vis(1) on FreeBSD
The text 18dcced8fb18, as FreeBSD 4.11-RELEASE, FreeBSD 4.10-RELEASE, FreeBSD 4.9-RELEASE, FreeBSD 4.8-RELEASE, FreeBSD 4.7-RELEASE shipped it.
display non-printable characters in a visual format
Flags it lists
-
-F -
-b -
-c -
-f -
-l -
-n -
-o -
-s -
-t -
-w