do not allow negative -l limit.

1 files changed, 3 insertions, 1 deletions

diff --git a/uxd.rst b/uxd.rst
index a17eb1c..a6c90fd 100644
--- a/uxd.rst
+++ b/uxd.rst
@@ -88,7 +88,9 @@ by itself.
 -l length
   Stop dumping after *length* bytes (not characters). If the limit is
   reached in the middle of a multibyte character, the entire character
-  will be dumped.
+  will be dumped. Can be given in decimal, hex (with *0x* prefix), or
+  octal (with *0* prefix). Negative *length* doesn't make sense, and
+  is an error.
 
 .. stop dumping after <length> bytes (not characters).