MQL4/.github/instructions/mql4-scripts.instructions.md

applyTo
**/MQL4/Scripts/_Thivyam/**/*.mq4

Instructions for _Thivyam MQL4 Scripts

CRITICAL: MQL4 Syntax Compliance

Before writing any MQL4 code, read and follow: mql4-syntax-critical.instructions.md

Key mandatory rules for scripts:

• Declare loop variables BEFORE for-loop: int i; for(i=0; i<n; i++)
• Use GetLastError() after all trade operations
• Normalize all prices and lot sizes
• Scripts execute once and terminate (no OnTick)

---

Script Overview

MQL4 Scripts are programs that execute a specific task once and then terminate. They are ideal for:

• Batch operations (closing all orders, deleting all objects)
• One-time calculations or analysis
• Chart setup automation
• Trade management utilities
• Data export/import operations

Key Differences from EAs:

• Scripts use OnStart() instead of OnTick()
• Execute once and terminate
• No continuous monitoring
• Perfect for utility functions

---

Script Structure

Basic Template

//+------------------------------------------------------------------+
//|                                              YourScript.mq4      |
//|                                            Author: Your Name     |
//|                                     https://www.yourwebsite.com  |
//+------------------------------------------------------------------+
#property copyright "Your Name"
#property link      "https://www.yourwebsite.com"
#property version   "1.00"
#property strict
#property description "Brief description of script function"
#property show_inputs  // Show input dialog before execution

// INPUT PARAMETERS
input int    InpMagicNumber = 123456;  // Magic Number
input bool   InpConfirm = true;        // Ask for confirmation

//+------------------------------------------------------------------+
//| Script program start function                                    |
//+------------------------------------------------------------------+
void OnStart()
{
   // 1. Validate inputs
   if(InpMagicNumber == 0)
   {
      Print("Warning: Magic number is 0");
   }
   
   // 2. Ask for confirmation if enabled
   if(InpConfirm)
   {
      int result = MessageBox("Execute script on " + Symbol() + "?",
                              "Confirm Action",
                              MB_YESNO | MB_ICONQUESTION);
      if(result != IDYES)
      {
         Print("Script execution cancelled by user");
         return;
      }
   }
   
   // 3. Execute main logic
   ExecuteScriptLogic();
   
   // 4. Report results
   Print("Script execution completed successfully");
}

void ExecuteScriptLogic()
{
   // Main script functionality here
}

---

Common Script Types

1. Close All Orders Script

#property show_inputs

input int InpMagicNumber = 0;  // Magic Number (0 = all)
input bool InpConfirm = true;  // Ask confirmation

void OnStart()
{
   int totalClosed = 0;
   int totalFailed = 0;
   
   // Count orders first
   int totalOrders = CountOrders(InpMagicNumber);
   
   if(totalOrders == 0)
   {
      Print("No orders to close");
      return;
   }
   
   // Ask confirmation
   if(InpConfirm)
   {
      string message = "Close " + IntegerToString(totalOrders) + " orders";
      if(InpMagicNumber > 0)
         message += " with Magic Number " + IntegerToString(InpMagicNumber);
      message += "?";
      
      int result = MessageBox(message, "Confirm Close All", MB_YESNO | MB_ICONWARNING);
      if(result != IDYES)
      {
         Print("Operation cancelled");
         return;
      }
   }
   
   // Close all orders (iterate backwards)
   int total = OrdersTotal();
   int i;
   for(i = total - 1; i >= 0; i--)
   {
      if(!OrderSelect(i, SELECT_BY_POS, MODE_TRADES)) continue;
      
      // Filter by symbol
      if(OrderSymbol() != Symbol()) continue;
      
      // Filter by magic number
      if(InpMagicNumber > 0 && OrderMagicNumber() != InpMagicNumber) continue;
      
      bool closed = false;
      int ticket = OrderTicket();
      
      if(OrderType() == OP_BUY)
      {
         closed = OrderClose(ticket, OrderLots(), Bid, 3, clrRed);
      }
      else if(OrderType() == OP_SELL)
      {
         closed = OrderClose(ticket, OrderLots(), Ask, 3, clrRed);
      }
      else  // Pending orders
      {
         closed = OrderDelete(ticket, clrRed);
      }
      
      if(closed)
      {
         totalClosed++;
         Print("Closed ticket #", ticket);
      }
      else
      {
         totalFailed++;
         int error = GetLastError();
         Print("Failed to close ticket #", ticket, " Error: ", error);
      }
   }
   
   // Report results
   string message = "Closed: " + IntegerToString(totalClosed);
   if(totalFailed > 0)
      message += " | Failed: " + IntegerToString(totalFailed);
   
