added useful exception info to ed

app/ed.py

@@ -162,7 +162,7 @@ class Ed:
           sep = params[0]
           parts = params.split(sep)
           if len(parts) < 3:
-            print("?")
+            print("Invalid s/old/new syntax")
             continue
           old, new = parts[1], parts[2]
           start = max(1, start)
@@ -176,7 +176,7 @@ class Ed:
         elif cmd_char == 'w':
           target = params if params else self.filename
           if not target:
-            print("?")
+            print("No target file to write to")
             continue
           with open(target, "w") as f:
             for line in self.buffer:
@@ -191,10 +191,10 @@ class Ed:
           print(self.filename if self.filename else "No current filename")
 
         else:
-          print("?")
+          print("Unknown command")
 
-      except Exception:
-        print("?")
+      except Exception as e:
+        print(f"Exception occurred: {e}")
 
 def edit(fname):
   editor = Ed(fname)