man pages section 1: User Commands
O
- 
od(1)– octal dump
- 
on(1)– execute a command on a remote system, but with the local environment
- 
onintr(1)– shell built-in functions to respond to (hardware) signals 
- 
optisa(1)– determine which variant instruction set is optimal to use
 
    - © 2010, Oracle Corporation and/or its affiliates