   Print(message);
   MessageBox(message, "Close All Complete", MB_OK | MB_ICONINFORMATION);
}

int CountOrders(int magicNumber)
{
   int count = 0;
   int total = OrdersTotal();
   int i;
   
   for(i = 0; i < total; i++)
   {
      if(!OrderSelect(i, SELECT_BY_POS, MODE_TRADES)) continue;
      if(OrderSymbol() != Symbol()) continue;
      if(magicNumber > 0 && OrderMagicNumber() != magicNumber) continue;
      count++;
   }
   
   return count;
}

---

2. Delete All Objects Script

#property show_inputs

input bool InpConfirm = true;          // Ask confirmation
input string InpPrefix = "";           // Object prefix (empty = all)

void OnStart()
{
   int totalDeleted = 0;
   
   // Count objects
   int totalObjects = ObjectsTotal(0);
   
   if(totalObjects == 0)
   {
      Print("No objects to delete");
      return;
   }
   
   // Ask confirmation
   if(InpConfirm)
   {
      string message = "Delete " + IntegerToString(totalObjects) + " chart objects";
      if(InpPrefix != "")
         message += " with prefix '" + InpPrefix + "'";
      message += "?";
      
      int result = MessageBox(message, "Confirm Delete All", MB_YESNO | MB_ICONWARNING);
      if(result != IDYES)
      {
         Print("Operation cancelled");
         return;
      }
   }
   
   // Delete all objects (iterate backwards)
   int i;
   for(i = totalObjects - 1; i >= 0; i--)
   {
      string objName = ObjectName(0, i);
      
      // Filter by prefix if specified
      if(InpPrefix != "")
      {
         if(StringFind(objName, InpPrefix) != 0) continue;
      }
      
      if(ObjectDelete(0, objName))
      {
         totalDeleted++;
      }
   }
   
   // Redraw chart
   ChartRedraw(0);
   
   Print("Deleted ", totalDeleted, " objects");
   MessageBox("Deleted " + IntegerToString(totalDeleted) + " objects",
              "Delete Complete",
              MB_OK | MB_ICONINFORMATION);
}

---

3. Modify All Orders Script

#property show_inputs

input int InpMagicNumber = 0;        // Magic Number (0 = all)
input int InpNewStopLossPips = 0;    // New SL in pips (0 = no change)
input int InpNewTakeProfitPips = 0;  // New TP in pips (0 = no change)
input bool InpConfirm = true;        // Ask confirmation

void OnStart()
{
   if(InpNewStopLossPips == 0 && InpNewTakeProfitPips == 0)
   {
      Print("ERROR: No modification specified");
      MessageBox("Please specify SL or TP modification", "Error", MB_OK | MB_ICONERROR);
      return;
   }
   
   int totalModified = 0;
   int totalFailed = 0;
   
   // Count orders
   int totalOrders = CountOrders(InpMagicNumber);
   
   if(totalOrders == 0)
   {
      Print("No orders to modify");
      return;
   }
   
   // Ask confirmation
   if(InpConfirm)
   {
      string message = "Modify " + IntegerToString(totalOrders) + " orders?";
      if(InpNewStopLossPips > 0)
         message += "\nNew SL: " + IntegerToString(InpNewStopLossPips) + " pips";
      if(InpNewTakeProfitPips > 0)
         message += "\nNew TP: " + IntegerToString(InpNewTakeProfitPips) + " pips";
      
      int result = MessageBox(message, "Confirm Modify All", MB_YESNO | MB_ICONQUESTION);
      if(result != IDYES)
      {
         Print("Operation cancelled");
         return;
      }
   }
   
   // Modify all orders
   int total = OrdersTotal();
   int i;
   for(i = 0; i < total; i++)
   {
      if(!OrderSelect(i, SELECT_BY_POS, MODE_TRADES)) continue;
      if(OrderSymbol() != Symbol()) continue;
      if(InpMagicNumber > 0 && OrderMagicNumber() != InpMagicNumber) continue;
      
      // Only modify market positions
      if(OrderType() != OP_BUY && OrderType() != OP_SELL) continue;
      
      int ticket = OrderTicket();
      double openPrice = OrderOpenPrice();
      double newSL = OrderStopLoss();
      double newTP = OrderTakeProfit();
      
      // Calculate new SL
      if(InpNewStopLossPips > 0)
      {
         if(OrderType() == OP_BUY)
            newSL = openPrice - InpNewStopLossPips * Point * 10;
         else
            newSL = openPrice + InpNewStopLossPips * Point * 10;
         
         newSL = NormalizeDouble(newSL, Digits);
      }
      
      // Calculate new TP
      if(InpNewTakeProfitPips > 0)
      {
         if(OrderType() == OP_BUY)
            newTP = openPrice + InpNewTakeProfitPips * Point * 10;
         else
            newTP = openPrice - InpNewTakeProfitPips * Point * 10;
         
         newTP = NormalizeDouble(newTP, Digits);
      }
      
      // Modify order
      bool modified = OrderModify(ticket, openPrice, newSL, newTP, 0, clrBlue);
      
      if(modified)
      {
         totalModified++;
         Print("Modified ticket #", ticket, " SL: ", newSL, " TP: ", newTP);
      }
      else
      {
         totalFailed++;
         int error = GetLastError();
         Print("Failed to modify ticket #", ticket, " Error: ", error);
      }
   }
   
