implement the functions ageInput() and showMenu() to execute mainMenu.c .

src/main.c

@@ -1,6 +1,8 @@
-#include <stdio.h>
+#include "mainMenu.h"
 
 int main() {
+
+    ageInput();
     
     return 0;
 }

src/mainMenu.c

@@ -39,4 +39,63 @@ bool checkIfInteger(char* input){
 
     }
 }
+void ageInput(){
 
+    char input[20];
+    char* input_pointer;
+
+    long age;
+
+    printf("\nPlease specify your age : ");
+    scanf("%s",input);
+
+
+    while (true)
+    {
+	age = strtol(input,&input_pointer,10);
+
+        if(checkIfInteger(input) == true && agePermission(age)== true)
+	{
+	    age = strtol(input,&input_pointer,10);
+
+	    printf("Access granted!\n\n\n\n");
+
+	    showMenu();
+
+	    break;
+
+	}
+
+	else if(checkIfInteger(input) == true && agePermission(age)== false) 
+	{
+
+            printf("You should be at least 18 years old to create a bank account!\n");
+
+	    break;
+
+	}
+
+	else
+	{
+	    printf("input invalid! try again!\n");
+
+            scanf("%s",input);
+
+	}
+    
+    }
+
+}
+
+
+void showMenu(){
+
+    printf("\t\t\t\t\t\t\t  Welcome to Bank Manager!");
+    printf("\n\n\n\n\t\t\t\t\t\tPlease select one of the following functions!");
+    printf("\n\n\n\n\t\t\t\t\t\t      ->Login as an existing costumer.");
+    printf("\n\n\t\t\t\t\t\t        ->Register as a new costumer.");
+    printf("\n\n\t\t\t\t\t\t           ->Login as an Employee.");
+    printf("\n\n\t\t\t\t\t\t\t\t ->Exit.\n");
+    printf("\n\n\n\n\n Selection :\n");
+
+}

src/mainMenu.h

@@ -9,5 +9,8 @@
 bool agePermission(int age);
 bool checkIfInteger(char* userInput);
 
+void ageInput();
+void showMenu();
+
 #endif