tac is "semi-done" because of unimplemented ---regex
@@ -301,7 +301,7 @@ Utilities
| csplit | date | |
| cut | join | |
| dircolors | df | |
-| dirname | | |
+| dirname | tac | |
| du | | |
| echo | | |
| env | | |
@@ -354,7 +354,6 @@ Utilities
| stdbuf | | |
| sum | | |
| sync | | |
-| tac | | |
| tee | | |
| timeout | | |
| touch | | |