   // Report results
   string message = "Modified: " + IntegerToString(totalModified);
   if(totalFailed > 0)
      message += " | Failed: " + IntegerToString(totalFailed);
   
   Print(message);
   MessageBox(message, "Modify Complete", MB_OK | MB_ICONINFORMATION);
}

int CountOrders(int magicNumber)
{
   int count = 0;
   int total = OrdersTotal();
   int i;
   
   for(i = 0; i < total; i++)
   {
      if(!OrderSelect(i, SELECT_BY_POS, MODE_TRADES)) continue;
      if(OrderSymbol() != Symbol()) continue;
      if(magicNumber > 0 && OrderMagicNumber() != magicNumber) continue;
      if(OrderType() != OP_BUY && OrderType() != OP_SELL) continue;
      count++;
   }
   
   return count;
}

---

4. Account Information Script

void OnStart()
{
   string info = "";
   
   info += "========================================\n";
   info += "ACCOUNT INFORMATION\n";
   info += "========================================\n\n";
   
   info += "Account Number: " + IntegerToString(AccountNumber()) + "\n";
   info += "Account Name: " + AccountName() + "\n";
   info += "Account Server: " + AccountServer() + "\n";
   info += "Account Company: " + AccountCompany() + "\n";
   info += "Account Currency: " + AccountCurrency() + "\n";
   info += "Account Leverage: 1:" + IntegerToString(AccountLeverage()) + "\n\n";
   
   info += "Balance: " + DoubleToString(AccountBalance(), 2) + "\n";
   info += "Equity: " + DoubleToString(AccountEquity(), 2) + "\n";
   info += "Margin: " + DoubleToString(AccountMargin(), 2) + "\n";
   info += "Free Margin: " + DoubleToString(AccountFreeMargin(), 2) + "\n";
   info += "Margin Level: " + DoubleToString(AccountMargin() > 0 ? (AccountEquity() / AccountMargin() * 100) : 0, 2) + "%\n\n";
   
   info += "Profit: " + DoubleToString(AccountProfit(), 2) + "\n";
   info += "Credit: " + DoubleToString(AccountCredit(), 2) + "\n\n";
   
   info += "Open Positions: " + IntegerToString(CountOpenPositions()) + "\n";
   info += "Pending Orders: " + IntegerToString(CountPendingOrders()) + "\n";
   
   info += "========================================\n";
   
   // Print to journal
   Print(info);
   
   // Create file
   int handle = FileOpen("AccountInfo_" + TimeToString(TimeCurrent(), TIME_DATE) + ".txt",
                         FILE_WRITE | FILE_TXT);
   if(handle != INVALID_HANDLE)
   {
      FileWriteString(handle, info);
      FileClose(handle);
      Print("Account info saved to file");
   }
   
   // Show message
   MessageBox(info, "Account Information", MB_OK | MB_ICONINFORMATION);
}

int CountOpenPositions()
{
   int count = 0;
   int total = OrdersTotal();
   int i;
   
   for(i = 0; i < total; i++)
   {
      if(!OrderSelect(i, SELECT_BY_POS, MODE_TRADES)) continue;
      if(OrderType() == OP_BUY || OrderType() == OP_SELL) count++;
   }
   
   return count;
}

int CountPendingOrders()
{
   int count = 0;
   int total = OrdersTotal();
   int i;
   
   for(i = 0; i < total; i++)
   {
      if(!OrderSelect(i, SELECT_BY_POS, MODE_TRADES)) continue;
      if(OrderType() > OP_SELL) count++;  // Pending orders
   }
   
   return count;
}

---

5. Draw Support/Resistance Lines Script

#property show_inputs

input int InpLookbackBars = 100;     // Bars to analyze
input int InpMinTouches = 2;         // Minimum touches
input color InpSupportColor = clrGreen;
input color InpResistanceColor = clrRed;

void OnStart()
{
   // Delete old lines
   DeleteOldLines();
   
   // Find support/resistance levels
   double support[], resistance[];
   FindLevels(support, resistance);
   
   // Draw support lines
   int i;
   for(i = 0; i < ArraySize(support); i++)
   {
      DrawHLine("Support_" + IntegerToString(i), support[i], InpSupportColor, STYLE_SOLID);
   }
   
