Script Encoding Summary

from [[ruby-core:15391]]

Normal script case            | script encoding | default external |
------------------------------+-----------------+------------------+
no -K -E, no   magic comment  | US-ASCII        | locale           |
no -K -E, have magic comment  | magic comment   | locale           |
have  -E, no   magic comment  | US-ASCII        | -E               |
have  -E, have magic comment  | magic comment   | -E               |
have  -K, no   magic comment  | -K              | -K               |
have  -K, have magic comment  | magic comment   | -K               |


-e and stdin case             | script encoding | default external |
------------------------------+-----------------+------------------+
no -K -E, no   magic comment  | locale          | locale           |
no -K -E, have magic comment  | magic comment   | locale           |
have  -E, no   magic comment  | locale          | -E               |
have  -E, have magic comment  | magic comment   | -E               |
have  -K, no   magic comment  | -K              | -K               |
have  -K, have magic comment  | magic comment   | -K               |