Fixes according to review

Author: eyuell21

implement-shell-tools/cat/my_cat.py

@@ -14,17 +14,35 @@
 number_nonblank = args.number_nonblank
 number_all = args.number and not number_nonblank
 
+
+total_lines = 0
+total_nonblank_lines = 0
+
+for path in file_paths:
+    try:
+        with open(path, 'r', encoding='utf-8') as f:
+            lines = f.readlines()
+            total_lines += len(lines)
+            total_nonblank_lines += sum(1 for line in lines if line.strip())
+    except Exception as e:
+        print(f'Error reading file "{path}": {e}', file=sys.stderr)
+        sys.exit(1)
+
+
+if number_nonblank:
+    max_digits = len(str(total_nonblank_lines))
+elif number_all:
+    max_digits = len(str(total_lines))
+
 line_number = 1
 
+
 for path in file_paths:
     try:
         with open(path, 'r', encoding='utf-8') as f:
             lines = f.readlines()
 
         if number_nonblank:
-            nonblank_lines = [line for line in lines if line.strip()]
-            max_digits = len(str(len(nonblank_lines)))
-
             for line in lines:
                 if line.strip() == "":
                     print()
@@ -34,8 +52,6 @@
                     line_number += 1
 
         elif number_all:
-            max_digits = len(str(len(lines) * len(file_paths)))
-
             for line in lines:
                 num_str = str(line_number).rjust(max_digits)
                 print(f"{num_str}\t{line.rstrip()}")
@@ -44,7 +60,7 @@
         else:
             for line in lines:
                 print(line, end='')
-            if not lines[-1].endswith('\n'):
+            if lines and not lines[-1].endswith('\n'):
                 print()
 
     except Exception as e: