The Open Group Base Specifications Issue 7
IEEE Std 1003.1-2008
Copyright © 2008 The IEEE and The Open Group, All Rights reserved.

### Special Built-in Utilities

- break - exit from for, while, or until loop
- colon - null utility
- continue - continue for, while or until loop
- dot - execute commands in current environment
- eval - construct command by concatenating arguments
- exec - execute commands and open, close, or copy file descriptors
- exit - cause the shell to exit
- export - set export attribute for variables
- readonly - set read-only attribute for variables
- return - return from a function
- set - set or unset options and positional parameters
- shift - shift positional parameters
- times - write process times
- trap - trap signals
- unset - unset values and attributes of variables and functions