   // Draw resistance lines
   for(i = 0; i < ArraySize(resistance); i++)
   {
      DrawHLine("Resistance_" + IntegerToString(i), resistance[i], InpResistanceColor, STYLE_SOLID);
   }
   
   ChartRedraw(0);
   
   Print("Drew ", ArraySize(support), " support and ", ArraySize(resistance), " resistance lines");
}

void FindLevels(double &support[], double &resistance[])
{
   // Simplified logic - find swing highs/lows
   ArrayResize(support, 0);
   ArrayResize(resistance, 0);
   
   int i;
   for(i = 2; i < InpLookbackBars - 2; i++)
   {
      // Check for swing high (resistance)
      if(iHigh(Symbol(), PERIOD_CURRENT, i) > iHigh(Symbol(), PERIOD_CURRENT, i-1) &&
         iHigh(Symbol(), PERIOD_CURRENT, i) > iHigh(Symbol(), PERIOD_CURRENT, i-2) &&
         iHigh(Symbol(), PERIOD_CURRENT, i) > iHigh(Symbol(), PERIOD_CURRENT, i+1) &&
         iHigh(Symbol(), PERIOD_CURRENT, i) > iHigh(Symbol(), PERIOD_CURRENT, i+2))
      {
         double level = iHigh(Symbol(), PERIOD_CURRENT, i);
         AddLevel(resistance, level);
      }
      
      // Check for swing low (support)
      if(iLow(Symbol(), PERIOD_CURRENT, i) < iLow(Symbol(), PERIOD_CURRENT, i-1) &&
         iLow(Symbol(), PERIOD_CURRENT, i) < iLow(Symbol(), PERIOD_CURRENT, i-2) &&
         iLow(Symbol(), PERIOD_CURRENT, i) < iLow(Symbol(), PERIOD_CURRENT, i+1) &&
         iLow(Symbol(), PERIOD_CURRENT, i) < iLow(Symbol(), PERIOD_CURRENT, i+2))
      {
         double level = iLow(Symbol(), PERIOD_CURRENT, i);
         AddLevel(support, level);
      }
   }
}

void AddLevel(double &levels[], double price)
{
   int size = ArraySize(levels);
   ArrayResize(levels, size + 1);
   levels[size] = NormalizeDouble(price, Digits);
}

void DrawHLine(string name, double price, color lineColor, int style)
{
   ObjectDelete(0, name);
   ObjectCreate(0, name, OBJ_HLINE, 0, 0, price);
   ObjectSetInteger(0, name, OBJPROP_COLOR, lineColor);
   ObjectSetInteger(0, name, OBJPROP_STYLE, style);
   ObjectSetInteger(0, name, OBJPROP_WIDTH, 2);
   ObjectSetInteger(0, name, OBJPROP_SELECTABLE, true);
}

void DeleteOldLines()
{
   int total = ObjectsTotal(0);
   int i;
   
   for(i = total - 1; i >= 0; i--)
   {
      string name = ObjectName(0, i);
      if(StringFind(name, "Support_") == 0 || StringFind(name, "Resistance_") == 0)
      {
         ObjectDelete(0, name);
      }
   }
}

---

Best Practices for Scripts

1. User Confirmation

Always ask for confirmation before destructive operations:

if(InpConfirm)
{
   int result = MessageBox("Are you sure?", "Confirm", MB_YESNO | MB_ICONWARNING);
   if(result != IDYES) return;
}

2. Progress Reporting

Report progress for long operations:

int total = 1000;
int i;
for(i = 0; i < total; i++)
{
   if(i % 100 == 0)
   {
      Comment("Processing: ", (i * 100 / total), "%");
   }
   // Process...
}
Comment("");  // Clear comment

3. Error Handling

Handle errors gracefully:

bool success = OrderClose(ticket, lots, price, slippage);
if(!success)
{
   int error = GetLastError();
   Print("Error closing order: ", error, " - ", ErrorDescription(error));
   // Continue or abort?
}

4. File Operations

Save results to files when appropriate:

int handle = FileOpen("results.csv", FILE_WRITE | FILE_CSV);
if(handle != INVALID_HANDLE)
{
   FileWrite(handle, "Date", "Value");
   // Write data...
   FileClose(handle);
   Print("Results saved to files folder");
}

---

Summary: MQL4 Script Best Practices

1. ✅ Use OnStart() function (executes once)
2. ✅ Set #property show_inputs to show input dialog
3. ✅ Ask confirmation for destructive operations
4. ✅ Report progress for long operations
5. ✅ Handle errors with GetLastError()
6. ✅ Provide clear feedback to user (MessageBox, Print)
7. ✅ Clean up resources (close files, etc.)
8. ✅ Test thoroughly before deployment
9. ✅ Document script functionality clearly
10. ✅ Follow MQL4 syntax rules from critical instructions

Scripts are powerful utilities for traders - make them user-friendly and safe!