Added invalid file name errors

README.md

@@ -5,9 +5,6 @@
 > [!IMPORTANT]
 > Word is still in development, some functionalities may not work as expected or may be missing. Please report any issues you encounter.
 
-> [!WARNING]
-> There are currently many memory leaks, high memory usage is expected. I'm currently working on them. 
-
 WordLanguage is a programming language designed to minimize the use of symbols, making it easy to read and write. Its syntax is simple and closely resembles natural language, aiming to be both easy to learn and powerful enough for complex programming tasks.
 
 **Key Features**:

src/interpreter.c

@@ -8,6 +8,15 @@ int main(int argc, char *argv[]) {
         return 1;
     }
 
+    if (strlen(argv[1]) < 3) {
+        fprintf(stderr, "Error: Invalid file name\n");
+        return 1;
+    }
+    if (strcmp(argv[1] + strlen(argv[1]) - 2, ".w") != 0) {
+        fprintf(stderr, "Error: Invalid file extension\n");
+        return 1;
+    }
+
     FILE *file;
     if (DEBUG) file = fopen("test.w", "r"); //DEBUG
     else file = fopen(argv[1], "r");