Script Template

1. Shebang
2. Add the script directory to auto_path.
3. package require libraries.
4. namespace eval demo {} contains:
   • variable Version x.y
   • … Author, Copyright, Description
   • export 's
   • Variables
5. proc demo::main args {} , then others,
6. package provide demo $demo::Version
7. if source'd return
8. demo::main {*}$argv