Enhance ls function with error handling and formatting

Added error handling for file access issues and improved output formatting.

Author: Luke-Manyamazi

implement-shell-tools/ls/ls.py

@@ -1,30 +1,46 @@
 import os
+import sys
 import argparse
 
 def ls(path, one_column, show_hidden):
     """List files in a directory, optionally in one column or including hidden files."""
     try:
+        if os.path.isfile(path):
+            print(os.path.basename(path))
+            return
+
         files = os.listdir(path)
-        if not show_hidden:
+
+        if show_hidden:
+            files = ['.', '..'] + files
+        else:
             files = [f for f in files if not f.startswith('.')]
+
         files.sort()
-        
+
         if one_column:
             print(*files, sep='\n')
         else:
             print(*files)
+
     except FileNotFoundError:
-        print(f"ls: cannot access '{path}': No such file or directory")
+        print(
+            f"ls: cannot access '{path}': No such file or directory",
+            file=sys.stderr
+        )
     except NotADirectoryError:
-        print(f"ls: cannot access '{path}': Not a directory")
+        print(
+            f"ls: cannot access '{path}': Not a directory",
+            file=sys.stderr
+        )
 
 def main():
     parser = argparse.ArgumentParser()
     parser.add_argument('-1', dest='one_column', action='store_true', help='list one file per line')
     parser.add_argument('-a', action='store_true', help='show hidden files')
     parser.add_argument('path', nargs='?', default='.', help='directory to list')
     args = parser.parse_args()
-    
+
     ls(args.path, args.one_column, args.a)
 
 if __name__ == "__main__":