Create file with function getAvailableAccountBalance

src/currentCustomerAccountBalance.c

@@ -0,0 +1,45 @@
+#include "currentCustomerAccountBalance.h"
+
+float getAvailableAccountBalance(int user_id) {
+    bool keep_reading = true;
+    float balance = 0;
+
+    char buffer[MAX_LENGTH];
+    char stringID[MAX_LENGTH] = "ID=";
+    char user_id_as_string[MAX_LENGTH];
+    char balance_String[MAX_LENGTH];
+
+    sprintf(user_id_as_string, "%d", user_id);
+    strcat(stringID, user_id_as_string);
+
+    FILE *file = fopen("CustomerData.txt", "r"); 
+
+    while(keep_reading) {
+        fgets(buffer, MAX_LENGTH, file);
+        if (feof(file)) {
+            keep_reading = false;
+        }
+        else if(strstr(buffer, stringID)) {
+            fgets(buffer, MAX_LENGTH, file);
+            fgets(buffer, MAX_LENGTH, file);
+            fgets(buffer, MAX_LENGTH, file);
+            fgets(buffer, MAX_LENGTH, file);
+            strcpy(balance_String, buffer);
+
+            char *token = strtok(balance_String, "=");
+            while (token != NULL) {
+                if (atoi(token) != 0) {
+                    balance = atof(token);
+                    break;
+                }
+                token = strtok(NULL, "=");
+            }
+            keep_reading = false;
+        }
+
+    }
+    fclose(file);
+    
+    return balance;
+    
+}