture" of how complex your software is going to be 

best regards